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Designing Trianionic Pincer and Pincer-Type Ligands for Applications in Aerobic Oxidation, Ch Bond Activation, and Alkyn...

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Title:
Designing Trianionic Pincer and Pincer-Type Ligands for Applications in Aerobic Oxidation, Ch Bond Activation, and Alkyne Metathesis
Physical Description:
1 online resource (401 p.)
Language:
english
Creator:
O'reilly, Matthew E
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Chemistry
Committee Chair:
Veige, Adam S
Committee Members:
Murray, Leslie Justin
Christou, George
Miller, Stephen Albert
Hagelin, Helena Ae

Subjects

Subjects / Keywords:
activation -- catalyst -- chromium -- metathesis -- oxidation -- pincer -- trianionic -- tungsten
Chemistry -- Dissertations, Academic -- UF
Genre:
Chemistry thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Trianionic pincer and pincer-type ligands are an emerging class of multianionic pincer ligands suited for high oxidation state metals (Mn , n= 3-6). A defining feature of trianionic pincer and pincer-type ligands is the rigid meridional coordination geometry, which provides an open metal coordination site trans to the central pincer donor atom that can be exploited for catalysis. These ligands are easily modified by selection of anionic donor atoms (e.g. C, O, N) and the ligand scaffold. As such, each trianionic pincer/pincer-type ligand imparts a unique reactivity to the metal center. In the following chapters, we explore the unique reactivity imparted by a rationally designed trianionic pincer/pincer-type ligands to (1) a chromium oxidation catalyst supported by a tBuOCO trianionic pincer ligand and (2) a tungsten alkylidyne featuring an CF3-ONO ligand for applications of alkyne metathesis and CH bond activation. tBuOCOCrIII(THF)3(2) catalyzes the aerobic oxidation of PPh3 with an exceptionally high turn-over number (TON). A kinetic investigation reveals that complex 2avoids typical deactivation pathways. Complex 2 becomes more reactive toward O2 activation when dimerized with tBuOCOCrV(O)(THF) (3), yielding a unique autocatalytic O2 activation mechanism. Probing production inhibition with OPPh3, the rate of O2 activation by 2surprisingly accelerates with higher concentrations of OPPh3. The synthesis of an isolable CrVO and (CrIV)(µ-oxo) species presents interesting models to investigate oxygen-atom transfer (OAT) reactions with phosphines. We present the first kinetic investigation of OAT directly from a (CrIV)(µ-oxo) species and conclude a unique role that donor ligand play during OAT. A CF3-ONO trianionic pincer-type supported tungsten alkylidyne (12) reacts with alkynes to form exceptionally stable tungstenabutadiene complexes that do not undergo retro-2 2-cycloaddition. Contributing to the reactions’ irreversibility, complex 12 was found to be exceptionally destabilized by an unusual orientation of the amido donor within CF3-ONO trianionic pincer-type ligand. The amido lone pair forms an inorganic enamine within a metal coordination sphere, enhancing the nucleophilicity of the W=C bond. In chapter 6, we demonstrate the enhanced nucleophilicty with the tungsten alkylidene (16) and an anionic tungsten alkylidyne (17) that activate the CH bond of –OtBu to release isobutylene.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Matthew E O'reilly.
Thesis:
Thesis (Ph.D.)--University of Florida, 2013.
Local:
Adviser: Veige, Adam S.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-08-31

Record Information

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Applicable rights reserved.
Classification:
lcc - LD1780 2013
System ID:
UFE0045726:00001

MISSING IMAGE

Material Information

Title:
Designing Trianionic Pincer and Pincer-Type Ligands for Applications in Aerobic Oxidation, Ch Bond Activation, and Alkyne Metathesis
Physical Description:
1 online resource (401 p.)
Language:
english
Creator:
O'reilly, Matthew E
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Chemistry
Committee Chair:
Veige, Adam S
Committee Members:
Murray, Leslie Justin
Christou, George
Miller, Stephen Albert
Hagelin, Helena Ae

Subjects

Subjects / Keywords:
activation -- catalyst -- chromium -- metathesis -- oxidation -- pincer -- trianionic -- tungsten
Chemistry -- Dissertations, Academic -- UF
Genre:
Chemistry thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Trianionic pincer and pincer-type ligands are an emerging class of multianionic pincer ligands suited for high oxidation state metals (Mn , n= 3-6). A defining feature of trianionic pincer and pincer-type ligands is the rigid meridional coordination geometry, which provides an open metal coordination site trans to the central pincer donor atom that can be exploited for catalysis. These ligands are easily modified by selection of anionic donor atoms (e.g. C, O, N) and the ligand scaffold. As such, each trianionic pincer/pincer-type ligand imparts a unique reactivity to the metal center. In the following chapters, we explore the unique reactivity imparted by a rationally designed trianionic pincer/pincer-type ligands to (1) a chromium oxidation catalyst supported by a tBuOCO trianionic pincer ligand and (2) a tungsten alkylidyne featuring an CF3-ONO ligand for applications of alkyne metathesis and CH bond activation. tBuOCOCrIII(THF)3(2) catalyzes the aerobic oxidation of PPh3 with an exceptionally high turn-over number (TON). A kinetic investigation reveals that complex 2avoids typical deactivation pathways. Complex 2 becomes more reactive toward O2 activation when dimerized with tBuOCOCrV(O)(THF) (3), yielding a unique autocatalytic O2 activation mechanism. Probing production inhibition with OPPh3, the rate of O2 activation by 2surprisingly accelerates with higher concentrations of OPPh3. The synthesis of an isolable CrVO and (CrIV)(µ-oxo) species presents interesting models to investigate oxygen-atom transfer (OAT) reactions with phosphines. We present the first kinetic investigation of OAT directly from a (CrIV)(µ-oxo) species and conclude a unique role that donor ligand play during OAT. A CF3-ONO trianionic pincer-type supported tungsten alkylidyne (12) reacts with alkynes to form exceptionally stable tungstenabutadiene complexes that do not undergo retro-2 2-cycloaddition. Contributing to the reactions’ irreversibility, complex 12 was found to be exceptionally destabilized by an unusual orientation of the amido donor within CF3-ONO trianionic pincer-type ligand. The amido lone pair forms an inorganic enamine within a metal coordination sphere, enhancing the nucleophilicity of the W=C bond. In chapter 6, we demonstrate the enhanced nucleophilicty with the tungsten alkylidene (16) and an anionic tungsten alkylidyne (17) that activate the CH bond of –OtBu to release isobutylene.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Matthew E O'reilly.
Thesis:
Thesis (Ph.D.)--University of Florida, 2013.
Local:
Adviser: Veige, Adam S.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-08-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2013
System ID:
UFE0045726:00001


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1 DESIGNING TRIANIONIC PINCER AND PINCER TYPE LIGANDS FOR APPLICATIONS IN AEROBIC OXIDATION C H BOND ACTIVATION, A ND ALKYNE METATHESIS By REILLY A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVER SITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2013

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2 2013 M atthew E O R eilly

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3 To my family

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4 ACKNOWLEDGMENTS Upon realizing thi s accomplishment, I am deeply grateful for those who developed me as a person and as a chemist. First, I thank my mother and father for their unconditional love and support throughout these years. I am thankful to my five brothers, who instilled in me a co mpetive spirit. In particular, my little brother Thomas who is far more intelligent than me, used sibling r i valry to push me to study at an early age. I thank Lee University for providing a reasonably priced education that my parents could afford and som e of my most influental mentors. One of those mentors is my organic chemistry professor, Edward Brown, who fostered my passion for chemistry. Additionaly, I am also grateful for the opportunities to work as a REU student in the research laboratories of Pro f. Gunnoe and Prof. Braunstein. I am thankful for my good friend and research mentor, Robe rto Pattacini, who taught me many synthetic skills. I thank my advisor, Adam S. Veige, for his constant guidance and advice, and the Veige group who have been suppor tive colleagues and good friends. Also I wish to thank and acknowledge two undergraduate students, Joseph Falkowski and Trevor del Castillo, who have contributed to the work presented here. I want to thank three people who deserve special recognition My brother Thomas mentioned earlier. My lovely wife Olivia, you have given me the greatest happiness You have provided an unwavering support and taught me to discipline my life and my passion for chemistry. I thank God for you and look adv entures together My grandfather John Galiger, you taught me to be content, to Finally I want to

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5 thank the Big Man upstairs, who has given me the ability to understand his masterwork and has provided all these opportunities.

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6 TABLE OF CONTENTS p age ACKNOWLEDGMENTS ................................ ................................ ................................ .. 4 LIST OF TABLES ................................ ................................ ................................ .......... 11 LIST OF FIGURES ................................ ................................ ................................ ........ 15 LIST OF ABBREVIATIONS ................................ ................................ ........................... 29 A BSTRACT ................................ ................................ ................................ ................... 33 CHAPTER 1 INTRODUCTION INTO TRIANIONIC PINCER AND PINCER TYPE LIGANDS .... 35 1.1 Pincer and Pincer Type Ligands ................................ ................................ ....... 35 1.2 Developing Trianionic Pincer and Pincer Type Ligands ................................ .... 35 1.2.1 Pincer Ligands for High Oxidation State Metals ................................ ...... 35 1.2.2 Versatility of the Trianionic Pincer and Pincer type Ligand ...................... 36 1.3 Rational Approaches to Create Reactive Complexes ................................ ....... 38 1.3.1 Confined Medional Geometry with Early Transition Metals ..................... 38 1 .3.2 Constrained Bite Angles of Trianionic Pincer Ligands ............................. 39 1.3.3 Open Coordination Site ................................ ................................ ........... 40 1.3.4 Insertion of Unsaturated Substr ate into Central Pincer M C Bond .......... 41 1.3.5 Electronically Unsaturated Metal Centers ................................ ................ 41 1.3.6 Constrained Donor Atom Orientation ................................ ....................... 41 1.3.7 Support High Oxidation State Metals ................................ ....................... 42 1.3.8 Redox active Pincer Ligands ................................ ................................ ... 42 1.4 Designing Trianionic Pincer and Pincer type Ligands for Applications in ...................... 43 2 AEROBIC OXIDATION CA TALYST FEATURING BY A TRIANIO NIC PINCER C r III /C r V COUPLE AVOIDING COMM ON CATALYST DEACTIVA TION PATHWAYS ................................ ................................ ................................ ............ 49 2.1 Introduction ................................ ................................ ................................ ....... 49 2.2 Results and Discussion ................................ ................................ ..................... 51 2.2.1 Synthesis of [ t BuOCO]HK 2 t BuOCO]Cr III (THF) 3 (2) ...... 51 2.2.2 Synthesis of [ t ................................ ................... 53 2.2.3 Aerobic Oxidation of PPh 3 Catalyzed by [ t ........ 55 2.2.4 Prelude to the Kinetic Inve stigation into the Mechanism O 2 Activation by 2 ................................ ................................ ................................ ............... 55 2.2.5 UV vis Measurements for the Rate of O 2 Activation by 2 ........................ 56 2.2.6 O 2 Cleava ge Rate Dependence on [2], [O 2 ], [THF], and Temperature .... 56

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7 2.2.7 Characterization of the Autocatalytic Intermediate: the Chromium(IV) oxo Dimer {[ t BuOCO]Cr IV (THF)} 2 ( O) (4) ................................ .................. 58 2.2.8 Electron Paramagnetic Resonance Measurements of 4 .......................... 60 2.2.9 Proposed Mechanism o f O 2 Activation ................................ .................... 62 2.2.10 Kinetic Simulations ................................ ................................ ................ 63 2.2.11 Product Inhibition Studies ................................ ................................ ...... 65 2.2.12 Isolation of a Catalytic Intermediate [ t BuOCO]Cr(OPPh 3 ) 2 (5) ............... 65 2.2.13 Cyclic Voltametry of 2, 4, and 5 ................................ ............................. 66 2.3 Conclusions ................................ ................................ ................................ ...... 67 2.4 Experimental Section ................................ ................................ ........................ 68 2.4.1 General Considerations ................................ ................................ ........... 68 2.4.2 Analytical Techniques ................................ ................................ .............. 69 2.4.3 Calculations ................................ ................................ ............................. 70 2.4.4 Synthesis of [ t BuOCO]K 2 ................................ ...................... 71 2.4.5 Synthesis of [ t BuOCO]Cr III (THF) 3 (2) ................................ ....................... 71 2.4.6 Synthesis of [ t BuOCO]Cr V ................................ .................... 72 2.4.7 Synthesis of {[ t BuOCO]Cr IV (THF)} 2 ( O) (4) ................................ ............ 73 2.4.8 Synthesis of [ t BuOCO]Cr III (OPPh 3 ) 2 (5) ................................ ................... 73 2.4.9 General Procedure for the Catalytic Oxidation of PPh 3 with O 2 by 2 ....... 73 2.4.10 General Procedure for the Catalytic Oxidation of PPh 3 with air by 2 ..... 74 2.4.11 Stoichiometric 18 O 2 Catalytic PPh 3 Oxidation Reaction ......................... 74 2.4.12 General Sample Preparation for Kinetic Measurements ........................ 74 2.4.13 Kinetic Simulations ................................ ................................ ................ 75 2.4.14 [2] vs time: Oxidation of 2 with O 2 in THF ................................ .............. 75 2.4.15 Variable Te mperature: Oxidation of 2 with O 2 in THF ............................ 76 3 THE INFLUENCE OF REV ERSIBLE TRIANIONIC P INCER OCO 3 OXO Cr IV DIMER FORMATION ([Cr IV ] 2 ( O)) AND DONOR LIGANDS IN OXYGEN ATOM TRANSFER (OAT) ................................ ................................ ...................... 96 3.1 Introduction ................................ ................................ ................................ ....... 96 3.2 Results and D iscussion ................................ ................................ ..................... 98 3.2.1 Identity of the Active OAT Agent in THF ................................ .................. 98 3.2.2 Mechanism of OAT from Mononuclear 3 and 3a ................................ ..... 99 3.2.3 [PPh 3 ] Dependence ................................ ................................ ............... 100 3.2.4 Variable Temperature Studies and Eyring Plot ................................ ...... 100 3.2.5 PR 3 Size Rate Dependence ................................ ................................ .. 100 3.2.6 Role of Donor Ligands on OAT ................................ ............................. 101 3.2.7 Synthesis and Characterization of [ t BuOCO]Cr V (O )(CH 2 PPh 3 ) (6) ........ 102 3.2.8 Role of Dinuclear oxo Dimer {[ t BuOCO]Cr IV (THF)} 2 ( O) (4) in OAT .. 103 3.3 Conclusions ................................ ................................ ................................ .... 107 3.4 Experimental Section ................................ ................................ ...................... 109 3.4.1 General Considerations ................................ ................................ ......... 109 3.4.2 Analytical Techniques ................................ ................................ ............ 110 3.4.3 Synthesis of [ t BuOCO]Cr V O(CH 2 PPh 3 ) (6) ................................ ............ 111 3.4.4 [PPh 3 ] vs. k obs [ t BuOCO]Cr V (O)(THF) (3) in THF ................................ .. 112 3.4.5 [OPPh 3 ] vs. k obs. [ t BuOCO]Cr V (O)(THF) (3) in TH F ................................ 112

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8 3.4.6 Variable Temperature. [ t BuOCO]Cr V (O)(THF) in THF ........................... 112 3.4.7 Solvent Effects. OAT in MeCN, CH 2 Cl 2 and THF ................................ 113 3.4.8 Substrate Effects. OAT to PMe 3 PPh 3 and P t Bu 3 ................................ 113 3.4.9 [PPh 3 ] vs k obs : OAT from {[ t BuOCO]Cr IV (THF)} 2 ( O ) (4) to PPh 3 in CH 2 Cl 2 ................................ ................................ ................................ ......... 114 4 REACTIONS OF AN ONO 3 TRIANIONIC PINCER TYPE TUNGSTEN ALKYLIDYNE WITH ALKY NES AND NITRILES: PR OBING AN UNUSUALLY STABLE TUNGSTENABUTA DIENE ................................ ................................ ..... 126 4.1 Introduction ................................ ................................ ................................ ..... 126 4.2 Results and Discussion ................................ ................................ ................... 129 4.2.1 Synthesis and Characteriz ation of [CF 3 ONO]H 3 (8) .............................. 129 4.2.2 Synthesis and Characterization of [CF 3 ONO]W=CH( t Bu)(O t Bu) (9) ..... 129 4.2.3 Synthesis and Characte rization of {[CF 3 t Bu)(O t Bu)}{MePPh 3 } (10) ................................ ......................... 130 4.2.4 In situ Synthes is of {CH 3 PPh 3 }{[CF 3 t Bu(OTf)} (11) and [CF 3 t Bu)(OEt 2 ) (12) ................................ ................................ .. 130 4.2.5 Synthesis and Characterization of [CF 3 ONO]W[ 2 C( t Bu)C(Me)C(Ph)] (13) ................................ ................................ ................................ .............. 132 4.2.6 Synthesis and Characterization of [CF 3 ONO]W[ 2 C( t Bu)C(Me)C( t Bu)] (14) ................................ ................................ .............. 134 4.2.7 Synthesis and Characterization of [CF 3 ONO]W[ 2 C( t Bu)C(CH 2 (CH 2 ) 4 CH 2 )C] (15) ................................ ................................ ... 135 4.2.8 Computational Studies ................................ ................................ .......... 137 4.2.9 15 N NMR Studies ................................ ................................ ................... 139 4.2.10 Electronic Factors Contributing to an Irreversible [2+2] Cycloaddition 140 4.2.11 Nitrile Alkyne Cross Metathesis ................................ ........................... 141 4.3 Conclusion ................................ ................................ ................................ ...... 142 4.4 Experimental ................................ ................................ ................................ ... 144 4.4.1 General Considerations ................................ ................................ ......... 144 4.4.2 Analytical Techniques ................................ ................................ ............ 144 4.4.3 Calculations ................................ ................................ ........................... 144 4.5.4 Synthesis of 2,2' (azanediylbis(3 methyl 6,1 phenylene))bis(1,1,1,3,3,3 hexafluoropropan 2 ol) (8) ................................ 145 4.4.5 Synthesis of [C F 3 ONO]W=CH t Bu(O t Bu) (9) ................................ ......... 146 4.4.6 Synthesis of {CH 3 Ph 3 P}{[CF 3 t Bu(O t Bu)} (10) ....................... 147 4.4.7 Synthesis of {CH 3 PPh 3 }{[CF 3 C t 3 PPh 3 }{OTf} (11) ................................ ................................ ................................ .............. 148 4.4.8 Synthesis of [CF 3 t Bu)(OEt 2 ) (12) ................................ ........ 148 4.4.9 Synthesis of [CF 3 ONO]W[ 2 C( t Bu) C(Me)C(Ph)] (13) .......................... 149 4.4.10 Synthesis of [CF 3 ONO]W[ 2 C( t Bu)C(Me)C( t Bu)] (14) ........................ 150 4.4.11 Synthesis of [CF 3 ONO]W[ 2 C( t Bu)C(CH 2 (C H 2 ) 4 CH 2 )C] (15) ............. 151 5 AN ONO 3 TRIANIONIC PINCER TYPE LIGAND FOR GENE RATING HIGHLY NUCLEOPHILIC METAL CARBON MULTIPLE BOND S: AN INORGANIC ENAMINE ................................ ................................ ................................ ............. 164

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9 5.1 Introduction ................................ ................................ ................................ ..... 164 5.2 Results ................................ ................................ ................................ ............ 168 5.2.2 Synthesis and Characterization of [CF 3 ONO]W=CH(Et)(O t Bu) (16) ..... 168 5.2.3 Synthesis and Characterization of {[CF 3 t Bu)}{MePPh 3 } (17) ................................ ........................... 170 5.2.4 Reactivity Studies, Nucleophilic at Carbon ................................ ............ 170 5.2.5 Isobutylene Expulsion from 17 ................................ .............................. 171 5.2.6 Catalytic Isobutylene Expulsion from 16 ................................ ................ 171 5.2.7 Computational Results ................................ ................................ .......... 172 5.3 Discussion ................................ ................................ ................................ ...... 174 5.3.1 An Enhanced Nucleophilic Reactivity from 17 ................................ ....... 174 5.3.2 Single Point DFT Calculations of 17 ................................ ...................... 174 5.3.3 Isobutylene Expulsion from 10 ................................ .............................. 175 5.3.4 Isobutylene Expulsion from 16 ................................ .............................. 177 5.4 Conclusion ................................ ................................ ................................ ...... 178 5.5 Experimental ................................ ................................ ................................ ... 179 5.5.1 General Considerations ................................ ................................ ......... 179 5.5.2 Analytical Techniques ................................ ................................ ............ 179 5.5.3 Calculations ................................ ................................ ........................... 179 5.5.5 Synthesis of [CF 3 ONO]W=CH(Et)(O t Bu) (16) ................................ ....... 180 5.5.6 Synthesis of {[CF 3 t Bu)}{MePPh 3 } (17) ....................... 181 5.5.7 Preparation of [CF 3 ONO]W=C(CH 3 )(Et)(O t Bu) (18) ............................ 1 81 5.5.8 Preparation of [CF 3 ONO]W=CH (Et)(OSiMe 3 ) (19) ............................... 182 5.5.9 Synthesis of [CF 3 ONO]W(O)( n Pr) (20) ................................ ................. 183 6 FUTURE WORK TOWARDS AN ACTIVE ALKYNE MET ATHESIS CATALYST FE ATURING A NEW TRIANI ONIC ONO PINCER TYPE LIGAND. ..................... 195 6.1 Introduction ................................ ................................ ................................ ..... 195 6.2 Results and Discussion ................................ ................................ ................... 195 6.2.1 Progess towards the Synthesis of [pyr ONO]H 3 ................................ .... 195 6.3 Experimental ................................ ................................ ................................ ... 197 6.3.1 General Co nsiderations ................................ ................................ ......... 197 6.3.2 Analytical Techniques ................................ ................................ ............ 197 6.3.3 Synthesis of 2,5 bis(3 ( tert butyl) 2 methoxyphenyl) 1H pyrrole ........... 197 APPENDIX: SUPPORTING INFORMATI ON ................................ .............................. 202 A.1 NMR Data ................................ ................................ ................................ ....... 202 A.2 IR Data ................................ ................................ ................................ ........... 282 A.3 UV Vis Data ................................ ................................ ................................ .... 286 A.4 MS Data ................................ ................................ ................................ ......... 287 A.5 EPR Data ................................ ................................ ................................ ....... 289 A.6 CV Data ................................ ................................ ................................ .......... 290 A.7 X Ray Crystallographic Data ................................ ................................ .......... 291 A.8 DFT Calculations ................................ ................................ ............................ 363

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10 LIST OF REFERENCES ................................ ................................ ............................. 379 BIOGRAPHICAL SKETCH ................................ ................................ .......................... 401

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11 LIST OF TABLES Table page 2 1 Average calculated rate constants for the oxidation of 2 (1.84 x10 4 M) with O 2 (1.66 x10 3 M) in THF at 25 C, 20 C, and 0 C. ................................ .......... 92 3 1 Rate const ants for OAT of 3a (0.30 mM) to PMe 3 PPh 3 and P t Bu 3 (0.77 mM) in THF at 15C. d[ 3a ]/dt = k obs [ 3a ] where k obs (s 1 ) = k 1 [phosphine]. ............... 118 3 2 Rate constants for OAT of 3 (2.97 x10 4 M) to PPh 3 (7.70 x10 4 M) at 22 C. d[ 3 ]/dt = k obs [ 3 ] where k obs = k 1 [PPh 3 ]. ................................ ............................ 119 3 3 Simulated k 1 (s 1 ) and k 1 (M 1 s 1 ) values obtained from the simulation of the [ 3 ] vs time plots. (CH 2 Cl 2 22C) ................................ ................................ ....... 124 4 1 Selected metric parameters for the WC 3 rings of 19 20 and 21 ..................... 158 4 2 Selected metric parameters for the WC 3 rings of 19 2 0 and 21 ..................... 158 4 3 15 N NMR chemical shifts of 9 15 ................................ ................................ ..... 162 5 1 Selected bond lengths () for the single crystal X ray structure of 9 and DFT geometry optimized structures of 16' 16 Me' and 17' ................................ .... 189 A 1 1 H, 13 C, 19 F and 15 N chemical shifts in compounds 8 15 ................................ 209 A 2 1 H, 13 C, 19 F and 15 N chemical shifts in compounds 8,16 20 in C 6 D 6 ................ 245 A 3 Crystal data, structure solution and refinement for 1 ................................ ....... 293 A 4 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 1 . ................................ ................................ ............. 294 A 5 Bond lengths (in ) for 1 ................................ ................................ .................. 295 A 6 Bond angles () for 1 ................................ ................................ ........................ 295 A 7 Anisotropic displacement parameters ( 2 x 10 3 ) for 1 ................................ .... 298 A 8 Crystal data a nd structure refinement for 2 ................................ ..................... 300 A 9 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 2 ................................ ................................ .............. 301 A 10 Bond lengths [] for 2 ................................ ................................ ...................... 302 A 11 Bond angles [] for 2 ................................ ................................ ........................ 303

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12 A 12 Anisotropic displacement parameters ( 2 x 10 3 ) for 2 ................................ .... 304 A 13 Crystal data and structure refinement for 3 ................................ ..................... 307 A 14 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacem ent parameters ( 2 x 10 3 ) for 3 .. ................................ ................................ ............. 308 A 15 Bond length [] for 3 ................................ ................................ ........................ 308 A 16 Bond angles [] for 3 ................................ ................................ ........................ 309 A 17 Anisotropic displacement parameters ( 2 x 10 3 ) for 3 ................................ .... 310 A 18 X ray crystallographic structure parameters and refinement data for 4 ........... 312 A 19 Atomic coordinates (x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 4 .. ................................ ................................ ............. 313 A 20 Bond lengths [] for 4 ................................ ................................ ...................... 314 A 21 Bond angles [] for 4 ................................ ................................ ........................ 314 A 22 Anisotropic displacement parameters ( 2 x 10 3 ) for 4 ................................ .... 315 A 23 Crystal data and structure refinement for 5 ................................ ..................... 317 A 24 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 5 .. ................................ ................................ ............. 318 A 25 Bond lengths [] for 5 ................................ ................................ ...................... 319 A 26 Bond angles [] for 5 ................................ ................................ ........................ 320 A 27 Anisotropi c displacement parameters ( 2 x 10 3 ) for 5 ................................ .... 321 A 28 Crystal data and structure refinement for 6 ................................ ..................... 324 A 29 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 6 .. ................................ ................................ ............. 325 A 30 Bond lengths [] for 6 ................................ ................................ ...................... 326 A 31 Bond angles [ ] for 6 ................................ ................................ ........................ 327 A 32 Anisotropic displacement parameters ( 2 x 10 3 ) for 6 ................................ .... 328

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13 A 33 Crystal data and structure refinement for 12 ................................ ................... 331 A 34 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 12 .. ................................ ................................ ........... 332 A 35 Bond angles [ ] f or 12 ................................ ................................ ...................... 333 A 36 Bond lengths [ ] for 12 ................................ ................................ .................... 334 A 37 Anisotropic displacement parameters ( 2 x 10 3 ) for 12 ................................ .. 334 A 38 Crystal data and structure refinement for 13 ................................ ................... 336 A 39 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) fo r 13 .. ................................ ................................ ........... 337 A 40 Bond lengths [] for 13 ................................ ................................ .................... 338 A 41 Bond angles [] for 13 ................................ ................................ ....................... 339 A 42 Anisotropic displacement parameters ( 2 x 10 3 ) for 13 ................................ .. 340 A 43 Crystal data and structure refinement for 14 ................................ ................... 342 A 44 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 14 .. ................................ ................................ ........... 343 A 45 Bond lengths [] for 14 ................................ ................................ .................... 344 A 46 Bond angles [] for 14 ................................ ................................ ...................... 345 A 47 Anisotropic displacement parameters (2x 103) for 14 ................................ .. 346 A 48 Crystal data and s tructure refinement for 15 ................................ ................... 348 A 49 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters (2x 10 3 ) for 15 .. ................................ ................................ ........... 349 A 50 Bond lengths [] for 15 ................................ ................................ .................... 350 A 51 Bond angles [] for 15 ................................ ................................ ...................... 351 A 52 Anisotropic displacement parameters ( 2 x 10 3 ) fo r 15 ................................ .. 352 A 53 Crystal data and structure refinement for 16 ................................ ................... 354

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14 A 54 Atomic coordinates ( x 10 4 ) and equivalent isotropic displ acement parameters ( 2 x 10 3 ) for 16 .. ................................ ................................ ........... 355 A 55 Bond lengths [] for 16 ................................ ................................ .................... 356 A 56 Bond angles [] for 16 ................................ ................................ ...................... 356 A 57 Anisotropic displacement parameters ( 2 x 10 3 ) for 16 ................................ .. 357 A 58 Crystal data and structure refinement for 20 ................................ ..................... 359 A 59 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 20 .. ................................ ................................ ........... 360 A 60 Bond lengths [] for 20 ................................ ................................ .................... 360 A 61 Bond angles [] for 20 ................................ ................................ ...................... 361 A 62 Anisotropic displacement parameters ( 2 x 10 3 ) for 20 ................................ .. 362 A 63 Atomic coordinates for the geometry optimized structure of 12 ....................... 363 A 64 Atomic coordinates for the geometry optimized structure of 13 ....................... 364 A 65 Atomic coordinates for the geometry optimized structure of [CF 3 ONO]W N(OEt 2 ). ................................ ................................ ............................. 366 A 66 Atomic coordinates of the geometry optimization calculation for ............... 369 A 67 Atomic coordinates of the geometry optimization calculation for 16 ......... 371 A 68 Atomic coordinates of the geometry optimization calculation for ............... 373 A 69 Atomic coordinates of the geometry optimization calculation for ............... 375

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15 LIST OF FIGURES Figure page 1 1 The original PCP pincer ligand ( A ) by Shaw, 1 and PNP pincer type ligand ( B ) by Ozerov. 2 ................................ ................................ ............................... 45 1 2 A coordinately saturated high valent metal ( M) featuring a pincer ligand A and a low coordinate high valent metal with a trianionic pincer ligand B ....... 45 1 3 Current library of demonstrated trianionic pincer ligands; and pincer type ligan ds. ................................ ................................ ................................ ........... 46 1 4 Coordination geometry changes upon imposing a trianionic pincer ligand on a tetrahedral metal center. ................................ ................................ ......... 47 1 5 Bite ang les and linker spacing. ................................ ................................ ....... 47 1 6 C reating open coordination sites ................................ ................................ ... 47 1 7 Insertion into the OCO pincer C M bond.. ................................ ...................... 48 1 8 Constrained amido orientation using trianionic pincer type ligand. ................. 48 1 9 Potential redox states of a non innocent pincer type ligand. .......................... 48 2 1 General mechanism for substrate oxidation including catalyst deactivation pathways of product inhibition and reversible formation of a M O M intermediate. ................................ ................................ ................................ ... 77 2 2 Additional coordination site provided by a trianionic pincer ligand over tetradentate ligands. ................................ ................................ ....................... 77 2 3 Synthesis of 1 ................................ ................................ ................................ 77 2 4 Synthesis of 2 ................................ ................................ ................................ 78 2 5 Molecular structure of 2 with ellipsoids at 50% probability. ............................. 78 2 6 Activation of O 2 by 2 to yield complex 3 ................................ ........................ 79 2 7 Molecular structure of 3 with ellipsoids at 50% probability. ............................. 79 2 8 Plot of the SOMO ( A LUMO ( B ) of model complex contour level 0.03 a.u.. ................................ ................................ ................................ 80 2 9 Aerobic oxidation of PPh 3 catalyzed by complex 2 ................................ ........ 80 2 10 UV vis spectral change of 2 in THF upon addition of O 2 (25 C). ................... 81

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16 2 11 Concentration vs time (s) for the oxidation of 2 by O 2 in THF; within 1 st 80% (blue), after 80% (red) (25 C). ................................ ............................... 81 2 12 Concentration ( 2 ) vs time (s) for the oxidation of 2 (0.55 1.65 (x10 4 ) M) with O 2 (1.66 x10 3 M) in THF (25 C). ................................ ............................ 82 2 13 Plot of 2 2 ] ([ 2 ] = 0.55 1.65 x10 4 M; [O 2 ] = 1.66 x10 3 M (THF, 25 C). ................................ ................................ ................................ ............ 82 2 14 Concentration ( 2 ) vs time (s) for the oxidation of 2 (1.10 x10 4 M) with O 2 (1.66 6.66 (x1 0 3 ) M) in THF (25 C). ................................ ............................ 83 2 15 Plot of rate 2 2 ] ([ 2 ] = 1.10 x10 4 M; [O 2 ] = 1.66 6.66 (x10 4 ) M) in THF (25 C). ................................ ................................ ............................... 83 2 16 Plot of rate 1 X THF ([ 2 ] = 1.10 x10 4 M; [O 2 ] =1.66 x10 3 M; THF/hexane (mL:mL) = 2.5:0.5, 2.0:1.0, 1.5:1.5) at 25 C. ............................ 84 2 17 Concentration of 2 (1.84 x10 4 M) vs time in T HF upon addition of O 2 (1.66 x10 3 M) at 40 C (red), 20 C (yellow), 10 C (light blue), and 0 C (dark blue). ................................ ................................ ................................ .............. 84 2 18 Concentration of 2 vs time (s) for the oxidation of 2 (1.10 x10 4 M) by O 2 ( 1.66 x10 3 M ) with increasing [ 3 ] (0, 5.5 x10 5 and 1.10 x10 5 M) in THF (25 C). ................................ ................................ ................................ ........... 85 2 19 2 2 (1.10 x10 4 M) by O 2 (1.66 x10 3 M) with increasing [ 3 ] (0, 0.55 x10 4 and 1.10 x10 4 M) in THF (25 C). .............. 85 2 20 Equilibrium between 2 and 3 and the dim er adduct 5 ................................ .... 86 2 21 Molecular structure of {[ t BuOCO]Cr IV (THF)} 2 O ( 5 ) with ellipsoids drawn at the 50% probability level . ................................ ................................ ............... 86 2 22 The bonding MO and ligand field splitting diagram of the Cr IV ion in 5 ....... 87 2 23 Variable temperature high frequency (240 GHz) powder EPR spectra of major 5 and minor 2 ................................ ................................ ....................... 87 2 24 Simulated (a) and experimental (b) powder EPR spectra of 5 and 2 at 240 GHz and 4.5 K. ................................ ................................ ............................... 88 2 25 Molecular structure of {[ t BuOCO]Cr IV (THF)} 2 O ( 5 ) w ith ellipsoids drawn at the 50% probability level. ................................ ................................ ................ 89 2 26 Proposed mechanism for O 2 activation by 2 ................................ .................. 90 2 27 Simulated [ 2 ] (0.5 5 1.65 x10 4 M) vs time (s) at [O 2 ] = 1.66 x10 3 M.. ........... 91

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17 2 28 Simulated [ 2 ] (1.10 x10 4 M) vs time (s) at different concentrations of [O 2 ] (1.66 6.66 x10 3 M).. ................................ ................................ .................... 91 2 29 Simulated [ 2 ] vs time for the oxidation of 2 (1.65 x10 4 M and 1.84 x10 4 M) with O 2 (1.66 x10 3 M) using the average calculated rate constants from Table 1. ................................ ................................ ................................ .......... 92 2 30 A plot of [ 2 ] vs time with increasing [OPPh 3 ] (0 0.1 M). [O 2 ] = 1.66 x10 3 M and [ 2 ] = 1.10 x10 4 M (THF, 25 C). ................................ .......................... 93 2 31 Synthesis of 4 ................................ ................................ ................................ 93 2 32 Molecular structure of 4 with ellipsoids at 50% probability. Hydrogen atoms and CH 2 Cl 2 removed for clarity. ................................ ................................ ...... 94 2 33 New general mechanism for substrate o xidation featuring ........................... 95 3 1 General mechanism for substrate oxidation that includes reversible formation of a M O M intermediate. ................................ .............................. 115 3 2 EPR spectra (23 C) of recrystallized [ t BuOCO]Cr V (O)(THF) ( 3 ) in toluene (blue, 1.29 mM) and 50:50 THF/CH 2 Cl 2 (orange, 1.5 mM). .......................... 115 3 3 Equilibrium between 3 and 3a ................................ ................................ ..... 115 3 4 Normalized EPR spectra (23 C) of 3 ................................ ............................... 116 3 5 Oxygen atom transfer reac tion from 3a to PPh 3 ................................ .......... 116 3 6 UV vis spectral change of 3a in THF upon addition of PPh 3 and a plot of [ 3a ] (0.11 mM) vs time (s) upon addition of PPh 3 (1.1 mM) in THF. ............. 116 3 7 A plot of ln[ 3a ] vs time. ................................ ................................ ................. 117 3 8 Plot depicting first order dependency in [PPh 3 ] (0.71 2.14 mM) for the OAT from 3a (0.11 mM) at 15 C.. ................................ ................................ 117 3 9 Eyring plot for the OAT from 3a (0.186 mM ) to PPh 3 (1.59 mM) in THF between 0 40 C (R 2 = 0.9875). ................................ ................................ 118 3 10 Proposed mech anism for OAT. ................................ ................................ .... 118 3 11 Zero order dependency on [OPPh 3 ] (0 1.31 mM) in the OAT from 3a (0.163 mM) to PPh 3 (1.59 mM) in THF at 22 C. ................................ .......... 119 3 12 Synthesis of complex 6 ................................ ................................ ................ 119

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18 3 13 Cyclic voltammograms of 3 in CH 2 Cl 2 (red), and 6 in CH 2 Cl 2 (blue) in 0.1 M TBAH/CH 2 Cl 2 at 100 mVs 1 ; glassy carbon working and Ag/Ag + referenc e electrodes. ................................ ................................ ................................ .... 120 3 14 Solution EPR spectrum of 6 in hexanes (black) and simulated spectrum using EasySpin.3.1.6.. ................................ ................................ .................. 120 3 15 Mole cular structure of [ t BuOCO]Cr V O(CH 2 PPh 3 ) ( 6 ) drawn in two perspectives. ................................ ................................ ............................... 121 3 16 UV vis spectral change of 4 (purple) in CH 2 Cl 2 upon addition of PPh 3 (for reference the UV vis spectra of 2 (g reen) and 3 ( red) in THF are included). 121 3 17 A plot of [ 4 ] (0.16 mM) vs time (s) and ln[ 4 ] vs time upon addition of PPh 3 (1.10 mM) in CH 2 Cl 2 (22C). ................................ ................................ ......... 122 3 18 A plot of 4 (1.56 x10 4 M) vs time upon the addition of PPh 3 (1.10 4.42 x10 3 M) in CH 2 Cl 2 (22 C). ................................ ................................ ........... 122 3 19 Proposed mechanism of OAT from 43 19 to PPh 3 ................................ ..... 123 3 20 A plot of [ 4 ] (3.11, 1.56, and 0.78 x10 4 M) vs time (s) upon the addition of PPh 3 (1.10 x10 3 M) in CH 2 Cl 2 ................................ ................................ ..... 124 3 21 T he average 2[ 4 ] [Cr] tot ln[ 4 ] vs time for the addition of PPh 3 (1.1 x10 3 M) into a 3.31 x10 4 M solution of 4 in CH 2 Cl 2 ................................ ............. 124 3 22 Simulated (solid lines) and experimental (dotted lines) of [ 4 ] vs time at different concentration of 4 (0.78, 1.56, and 3.11 x10 4 M). .......................... 125 3 23 Absorption spectrum of 3 (2.36 x10 4 M) in CH 2 Cl 2 (red) and after (9.1 s) addition of PPh 3 (1.87 x10 3 M) t o form 4 (red). ................................ ............ 125 4 1 Ancillary ligand rearrangement during alkyne metathesis. ........................... 153 4 2 Delicate balance of lowering activation energy while keeping the alkylidyne and metallacyclobutadiene thermoneutral. ................................ ................... 153 4 3 The push pull electronic effect of the [CF 3 ONO] pincer type ligand and the inorganic enamine bonding stru cture. ................................ ........................... 153 4 4 Initial proposed synthesis of an [CF3 ONO] ligand. ................................ ...... 154 4 5 Synthesis of 8 ................................ ................................ .............................. 154 4 6 Synthesis of 9 ................................ ................................ .............................. 154 4 7 Synthesis of 10 ................................ ................................ ............................ 154

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19 4 8 Synthesis of 11 and 12 ................................ ................................ ................ 155 4 9 Molecular structure of [CF 3 t Bu)(OEt 2 ) ( 12 ) with ellipsoids drawn at 50% Probability level, with hydrogens removed for clarity. ............ 155 4 10 Synthesis of tungstenacyclobutadienes 13 14 and 15 ............................... 156 4 11 Molecular structure of [CF 3 2 C( t Bu)C(Me)C(Ph)] ( 19 ) with ellipsoids drawn at 50% probability level ................................ ..................... 157 4 12 Reported X ray crystallographic bond length and angles of tungstena cyclo buta diene complexes ................................ ........................... 157 4 13 Fluxional WC 3 ring conformations. ................................ ............................... 158 4 14 Molecular structure of [CF 3 ONO]W[C( t Bu)C(Me)C( t Bu)] ( 14 ) with ellipsoids drawn at 50% probability level . ................................ .................... 159 4 15 Molecular structure of [CF 3 ONO]W[C( t Bu)C(CH 2 ) 6 C] ( 15 ) with ellipsoids drawn at 50% probability level ................................ ................................ ..... 159 4 16 DFT geometry optimized structures of 12 and 13 wi th calculated bond lengths (red) and crystallographic determined lengths (black). .................... 160 4 17 Truncated MO diagram of 12 and 13 (isovalues = 0.051687). ..................... 161 4 18 Amido lone pair orientation for varying ligand systems of tungsten alkylidyne and tungstenacyclobutadiene complexes ( I II 304, 305 and III 304 ). .. 162 4 19 Reactio n progress vs free energy diagram for retro [2+2] cycloaddition. ..... 163 4 20 Nitrile alkyne cross metathesis upon treating 18 with MeCN. ....................... 163 5 1 Amido p orbital aligned with d xy and amido p orbital rotated out of alignment. ................................ ................................ ................................ ..... 185 5 2 Two possible resonance contributions for an enamine and amidoalkylidene. ................................ ................................ ........................... 1 85 5 3 Truncated qualitative orbital diagram of the bonding analogy between enamines 374 and amidoalkylidenes. ................................ .............................. 185 5 4 Push pull synergetic effect of the [CF 3 ONO] 3 pincer type ligand. ............... 186 5 5 Synthesis of 16 ................................ ................................ ............................ 186 5 6 Molecular structure of [CF 3 ONO]W=CH(Et)(O t Bu) ( 16 ) wit h ellipsoids drawn at the 50% probability level ................................ ............................... 186

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20 5 7 Synthesis of 17 ................................ ................................ ............................ 187 5 8 Methyl ation of 17 to form 18 ................................ ................................ ........ 187 5 9 Isobutylene expulsion from 17 to form 19 ................................ .................... 187 5 10 Lewis acid catalyzed isobutylene expulsion fr om 16 to form 20 .................. 188 5 11 Molecular structure of [CF 3 ONO]W(O) n Pr ( 20 ) with ellipsoids dra wn at the 50% probability level ................................ ................................ .................... 188 5 12 Geometry optimized structures for 16 ', 16 Me ', and 17 '. ............................... 189 5 13 The HOMO, HOMO( 1), and HOMO( 2) orbitals of 17' (Isovalue = 0.051687). ................................ ................................ ................................ .... 190 5 14 The HOMO, HOMO( 1), and HOMO( 2) orbitals of 17' ; and the HOMO, HOMO( 1), and HOMO( 2) orbitals of 21' (Isovalue = 0.051687). ................ 191 5 15 Proposed mechanism for isobutylene expulsion from 17 ............................ 192 5 16 Proposed mechanism for isobutylene expulsion from 16 (LA = Me + Me 3 Si + and B(C 6 F 5 ) 3 ................................ ................................ ................... 193 5 17 Truncated X ray structure of 16 and geometry optimized structure 16 Me' illustrating the 77 rotation of the W=C bond. ................................ ............... 193 5 18 The HOMO, HOMO( 1), and HOM O( 5) orbitals of 16 Me' (Isovalue = 0.051687). ................................ ................................ ................................ .... 194 6 1 Proposed alkyne metathesis catalyst featuring a trianionic [pyr ONO] pincer type ligand. ................................ ................................ ........................ 200 6 2 Proposed synthesis of [pyr ONO] pincer type ligand (red arrows) and actual outcome. ................................ ................................ ............................ 200 6 3 Proposed synthesis of [pyr ONO] pincer type ligand (red arrows) and actual outcome. ................................ ................................ ............................ 201 A 1 1 H NMR Spectra of 1 obtained in THF d 8 ................................ .................... 202 A 2 13 C{ 1 H} NMR Spectra of 1 obtained in THF d 8 ................................ .............. 202 A 3 1 H NMR spectrum of 2 in C 6 D 6 ................................ ................................ .... 203 A 4 1 H NMR spectrum of 3 in C 6 D 6 ................................ ................................ .... 204 A 5 1 H NMR spectrum of 4 in C 6 D 6 ................................ ................................ .... 205

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21 A 6 1 H NMR of 5 in C 6 D 6 ................................ ................................ .................... 206 A 7 1 H NMR of 5 dissolved in THF d 8 to form 2 (characteristic p eaks = 8.20, 7.44, 13.23 ppm) and 3 ................................ ................................ .............. 206 A 8 1 H NMR of 6 in C 6 D 6 with 0.01 mL THF d 8 ................................ .................. 207 A 9 1 H NMR of 5 (2.43 x10 5 mol) in C 6 D 6 (red) and with OPPh 3 (5.82 x10 5 ) in C 6 D 6 (blue). ................................ ................................ ................................ .. 207 A 10 Labelling scheme for 1 H and 13 C NMR peaks. ................................ .............. 208 A 11 1 H NMR (CDCl 3, 300 MHz) spectrum of 8 ................................ .................... 212 A 12 Variable Temperature 19 F{ 1 H} NMR (CDCl 3, 300 MHz) spectrum of 8 at 25 C (blue), 35 C (green), 45 C (gray), and 55 C (red) ............................... 212 A 13 13 C{ 1 H} NMR (CDCl 3, 300 MHz) spectrum of 8 ................................ ............ 213 A 14 13 C{ 19 F} NMR (CDCl 3, 300 MHz) spectrum of 8 ................................ ........... 213 A 15 1 H 13 C gHMBC (C 6 D 6, 500 MHz) spectrum of 8 ................................ ........... 214 A 16 1 H 13 C gHMBC (C 6 D 6, 500 MHz) spectrum of 8 expanded. ......................... 214 A 17 1 H 15 N gHMBC (C 6 D 6, 500 MHz) spectrum of 8 ................................ ........... 215 A 18 19 F 13 C gHSQC (C 6 D 6, 500 MHz) spectrum of 8 ................................ .......... 215 A 19 1 H NMR sp ectrum of 9 in C 6 D 6 ................................ ................................ .... 216 A 20 19 F{ 1 H} NMR spectrum of 9 in C 6 D 6 ................................ ............................. 216 A 21 1 H{ 13 C} gHSQC NMR spectrum of 9 in C 6 D 6 ................................ ............... 217 A 22 1 H{ 13 C} gHMBC NMR spectrum of 9 in C 6 D 6 ................................ ............... 217 A 23 1 H{ 15 N} gHMBC NMR spectrum of 9 in C 6 D 6 ................................ ............... 218 A 24 19 F{ 1 H} NMR spectra of 9 in C 6 D 6 (bottom) and with selective decoupling (top). ................................ ................................ ................................ ............. 218 A 25 19 F{ 13 C} gHMBC NMR spectrum of 9 in C 6 D 6 expanded. ............................ 219 A 26 19 F{ 13 C} gHSQC NMR spectrum of 9 in C 6 D 6 expanded. ............................. 219 A 27 19 F{ 13 C} gHSQC NMR spectrum of 9 in C 6 D 6 expanded. ............................. 220 A 28 1 H NMR spectrum of 10 in C 6 D 6 ................................ ................................ .. 220

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22 A 29 19 F{ 1 H} NMR spectrum of 10 in C 6 D 6 ................................ ........................... 221 A 30 31 P{ 1 H} NMR spectrum of 10 in C 6 D 6 ................................ ........................... 221 A 31 1 H{ 13 C} gHSQC NMR spectrum of 10 in C 6 D 6 ................................ ............. 222 A 32 1 H{ 13 C} gHMBC NMR spectrum o f 10 in C 6 D 6 The signals at 278.5 and 16.0 in f1 are 8.5 and 286.0, foled. ................................ ............................... 222 A 33 1 H{ 15 N} gHMBC NMR spectrum of 10 in C 6 D 6 ................................ ............. 223 A 34 19 F{ 1 H} NMR spectra of 10 in C 6 D 6 (bottom) and with selective decoupling (top). ................................ ................................ ................................ ............. 223 A 35 19 F{ 13 C} gHMBC NMR spectrum of 10 in C 6 D 6 expanded. .......................... 224 A 36 1 H NMR spectrum of 11 in C 6 D 6 ................................ ................................ .. 224 A 37 19 F{ 1 H} NMR spectrum of 11 in C 6 D 6 ................................ ........................... 225 A 38 31 P{ 1 H} NMR spectrum of 11 in C 6 D 6 ................................ ........................... 225 A 39 1 H{ 13 C} gHMBC NMR spectrum of 11 in C 6 D 6 ................................ ............. 226 A 40 1 H{ 13 C} gHMBC NMR spectrum of 11 in C 6 D 6 ex panded. ........................... 226 A 41 1 H{ 13 C} gHMBC NMR spectrum of 11 in C 6 D 6 expanded. ........................... 227 A 42 1 H{ 13 C} gHMBC NMR spectrum of 11 in C 6 D 6 expanded ........................... 227 A 43 1 H{ 15 N} gHMBC NMR spectrum of 11 in C 6 D 6 expanded. ........................... 228 A 44 19 F{ 13 C} gHMBC NMR spectrum of 11 in C 6 D 6 expanded. .......................... 228 A 45 19 F{ 13 C} gHSQC NMR spectrum of 11 in C 6 D 6 ................................ ............ 229 A 46 1 H NMR spectrum of 12 in C 6 D 6 ................................ ................................ .. 229 A 47 19 F{ 1 H} NMR spectrum of 12 in C 6 D 6 ................................ ........................... 230 A 48 1 H{ 13 C} gHMBC NMR spectrum of 12 in C 6 D 6 ................................ ............. 230 A 4 9 1 H{ 13 C} gHMBC NMR spectrum of 12 in C 6 D 6 expanded. ........................... 231 A 50 1 H{ 13 C} gHMBC NMR spectrum of 12 in C 6 D 6 expanded. ........................... 231 A 51 1 H{ 1 3 C} gHMBC NMR spectrum of 12 in C 6 D 6 expanded. ........................... 232 A 52 1 H{ 13 C} gHMBC NMR spectrum of 12 in C 6 D 6 expanded. ........................... 232

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23 A 53 1 H{ 15 N} gH MBC NMR spectrum of 12 in C 6 D 6 expanded. ........................... 233 A 54 19 F{ 1 H} NMR spectra of 12 in C 6 D 6 (bottom) and with selective decoupling (top). ................................ ................................ ................................ ............. 233 A 55 19 F{ 13 C} gHMBC NMR spectrum of 12 in C 6 D 6 ................................ ............ 234 A 56 19 F{ 13 C} gHSQC NMR spectrum of 12 in C 6 D 6 ................................ ............ 234 A 57 1 H NMR spect rum of 13 in C 6 D 6 ................................ ................................ .. 235 A 58 19 F{ 1 H} NMR spectrum of 13 in C 6 D 6 ................................ ........................... 235 A 59 13 C{ 1 H} NMR spectrum of 13 in C 6 D 6 ................................ ........................... 236 A 60 1 H{ 13 C} gHMBC NMR spectrum of 13 in C 6 D 6 ................................ ............. 236 A 61 1 H{ 15 N} gHMBC NMR spectrum of 13 in C 6 D 6 ................................ ............. 237 A 62 19 F{ 1 H} NMR spectra of 13 in C 6 D 6 (bottom) and with selective decoupling (top). ................................ ................................ ................................ ............. 237 A 63 1 H NMR spectrum of 14 in C 6 D 6 ................................ ................................ .. 238 A 64 19 F{ 1 H} NMR spectrum of 14 in C 6 D 6 ................................ ........................... 238 A 65 13 C{ 1 H} NMR spectrum of 14 in C 6 D 6 ................................ ........................... 239 A 66 1 H{ 13 C} g HMBC NMR spectrum of 14 in C 6 D 6 ................................ ............. 23 9 A 67 19 F{ 13 C} gHSQC NMR spectrum of 14 in C 6 D 6 ................................ ............ 240 A 68 1 H NMR spectrum of 15 in C 6 D 6 ................................ ................................ .. 240 A 69 19 F{ 1 H} NMR spectrum of 15 in C 6 D 6 ................................ ........................... 241 A 70 13 C{ 1 H} NMR spectrum of 15 in C 6 D 6 ................................ ........................... 241 A 71 1 H{ 13 C} gHMBC NMR spectrum of 15 in C 6 D 6 ................................ ............. 242 A 72 1 H{ 15 N} gHMBC NMR spectrum of 15 in C 6 D 6 ................................ ............. 242 A 73 19 F{ 13 C} gHMBC NMR spectrum of 15 in C 6 D 6 ................................ ............ 243 A 74 19 F{ 13 C} gHSQC NMR spectrum of 15 in C 6 D 6 ................................ ............ 243 A 75 1 H NMR spectrum of 12 in C 6 D 6 and 15 equiv. of MeCN. ( t BuCCMe = 1.54 and 1.20 ppm; 14 = 3.13 and 1.18 ppm). ................................ ..................... 244

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24 A 76 19 F{ 1 H} NMR spectrum of 12 in C 6 D 6 and 15 equiv. of MeCN (blue) along with 19 F{ 1 H} NMR spectr um of 14 (red) ................................ ......................... 244 A 77 Labelling scheme for 1 H and 13 C NMR peaks. ................................ .............. 245 A 78 1 H NMR (C 6 D 6 300 MHz) spectrum of 16 ................................ ................... 248 A 79 19 F{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 16 ................................ ............ 248 A 80 19 F{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 16 with selective decoupling at 73.9 pp m. ................................ ................................ ................................ ..... 249 A 81 13 C{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 16 ................................ ............ 249 A 82 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz) spectrum of 16 expanded. ................. 250 A 83 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz) spectrum of 16 full. ............................ 250 A 84 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded. ....................... 251 A 85 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded. ....................... 251 A 86 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 full. ................................ .. 252 A 87 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded. ....................... 252 A 88 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded. ....................... 253 A 89 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded. ....................... 253 A 90 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 16 ................................ ........ 254 A 91 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded. ...................... 254 A 92 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded. ...................... 255 A 93 19 F 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded. ...................... 255 A 94 1 H NMR (C 6 D 6 300 MHz) spectrum of 17 ................................ ................... 256 A 95 19 F{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 17 ................................ ............ 256 A 96 31 P{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 17 ................................ ............ 257 A 97 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 17 ................................ ......... 257 A 98 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 17 ................................ ........ 258 A 99 1 H 1 3 C gHMBC (C 6 D 6 500 MHz) spectrum of 17 expanded. ....................... 258

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25 A 100 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 17 expanded. ....................... 259 A 101 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 17 expanded. ....................... 259 A 102 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 17 expanded. ....................... 260 A 103 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 17 ................................ ........ 260 A 104 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 17 expanded. ...................... 261 A 105 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 17 expanded. ...................... 261 A 106 19 F 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 17 expanded. ...................... 262 A 107 1 H NMR (C 6 D 6 500 MHz) spectrum of 18 ................................ ................... 262 A 108 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz) spectrum of 18 ................................ ... 263 A 109 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz) spectrum of 18 expanded. ................. 263 A 110 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 18 expanded. ....................... 264 A 111 1 H 13 C gHSQC (C 6 D 6 5 00 MHz) spectrum of 18 expanded. ....................... 264 A 112 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 18 expanded. ....................... 265 A 113 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 18 expanded. ....................... 265 A 114 19 F{ 1 H} NMR (C 6 D 6 500 MHz) spectrum of 18 ................................ ............ 266 A 115 19 F 19 F gDQFCOSY (C 6 D 6 500 MHz) spectrum of 18 ................................ 266 A 116 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 18 expanded. ...................... 267 A 117 19 F 13 C gHSQC (C 6 D 6 500 MHz) s pectrum of 18 expanded. ...................... 267 A 118 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 18 ................................ ........ 268 A 119 1 H NMR (C 6 D 6 500 MHz) spectrum of 19 ................................ ................... 268 A 120 1 H 1 H gDQCOSY (C 6 D 6 500 MHz) spectrum of 19 ................................ ..... 269 A 121 1 H 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. .................. 269 A 122 1 H 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. .................. 270 A 123 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 19 ................................ .... 270 A 124 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. .................. 271

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26 A 125 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. .................. 271 A 126 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. .................. 272 A 127 1 H 15 N gHMBCAD (C 6 D 6 500 MHz) spectrum of 19 expand ed. .................. 272 A 128 19 F{ 1 H} NMR (C 6 D 6 500 MHz) spectrum of 19 ................................ ............ 273 A 129 19 F 19 F gDQCOSY (C 6 D 6 500 MHz) spectrum of 19 ................................ ... 273 A 130 19 F 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. ................. 274 A 131 19 F 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. ................. 274 A 132 19 F 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 19 expanded. ................. 275 A 133 1 H NMR (C 6 D 6 300 MHz) spectrum of 20 ................................ ................... 275 A 134 19 F NMR (C 6 D 6 300 MHz) spectrum of 20 ................................ .................. 276 A 135 13 C{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 20 ................................ ............ 276 A 136 1H 13C gHMBC (C6D6, 500 MHz) spectrum of 20 expanded. .................. 277 A 137 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 20 expanded. ...................... 277 A 138 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 20 expanded. ...................... 278 A 139 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 20 expanded. ...................... 278 A 140 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 20 ................................ ........ 279 A 141 19 F{ 1 H} NMR (C 6 D 6 500 MHz) spectrum of 20 (bottom) and spectra with selective homonuclear de coupling (top). ................................ ...................... 279 A 142 1 H NMR (CDCl 3 500 MHz) spectrum of 22 ................................ .................. 280 A 143 13 C{ 1 H} NMR (CDCl 3 500 MHz) spectrum of 22 ................................ .......... 280 A 144 1 H NMR (CDCl 3 500 MHz) spectrum of 23 ................................ .................. 281 A 145 1 H NMR (CDCl 3 500 MHz) spectrum of 23 ................................ .................. 281 A 146 IR spectrum of 2 (thin film) ................................ ................................ ........... 282 A 147 IR spectrum of 3 (thin film). ................................ ................................ .......... 282 A 148 IR spectr um of 4 (thin film). ................................ ................................ .......... 283 A 149 I R spectrum of 5 (thin film). ................................ ................................ .......... 283

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27 A 150 IR spectrum of 6 (thin film). ................................ ................................ .......... 284 A 151 IR spectrum of 8 (thin film). ................................ ................................ .......... 284 A 152 IR spectrum of 16 (thin film). ................................ ................................ ........ 285 A 153 IR spectrum of 17 (thin film). ................................ ................................ ........ 285 A 154 UV vis spectra of 5 in toluene (1.79 and 8.94 x10 5 M) ................................ 286 A 155 UV vis of 6 in THF (0. 057 mM, red; 0.113 mM, blue). ................................ .. 286 A 156 DART mass spectroscopy spectra of 18 OPPh 3 ................................ ............ 287 A 157 ESI TOF mass spectroscopy spectra o f 8 ................................ ................... 287 A 158 GC CI mass spectroscopy spectra of 22 ................................ ..................... 288 A 159 ESI mass spectroscopy spectra of 23 ................................ ......................... 288 A 160 EPR spectrum of 3 (10 mM solution, toluene) at T = 298 K. ......................... 289 A 161 Individually simulated spectra of an S = 2 (a) and an S = 1.5 (b) systems are added together to get the total spectrum (c) corresponding to the mixture of the dimer (4) and monomer (2) ................................ ................... 289 A 162 Solution EPR of a mixture of 3 and 3a (5.0 x10 3 M) in toluene (blue) and a 3 and 3a solution (1.6 x10 3 M) in toluene (blue) with the addition of 6 equiv. MeCN (red). ................................ ................................ ....................... 290 A 1 63 Cyclic voltammograms of 5 x10 3 M solution of 2 4 and 5 in 0.1 M TBAH/CH 2 Cl 2 at 100 mVs 1 ; glassy carbon working and Ag/Ag + reference electrodes. ................................ ................................ ................................ .... 290 A 164 Molecular structure of 1 Hydro gen atoms are omitted for clarity. ................ 291 A 165 Molecular structure of 2 with ellipsoids drawn at the 50% probability level .. 299 A 166 X ray structure of 3 with ellipsoids drawn at the 50% probability level. ......... 306 A 167 Molecular structure of 4 with ellipsoids d rawn at the 50% probability level .. 311 A 168 X ray structure of 5 ................................ ................................ ...................... 316 A 169 Molecular Structure of 6 ................................ ................................ .............. 323 A 170 Molecular Structure of 12 ................................ ................................ ............ 330 A 171 Molecular Structure of 13 ................................ ................................ ............ 335

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28 A 172 Molecular Structure of 14 ................................ ................................ ............ 341 A 173 Molecular Structure of 15 ................................ ................................ ............ 347 A 174 Molecular Structure of 16 ................................ ................................ ............ 353 A 175 Molecular Structure of 20 ................................ ................................ ............ 358 A 176 Truncated molecular orbital diagram of [CF 3 ONO]W N(OEt 2 ). ................... 368 A 177 Labeling Scheme of the geometry optimization structure for ................. 369 A 178 Guassian optimized IR spectru m for ................................ ...................... 369 A 179 Labelling Scheme of the geometry optimization calculation for 16 ....... 370 A 180 Guassian optimizated IR spe ctrum calculation for 16 ........................... 371 A 181 Labeling Scheme of the geometry optimization calculation for .............. 372 A 182 Guassian opt imizated IR spectrum calculation for ................................ 372 A 183 Labeling Scheme of the geometry optimization calculation for .............. 374 A 184 Guassian optimizated IR spectrum calculation for ................................ 374 A 185 Molecular Orbital Diagram of 16 containing LUMO HOMO( 5). (Isovalue = 0.051687) ................................ ................................ ................. 376 A 186 Molecular Orbital Diagram of containing LUMO HOMO( 5). (Isovalue = 0.051687) ................................ ................................ ................................ 377 A 187 Molecular Orbital Diagram of containing LUMO HOMO( 5). (I sovalue = 0.051687) ................................ ................................ ................................ 378

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29 LIST OF ABBREVIATIONS AU Hartree atomic units C 6 D 6 benzene d 6 C 6 H 6 benzene CF 3 ONO 2,2' (azanediylbis(3 methyl 6,1 phenylene))bis(1,1,1,3,3,3 hexafluoropropan 2 ol) CH 2 Cl 2 Dichlorometha ne CV cyclic voltammetry DFT differential fourier transform DPPH 2,2 diphenyl 1 picrylhydrazyl EPR electron paramagnetic resonance ESI TOF electron spray ionization time of flight Et 2 O diethyl ether FT IR fourier transform infrared g gra m gDQF COSY gradient double quantum filtered COSY gHMBC gradient heteronuclear multiple bond coherence gHMBCAD gradient heteronuclear multiple bond correlation with adiabatic pulse gHSQC gradient heteronuclear single quantum coherence gHSQCAD gr adient heteronuclear single quantum correlation with adiabatic pulse GHz gigahertz h hours

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30 HCl hydrochloric Acid HOMO highest occupied molecular orbital Hz hertz IR infrared K rate constant KCl potassium chloride K eq equilibrium constant k obs observed rate constant Ln natural log LUMO lowest unoccupied molecular orbital M Molar M C metal carbon Me methyl Me 3 SiOTf trimethylsilyl triflate MeCN acetonitrile MeOTf methyl triflate mg milligram min minute mmol millimol MO molecular orbital mol mol MS mass spectrometry NACM nitrile alkyne cross metathesis

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31 n BuLi n butylithium n J coupling constant from n bonds away NMR nuclear magnetic resonance OAT oxygen atom transfer OPPh 3 triphenylphosphine oxide O Tf trifalte P 4 O 10 phosphorus pentoxide Ph phenyl Ph 3 P=CH 2 methylene(triphenyl)phosphorane Ph 3 P CH 3 methyl triphenyl)phospho nium PPh 3 triphenylphosphine R majority spin S spin multiplicity s seconds SOMO singly occupied molecular orbital t t ime t bp trigonal bi pyramidal t Bu tert butyl t BuOCO di tert butyl terphenyl] diol THF tetrahydrofuran TOF turnover frequency TON turnover number UV vis ultraviolet and visible light

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32 WC 3 tungstenabutadiene ring X mo lar ratio enthalpy of activation entropy of activation M icroliter Micromole 1/2 width at half height

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33 Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy DESIGNING TRIANIONIC PINCER AND PINCER TYPE LIGANDS FOR APPLICATIONS IN AEROBIC OXIDATION C H BOND ACTIVATION, A ND ALKYNE METATHESIS By Matthew E. August 2013 Chair: Adam S. Veige Major: C hemistry Trianionic pincer and pincer type ligands are an emerging class of multianionic pincer ligands suited for high oxidation state metals (M n+ n= 3 6). A defining feature of trianionic pincer and pincer type ligands is the rigid meridional coordinat ion geometry, which provides an open metal coordination site trans to the central pincer donor atom that can be exploited for catalysis. These ligands are easily modified though the selection of anionic donor atoms (e.g. C, O, N) and the ligand scaffold de sign As such, each trianionic pincer/pincer type ligand imparts a unique reacti vity to the metal center. In this thesis we explore the unique reactivity imparted by rationally designed trianionic pincer/pincer type ligands to (1) a chromium oxidation cat alyst supported by a [ t BuOCO] ligand and (2) a tungsten alkylidyne featuring an [CF 3 ONO] ligand for the applications of alkyne metathesis and C H bond activation. [ t BuOCO]Cr III (THF) 3 ( 2 ) catalyzes the aerobic oxidation of PPh 3 with an exceptionally high turn over number (TON). A kinetic investigation reveals that complex 2 avoids typical deactivation pathways. Complex 2 becomes more reactive tow ard O 2 activation upon comproportionation with [ t BuOCO]Cr V (O)(THF) ( 3 ), yielding a unique

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34 autocatalytic O 2 activati on mechanism. Probing product inhibition with OPPh 3 the rate of O 2 activation by 2 surprisingly accelerates with higher concentrations of OP Ph 3 The synthesis of an isolable Cr V O and (Cr IV oxo) species presents interesting models to investigate oxygen atom transfer (OAT) reactions to phosphines. We present the first kinetic investigation of OAT directly from a (Cr IV oxo) species and conclude a unique role that the donor ligand play s d uring OAT. A [CF 3 ONO] trianionic pincer type ligand supported tungsten alkylidyne ( 12 ) reacts with alkynes to form exceptionally stable tungstena cyclo butadiene complexes that do not undergo retro [2+2] irreve rsibility, complex 12 was found to be exceptionally destabilized by an unusual orientation of the amido donor within the [CF 3 ONO] trianionic pincer type ligand. The amido lone pair of electrons forms an inorganic version of an enamine within the metal coo Chapter 6, we demonstrate the enhanced nucleophilicty with the tungsten alkylidene ( 16 ) and an anionic tungsten alkylidyne ( 17 ) that activate the C H bond of O t Bu to release isobutylene.

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35 CHAPTER 1 INTRODUCTION INTO TRIANIONIC PINCER AND PINCER TYPE LIGANDS 1.1 Pincer and Pincer Type Ligands Trianionic pincer and pincer type ligands are an emerg ing class of multianionic tridentate ligands inspired from the traditional pincer ligand desig n. 1 The quintessential pincer design developed by Shaw et al. 1 contains an anionic carbon donor between two pendant arms bearing neutral phosphine donor s (Figure 1 1 ), wh ile p incer type ligands replace the central anionic carbon atom donor with an anionic heteratom (Figure 1 1) 2 A defining feature of all pincer and pincer type ligands is their confined meridional coordination geometry of the tridentate ligand Moreover, by virtue of t he simplistic design pincer and pincer type ligands are easily modified for specific applications. Hence, slight c hanges to the pendant arms, the central donor atom, the chelate ring size, and pincer framework allow for fine contr ol over the e lectronic and steric components imparted to the metal fragment 3 These relatively facile modifications make pincer and pincer type ligands a highly versatile ligand platform that can be engineered for specific applications in c atalysis, molecular sensing, switches and materials ; which have been extensively reviewed. 4 26 1.2 Developing Trianionic Pincer and Pincer Type Ligands 1.2 .1 Pincer Ligands for High Oxidation State Metals T raditi onal pincer and pincer type ligands are monoanionic and arguably suited for low oxidation s tate metals. E xpanding the rich chemistry of these ligands to high oxidation state metals ( M n+ n>3) for the purposes of catalysis and exploring fundamental chemical transformations is problematic however A s illustrated in Figure 1 2 a pincer ligated complex may be accompanied by n 1 anionic ligands as well,

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36 producing a coordinat iv ely saturated metal ion ; which can limit the applications especially in catalysis due to the lack o f an open coordination site for the substrate to enter Avoiding a coordinately saturated metal ion requires a modification to the original pincer ligand design. B y incorporating the anionic ligands into the pincer ligand framework, or more c oncisely r onor atoms with anionic donors, t he new t rianionic pincer l igand liberates two additional coordination site s to direct reactants to the metal center ( Figure 1 2 ). 1.2.2 Versatility of the Trianionic Pincer and P incer type Ligand Similar to traditional pincer and pincer type ligands, the trianionic version is an equally versatile ligand platform. Figure 1 3 depicts the current library of demonstrated trianionic pincer 27 43 and pincer type 44 58 ligands presented in the literature. Simple modifications to the ligand design offer an easy approach to control the electronic and steric properties of the ligand Thus, a particular trianio nic pincer /pincer type ligand can be engineered to alter the reactivity at a metal center or to induce completely new reactivity. The result is a multifarious ligand class with each trianionic pincer/pincer type ligand imparting a potential ly novel reacti vity to the metal center. As such, t he rigid meridional tridentate ligand class is ideally suited to explore a wide variety of high valent metal catalysis and chemical transformations. Evidence for their multifarious nature is the diverse applications that now include catalyzed aerobic oxidation 36 alkene isomerization, 28 alkene 27 and alkyne 31, 59 polymerizatio n, nitrene 45, 46 and carbene 51 group transfer, and fundamental transformations such as oxygen atom transfer, 32 nitrogen atom transfer, 60 O 2 activation, 33 C H bond activation, 53 and disulfide reduction. 48

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37 Work in the Veige group focuses on exploring the reactivity imparted to the metal center by each trianionic pincer/pincer type ligand. Our approach has b een two fold. The first is designing trianionic pincer and pincer type ligands that can potentially improve a specific catalysis, and the second is exploratory by examining the reactivity through fundamental transformations. Also contributing in this endea vor is Heyduk and coworkers, 45 52, 55, 58 who are investigating redox active pincer type ligands that feature the trianionic property In achieving our goal to unearth the potential of trianionic pincer and pincer type ligands with high oxidation state metals multiple ligand design s that accentuate novel reactivity at the metal center are needed to explor e a wide variety of chemical transformation. This brief overview provides a glimpse of the (1) different r eacti on s influenced by trianioni c pincer and pincer type ligand design, and (2) current approaches to create reative metal fragments By analyzing the different sub groups of pincer and pincer type ligands, some interesting trends emerge. This introduction will serve to to summarizing current work in this field and be a useful reference for researchers to rationally design trianionic pincer and p incer type ligands for specific applications. As research with trianionic pincer and pincer type ligands continue to e xpand, we are confident that more applications and strategies for creating reactive metal complexes featuring trianionic pincer and pincer type ligand will be appended to the growing list.

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38 1. 3 Rational Approaches to Create Reactive C omplexes Though tria nionic pincer and pincer type ligands are easily modified, t he task of designing a trianionic pincer and pincer type ligand for a specific application can be quite complicated From a simple perspective, the selection of the anionic donor atoms, the chelat e ring size, and steric groups on the pendant arms must be compatible with the desired application. For instance, the steric groups on the pendant arms provide a valuable protection to avoid dimerization or higher order clusters. 30 Here we provide a more informed list on how trianionic pincer and pincer type ligands may influences a 1. Confined me ri dional geometry with early transition metals 2. Restricted bite angle of pincer pendant arms 3. Open coordination site for catalysis 4. Insertion of unsaturated substrate into central pincer M C bond 5. Electronically unsaturated metal centers 6. Constrained donor atom orientation 7. Support high oxidation state to promote inert bond activation 8. Redox active pincer l igands to mediate oxidation/reductions 1. 3 .1 Confined Medional Geometry with Early Transition Metals T raditional pincer ligand s offer lit tle to no disturbance to many late transition More specifically the square p lanar or octahedral geometries which are prolific among late d 6 and d 8 transitions metals n aturally do not experience any significant distortion upon ligating with a meridional tridentate ligand. However, for early transition metal s the coordination ge ometries are more diverse and include tetrahedral, trigonal bipyramidal, square pyramidal, and octahedral geometries For heavier transition metals, 7 and 8 coordinate complexes are not

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39 uncommon. 61 Coordinating a trianionic pincer ligand to early transition metals exert s a preference on the coordination environ ment about the metal For example, the tetrahedral geometry common for Group(IV) m etals (Ti, Zr, and Hf) is obliged to adopt a square planar /seesaw geometr y upon ligating with a trianionic pin ce r/pincer type ligand (Figure 1 4 ). Additionally, similar restrictions on the ligand arrangement can be imagined with 5 and 6 coordinate comple xes The fix ed coordindation geometry provided by a t rianionic pincer/pincer type ligand presents a unique opportunity to investigate the role of ligand fluxionality 62 66 with in high valent metal catalysts During a catalytic cycle, a set of coordinated ligands may exchange positions, dissociate, or adopt different coordination geometries between intermediates. Hemilab i le ligands 67 74 are an exe mplary ligand class with late transitions metals that promote ligand fluxionality to lower the energetic barrier between catalytic intermediates. Thus, employing a rigid meridion al tridentate ligand provides a n informative model to investigate the effect of ligand fluxionality by rest ricting the movement of otherwise freely moving ancillary ligands The simple experiment design directly assesses the role of ligand fluxionality in alter ing the energetic landscape for the transformation between catalytic intermediates, and possibly may l ead to enhance d catalytic results This thesis includes an investigation into alkyne metathesis presented in Chapters 4 and 6 that explores the fluxionality of the ancillary ligand during catalysis. 1. 3 2 Constrained Bi te Angles of Trianionic Pincer L igan ds Controlling the bite angle of the pendant pincer arm s is also a strategy that can be used to generate reactive complexes ideal for catalysis (Figure 1 5 ) Ideally, the pendant donor arms span 180, but the pincer framework may prevent the donor atoms fr om achieving this angle. The constrained bite angle depend s on the linker spacing

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40 within the p incer scaffold and the size of the coordinated metal ion. The bite angle influences both the electronics of the metal center by the angular overlap 75 of atomic orbitals and the steric influence imparted by the pendant arm The b ite angle a nd its conseq uence on catalytic reactivity has been well documented for bis phosphine ligands. 76 84 Notable examples featuring trianionic pincer ligands are the NCN pincer ligated h a fnium complexes developed by Veige and coworkers that exhibit a constrain ed pincer bite angle of ~140 . 29, 30 The considerable difficulty in synthesizing trianionic pincer/pincer type complexes with acute bite angles however has limited the investigation into the ir reactivity. 1. 3 3 Open Coordination Site A significant challenge in cataly sis is to provide a substrate with eas y access to the metal center, especially when a substrate is poorly coordinating or too large to approach the metal center. A key motivation to use trianionic pincer ligands is to provide an unhind ered metal coordinati on site for the substrate to access Figure 1 6 highlights two possible scenarios where a trianionic pincer/pincer type ligand coordination environment. Case A: Trianionic pincer and pincer type ligands confine what would be a trigonal a rrangement of anionic donors (X) into a T shape geometry creating a vacant coordination site. Case B: Replacing a macrocycl ic tetradentate ligand (e.g. salen, porphyrin, and corrole) with a tridentate pincer ligand exposes an additional coordination site a s well Also, t rianionic pincer ligands containing a central metal carbon bond impart a strong trans influence that weakens the potential ligand bonding at the new coordination site, thus enhancing the lability of the trans coordination site

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41 1. 3 4 Inserti on of U n saturated Substrate into Central Pincer M C B ond More specific to the chemistry of OCO trianionic pincer ligands, unsaturated hydrocarbons such as alkynes insert into the pincer carbon metal bond (Figure 1 7) 34, 39 More recently, the V eige group has demonstrated that the C of a tungsten alkylidyne reversibly insert s into a pincer C W bond to form a tetraanionic pincer ligand. 59 The resulting complex display s remarkabl e activity as a catalyst for alkyne polymerization (Figure 1 7 ) 31, 59 1. 3 5 Electronically Unsaturated Metal Centers In addition to the metal center being coordinately unsaturated, tr ianionic pincer and pincer t ype ligands can produce electronically unsaturated metal complexes useful for catalys i s. The low electron count o f early and high valent transition metals induces a n electrophilic metal center Trianionic pincer and pincer type ligands with few donating electrons can serve to starve the metal electronically. A notable example is a t rianionic NCN supported Cr IV methide that is formally a 14 electron complex and an active catalyst for ethylene polymerization. 27 1. 3 6 Constrained Donor Atom Orientation Pincer and pincer type ligand s by nature of their rigid multidentate scaffold can constrain the orientation of a lone pair of electron s on a sp 2 hybridized donor atom (e.g. amido) with respe ct to a metal center (Figure 1 8) For instance, nearly a ll trianionic pincer ligands containing an amido donor (NCN, NNN, ONO,SNS) lock the orientation of the amido lone pair in a specific orientation w ith the metal ion ( Figure 1 3) Hence, the amido lone pair is unable to freely rotate often precluding the most suitable bonding interaction with a metal center. As a result, a bonding combination between the metal

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42 and the N atom lone pair may provide inte resting electronic 50 and geometric 44 consequences that may generate a reactive metal fragment 53, 54 1. 3 7 Support High Oxidation State Metals Trianionic p incer a nd pincer type ligands by nature of the ir basic anionic donors support high oxidation state metals similar to tetradentate porphyrin and corrole ligands 85 88 but only occupy three coordination sites The strongly reducing coordination environment provided by the trianionic ligand facilitates the coordinated metal center (M n+ ) in activating X X multiple bonds such as O 2 or N 2 by stabilizing the resulting high oxidation state metal (M ( n+ m)+ X). However, the challeng e in oxygenase catalysis or dinitrogen functionalization is balancing the electron requirements for activating X X multiple bonds and then mediating X atom transfer to an organic substrate. In contrast to porphyrin and corrole ligand architectures, trianio nic pincer and pincer type ligands are easily modified by selection of pendant donor groups to fine tune the electronic and steric requirements to support high oxidation state metal ions for bond activation processes. 1. 3 8 Redox active Pincer L igands Tri anionic pincer type ligands with conjugation among the three donor sites can undergo multip le oxidation state changes. These are defined as r edox active pincer type ligands As a result of this conjugation, the trianionic pincer type ligand can access a dianionic and mono ani onic oxidation state (Figure 1 9 ) in a similar fashion to catecholate, semiquinolate, and quinone oxidation states. A two electron redox cycle of a trianionic pincer type ligand is a valuable transformation to achieve multiple electron processes at a meta l center. In particular, when a metal center becomes inert to further oxidation, the pincer type ligand may

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43 provide two additional electrons to reduce the substrate within the metal coordination sphere. Essentially, redox active trianionic pincer ligands s erve as an electron reservoir for a metal center and can mediate oxidative and reductive transformation s The research by Alan F. Heyduk 45 52, 55, 58 focus es on incorporating redox chemistry typically associated wi th late transition metals to the highly polarized metal ligand bonds of d 0 transition metals through the use of redox active pincer ligands. Using redox active trianionic pincer ligands are advantageous over traditional bid entate catecholate type ligands. Upon fully oxidiz ing bidentate catecholate type ligands to the quinone form, the neutral ligand weakly coordinates to the metal center and readily dissociat es 46 In constrast, a two electron oxidation of a trianionic pincer type ligand yields a monoanioni c tridentate ligand that does not easily dissociate from the metal center. 1. 4 D esigning Trianionic Pincer and Pincer type Ligands for Applications in Aerobic Ox idation, C H Bond Activation, and Alkyne Metathesis. The work presented here in this thesis serves to demonstrate how trianionic pincer and pincer type ligands can be designed for specific applications Chapters 2 and 4 focus on improving the catalyst design for ae robic oxidation and alkyne metathesis, while Chapters 3 and 5 present an investigation into the fundamental transformations of oxygen atom transfer (OAT) and C H bond activation. The introductions for each chapter highlight the problem s e ncountered in tha t field and how a rationall y designed trianionic pincer/pincer type ligand may contribute to a solution. (Section 1.3). For the chromium based aerobic oxidation catalyst presented in Chapter 2, the appropriate selection of the donor atoms plays a crucial role in directing the metal reactivity. T he trianionic OCO ligand provides the appropriate electronic requirements to

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44 mediate O 2 activation and then transfer the oxygen atom to phosphines. Additionally, by employing a central anionic carbon donor within a fixed meridional tridentate ligand the strong trans influence of the Cr C bond creates a labile/open coordination site that ensures O 2 access to the metal center and avoid s typical catalyst deactivation pathway s Chapter 3 again utilizes the delicate electronic requirements provided by the trianionic OCO pincer ligand to investigate the oxygen atom transfer reaction from high valent chromium oxo complexes Chapter 4 focuses on improving alkyne metathesis catalysts by using a trianionic ONO pincer type ligand. The basic strategy is that the trianionic pincer/pincer type ligands confine the otherwise fluxional ancillary ligands into a T shape geometry and provide s an open coordination site for substrate to enter. As intended, a swift cycloaddition of ste rically large alkynes occurs, but the electronic features of the ONO ligand in addition to the poor steric pressure from the pendant arm prevent a necessary retro [2+2] cycloaddition for further alkyne metathesis from occurring. A unique electronic featur e of the trianionic ONO pincer type ligand is the constrained orientation of an amido lone pair of electrons T he rigid ligand framework constrains the nitrogen lone pair to align col inear ly with the W bond, creating an inorganic version of an enamine In Chapter 5, this unique bonding interaction is used to enhance the nucleophilicity of the W C bond and promote a n un usual C H bond activation via releasing isobutylene

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45 Figure 1 1 The original PCP pincer ligand ( A ) by Shaw, 1 and PNP pincer type ligand ( B ) by Ozerov. 2 Figure 1 2 A coordinately saturated h igh valent metal (M) featuring a pincer ligand A and a low coordinate high valent me tal with a trianionic pincer ligand B

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46 Figure 1 3 Current library of demonstrated tr ianionic pincer A 27 30 B {( t Bu, H), 31 38 ( t Bu, t Bu) 39, 40 ( t Bu, Me), 41, 42 and (Ad, Me) 42 } and C 43 ligands; and pincer type D 44 E { (SiMe 3 H) 44 and ( i Pr,OMe) 45 47 } F 46, 48 52, 58 G 53, 54 H 55 I 56 and J 57 ligands.

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47 Figure 1 4 Coordination geometry changes upon imposing a trianionic pincer ligan d on a tetrahedral metal center. Figure 1 5 Bite angles and linker spacing. Figure 1 6 Creating open coordination sites A) C onfin ing arrangement of dono r ligand B) R eplacing tetradentate macrocycle ligand with tridentate pincer

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48 Figure 1 7 Insertion into the OCO pincer C M bond A) Insertion of unsaturated substrate. B) Insertion of an alkylidyne carbon into OCO pincer C W bond to form a highly active alkyne polymerization catalyst featuring a tetraanionic pincer ligand. Figure 1 8 Constrained amido orientation using trianionic p incer type ligand. Figure 1 9 Potential redox states of a non innocent pincer type ligand.

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49 CHAPTER 2 AEROBIC OXIDATION CATALYST FEATURING BY A TRIANIONIC PINC ER C r III /C r V COUPLE AVOI DING COMMON CATALYST DEACTIVATIO N PATHWAYS 2.1 Introduction The vast majority of oxidation reactions are performed to make commercial chemicals from crude oil 89 91 Even after crude refinement, multiple selective oxidation steps are required to transform the starting materials into useful reagents for further upstream derivation and application. 91 93 Oxidation reactions present a significant challenge and danger to accomp lish on an industrial sca le. 93 The oxidant must be both easily available and powerful while ensuring security Dioxygen, O 2 is an ideal oxidant source due to its atom economy, selectivity, environmental, and monetary considerations. 94, 95 T hough the direct oxidation of organic substrates with O 2 is thermodynam ically favorable the reaction is spin forbidden creating a high kinetic barrier. 96, 97 As result, autooxidation reactions require heating at high temperatures and are inherently unselective. T ransition metal complexes 94, 95, 98 can selective ly mediate several types of oxi d ation reactions using dioxygen as the oxidant source avoiding the high kinetic barrier for the spin forbi dden reaction A simple classification of oxidation reactions are oxidase monooxygenase, and dioxygenase. Oxidase 99 110 reactions oxidize the substrate without i ncorporating oxygen atom into the product, whereas Reprinted/adapted with permission from M. O'Reilly, J. M. Falkowski, V. Ramachandran, M. Pati, K. A. Abboud, N. S. Dalal, T. G. Gray and A. S. Veige, Inorg. Chem. 2009, 48 10901 10903. Copyright 2009 American Chemical Society. Reprinted/adapted with permission from M. E. O'Reilly, T. J. Del Castillo, J. M. Falkowski, V. Ramachandran, M. Pati, M. C. Correia K. A. Abboud, N. S. Dalal, D. E. Richardson and A. S. Veige, J. Am Chem So c. 2011, 133 13661 13673. Copyright 20011 American Chemical Society.

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50 monooxygenase 94, 111 116 and dioxygenase 94, 112, 117 deliver one and both oxygen atoms to the substrate respectively Ho mogeneous transition metal complexes excel at mediating oxygen atom transfer 118 122 and catalyze oxidation reac tions using a mild O atom source, 94, 95, 98 but relatively few utilize molecular oxygen. 98, 117, 123 135 Aerobic oxygen ase catalysts face a unique challenge. 136 The ligand design must appropriately balance the electronic requirements needed by the metal center. A metal catalyst must be reducing enough to activate O 2 yet the resulting metal oxo complex must be sufficiently oxidizing to transfer the O atom to substrate. 137, 138 For practical applications, maximizing the rat e of O 2 cleavage is important, but not at the cost of creating inert metal oxo intermediates. 139 Oxygenase catalysis p resents a second substantial difficulty in addition to the sensitive electronic requirements. The supporting ligand must avoid catalyst deactivation pathways presented in Figure 2 1 Product inhibition is the most salient deactivation mechanism where the oxidized substrate binds to the catalyst to produce a coordinately saturated metal ion. A second deactivation mechanism is the comproportionation of M n+ and M (n+2)+ =O species to yield thermodynamically stable dinuclear oxo complexes that do not partipate in catalytic turnover. 122, 137, 140 142 M O M species are known for iron, 135, 143 15 3 chromium, 141, 154 160 and manganese 142, 161 175 oxidation catalysts. Of that group, formation of (P)Fe III O Fe III (P) (P = porphyrin) 176 per manently deactivate the catalyst 135, 143 145 whereas Cr O Cr and Mn O Mn complexes form reversibly during catalytic turnover. In both cases, the product inhi bition and oxo dimer formation impede the re oxidation of the catalyst by the oxidant

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51 Oxygenase c atalyst s featur ing tetradentate ancillary ligand s (e.g. porphyrin, corrole, and salen) are susceptible to catalyst deactivation by product inhibition. A n exemplary system by Gray and co workers 128 featur es a corrole ligated 85, 177 179 Cr III /Cr V O cycle. This system catalyzes the aerobic oxidation of triphenylphosphine (PPh 3 ), but product inhibition and catalyst decomposition limit the turnover number (TON; mol product/mol catalyst) to 33. Similary, the c atalytic oxidation of thiophenol to diphenylsulfide yields a TON of 55 and a turnover frequency of ~3 h 1 (TOF; mol product/mol catalyst 3 h). Our approach to improve the ove rall catalyst performance is to replace tetradentate ligand s with a tridentate trianionc pincer ligand. Similar to corroles, trianionic pincer ligands can stabilize high oxidation states needed for dioxygen activation, 85 yet only bind three sites. We envisioned that a catalyst containing more open or labile sites will exhibit improved catalytic properties More specifically the trianionic OCO pincer ligand purposely exploit s the Cr C bond trans influence to weaken bonds to the newly created coordination site (Figure 2 2 ). Here, we present the synthesis of an aerobic oxidation catalyst featuring a trianionic OCO 3 pincer ligand supported chromium complex The catalyst d isplay s remarkable activity for the oxidation of PPh 3 Moreover, we conclusively demonstrate that the trianionic pincer ligand avoids typical deactivation pathways enabling remarkably swift O 2 activation. 2.2 Results and Discussion 2.2.1 Synthesis of [ t BuOCO]HK 2 t BuOCO]Cr III (THF) 3 (2) We sought a mild metalation strategy that combines double salt metathesis with C H bond activa tion. Thus, we synthesized the dipotassium derivative [ t BuOCO]HK 2

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52 THF ( 1 ) by treating [ t BuOCO]H 3 with potassium hydride (KH) in THF ( Figure 2 3) Upon the addition of 1 to MeCrCl 2 (THF) 3 in THF, the solution instantly darkens f rom lime green to dark gre en ( Figure 2 4 ). After 5 h, solvent remo val provides a green solid. The product is extracted into toluene, and KCl is removed by filtration. After removing the toluene in vacuo, the residue is dissolved in minimal THF and cooled to 35 C to induce crystal lization and produce analytically pure 2 in 44% yield. The 1 H NMR spectrum of 2 reveals paramagnetically shifted and broadened 1/2 1/ 2 =1035; t Bu), 1/2 =645), 1/2 = 750), and 1 /2 = 2520) ppm. No resonances are observed in the 13 C{ 1 H} NMR spectrum of 2 Although the 1 H NMR spectrum is not useful for confirming the identity of 2 there is enough information available (location of 1/2 ) to determine if subsequent rea ctions lead to new chromium containing products. Single crystals grow by cooling a concentrated solution of 2 in THF to 35 C. Exemplifying the reactivity of 2 toward O 2 crystals of 2 immersed in Paratone 8277 oil (Exxon) darken within minutes and must b e cooled with dry ice prior to crystal selection for X ray analysis. Figure 2 5 depicts the molecular structure of 2 which consists of a distorted octahedral Cr III ion coordinated by the OCO 3 pincer and three THF ligands. The mutually trans THF ligands a nd two lattice THF molecules (not shown) are disordered. The OCO pincer ligand adopts a pseudo C 2 symmetric orientation. A strong trans influence from the Cr C1 bond (d(Cr1 C1)= 2.011(3) ) causes a 0.14 elongation in the Cr1 O3 bond length (d(Cr1 O3) = 2.1939(18) ) compared to Cr1 O4 (d(Cr1 O4) = 2.0624(18) ) and Cr1 O5 (d(Cr1 O5) = 2.0566(18) ). As expected,

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53 shorter bonds form between the Cr III ion and the alkoxide attachments (d(Cr1 O1)=1.9227(17 ) and d(Cr1 O2)=1.9248(17) ). 2.2. 2 Synthesis of [ t When treating 2 with an excess of O 2 (1 atm) in toluene, the Cr V O complex [ t BuOCO]Cr V O ) (THF) ( 3 ) forms immediately ( Figure 2 6 ), and the solution color changes from bright green to red brown. The 1 H NMR spectrum of 3 exhibits severa l broad paramagnetically shifted resonances at 11.4 1/2 = 117 ) 9.0 1/2 = 201 ) 4.3 1/2 = 225 ) 2.4 1/2 = 363 ) and 1.2 1/2 = 45 ) ppm. The addition of THF to the NMR tube causes the signal at 1.2 ppm to grow and is attributable to a bound THF capable of rapid exchange with free THF. In the solid state, 3 is brown, and the Cr V O stretch appears as a strong absorption at 988 cm 1 and shifts to 943 cm 1 for the Cr V 18 O derivative. 36, 57, 180 189 An EPR spectrum (A ppendix ) of a 10 mmol solution of 3 in toluene exhibits a strong resonance at g iso =1.9770. The central absorption corresponds to the S=1/2 electron spin transition from the 52 Cr isotope (I=0) and four weak satellite peaks, spaced 19 G (1.9 mT) apart, aris e from hyperfine splitting with the 53 Cr (I=3/2) nucleus, consistent with a Cr V ion. 190 The UV vis spectrum of 3 reveals ligand to metal charge transfer absorptions in the UV region at 250 nm and at 285 nm and a weak d d transition at 500 nm. Figure 2 7 shows the mole cular structure of the Cr V 3 obtained by single crystal X ray analysis and confirms the presence of an oxo ligand. Complex 3 consists of a Cr V ion in a distorted trigonal bypyramidal (tbp) geometry that consists of the OCO trianionic pincer, the oxo, and a THF molecule in one of the axial positions. The oxo ligand occupies an equatorial position with a typical Cr O bond length of

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54 1.5683(18) 36, 57, 180 189 The C 1 Cr O3 angle of 165.27(8) is significantly distorted from linearit bond. The equatorial atoms create angles of 116.73(9), 115.82(9), and 126.89(8), signifying a coordination geometry closer to tbp than to square pyramidal. This is the first exam ple of a tbp Cr(V) oxo complex. 36, 57, 180 189 Spin unrestricted density functiona l theory calculations were performed on 3 an analogue of 3 having methyl groups in place of t butyl. Full geometry optimization c onverged on a potential energy minimum, as confirmed by a harmonic vibrational frequency calculation. The optimized structure captures the trigonal bipyramidal geometry about chromium. The computed bond distances agree well with crystallographic values: th e calculated (experimental) chromium ox o oxygen bond length is 1.569 (1.5683(18) ); the Cr O pincer distances are 1.819 (1.8166(17) ) and 1.815 (1.8098(17) ), and that to the THF oxygen atom is 2.243 (2.1781(17) ). The calculated Cr C pincer bond length is 1.992 (2.009(2) experimental). The calculated g factor agrees well with the experimental data (1.9970 exptl/1.969 calcd). The short distance between chromium and the oxo ligand suggests multiple bond character, and the Wiberg bond order is 2.15. 19 1 Corresponding Cr O bond orders to the pincer ligand oxygen atoms are 1.00 and 1.04. The THF ligand is weakly held, with a Cr O bond order of 0.27. The unpaired electron (S=1/2) resides in an orbital of mixed Cr pincer ligand parentage ( Figure 2 8) The highest occupied and lowest unoccupied Kohn Sham orbitals are majority spin (R) functions. A Mulliken population analysis 192 assigns 21% of the R HOMO (HOMO = highest occupied molecular orbital) density to Cr and 79% to

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55 the anionic pincer. The R LUMO (LUMO=lowest unoccupied molecular orbital) is primaril y a Cr THF character. The Cr nucleophiles such as PPh 3 2.2.3 Aerobic Oxidation of PPh 3 C atalyzed by [ t 2 ) Indee d, in the presence of 1 atm of O 2 the reduced Cr III complex 2 catalytically oxidizes PPh 3 to O=PPh 3 with a TON of 195 ( Figure 2 9 ) The catalysis works on a bulk scale. Within 3 h, 0.68 g of O=PPh 3 (2.44 mmol) fo rms with only 8 mg (0.0125 mmol) of the catalyst. In an NMR tube reaction, consumption of 10 equiv of PPh 3 occurs before obtaining the first spectrum ( 5 min), which correlates to a minimum turnover frequency of 100 h 1 In the presence of excess O 2 after consumption of all of the PPh 3 the red brown color of the Cr V O persists, but upon reintroduction of more substrate, the catalysis resumes. Catalytic turnover with 2 also occurs when air is the source of O 2 To confirm a dioxygenase model, treating 2 with a stoichiometric amount of 18 O 2 and PPh 3 provides >98% 18 3 quantitatively. During the catalytic reaction, a broad resonance appears in the 31 P{ 1 H} NMR spectrum at 26.18 ppm, and as more product 3 at 30.11 ppm, This is attributable to a phosphineoxide bound Cr III 3 2 .2. 4 Prelude to the Kinetic Investiga tion into the M echanism O 2 Activation by 2 The trianionic OCO pincer ligand creates a sufficiently reducing environment within complex 2 that is needed to activate O 2 to form a high oxidation state Cr V complex. Complex 3 is thermodynamically competent to transfer the oxo ligand to PPh 3 but is unable to transfer the oxygen atom to other substrate s, such as sulfides and

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56 olefins. The catalytic aerobic ox ida tion of PPh 3 by complex 2 is impressive (TON =195) relative to the corrole system (TON = 33), suggesti ng that the additional pincer ligand may be responsible. However, a complete kinet ic investigation is required to probe the mechanism of O 2 activation and possible catalyst deactivation pathways that would inhibit reoxidation of the catalyst. P resented in the next section is that study. 2 .2. 5 UV vis Measurements for the Rate of O 2 Activation by 2 A color change from green to reddish brown occurs when 2 reacts with O 2 to form the Cr V (O) complex [ t Bu OCO]Cr V (O)(THF) ( 3 ). UV visible spectrophotometry is a suita ble method for studying the reaction of [ t Bu OCO]Cr III (THF) 3 ( 2 ) with O 2 Figure 2 10 depicts the time dependent changes in absorption upon exposure of a 1 x10 4 M solution of 1 to 1.66 x10 3 M O 2 Control ling the O 2 concentration requires injection of a k nown quantity of an O 2 saturated THF solution (9.90 x10 3 M at 25 C). 193 Changes in the UV vis spectrum displays isosb estic points at 318 and 385 nm, and measuring the changes in the absorption at 341 nm generates a plot of the concentration of 2 vs time ( Figure 2 11 ). The complete oxidation of 2 occurs within approximately three minutes. Plots of concentration vs time r eveal a linear segment within the first ~80% of the reaction, followed by a gradual curvature in the remainder of the reaction until completion ( Figure 2 11 ). The plot of [ 2 ] vs time does not fit first order or second order kinetics. 2 .2. 6 O 2 C leavage R ate D ependence on [2], [O 2 ], [THF], and T emperature Solutions of 2 between 0.55 1.65 ( x10 4 ) M, were allowed to react with a known quantity of O 2 to produce the concentration versus time plots in Figure 2 12 The initial rates can be determined from the in itial values of [ 2 ]/ t. Figure 2 13 shows the

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57 linear dependence of the average rate, [ 2 ]/ t, on the [ 2 ]. The linear plot indicates a first order dependence in [ 2 ]. Determination of the order in O 2 requires addition of known quantities of O 2 saturated TH F solutions to 2 The concentration of O 2 in a saturated THF solution is 9.90 x10 3 M. 193 Four independent reactions th at vary in O 2 concentration from 1.66 to 6.66 mM ( Figure 2 14 ) result in a linear plot of initial rate [ 2 ]/ t versus [O 2 ] ( Figure 2 15 ). The linear dependence indicates a first order O 2 relationship. The oxidation of 2 with O 2 in non coordinating solvents proceeds rapidly. The complete oxidation of 2 in hexanes occurs within ~3 s, thus preventing the mea surement of a reliable reaction rate. Introduction of THF between 50% and 100% (v/v) into a hexanes solution of 2 slows the reaction enough to permit the determination of [ 2 ]/ t, and thus the solvents role. Plotting the [ 2 ]/ t vs X THF yields a parabol ic curve ( Figure 3 16 ) consistent with an inverse order in [THF], but the changes in the dielectric constant of the solvent mixture could produce a similar effect. Most likely, the parabolic relation between [ 2 ]/ t vs THF results from the mechanistic di ssociation of one or two THF molecules in addition to dielectric constant changes. Lowering the temperature of the reaction provides more insight into the unusual non first order kinetic profile by resolving the shape of the decay plot of [ 2 ] vs time. Figu re 2 17 depicts the [ 2 ] vs time plot at 40, 20, 10, and 0 C. The kinetic trial at 0 C yields a sigmoidal plot of [ 2 ] vs time, which is consistent with an autocatalytic mechanism. If the oxidation of 2 is catalyzed by 3 then increasing the initial [ 3 ] should accelerate O 2 activation. Figure 3 18 and Figure 3 19 depict an increasing rate of

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58 oxidation of 2 with an increasing initial [ 3 ] and confirms the product catalyzed oxidation of 2 We propose that the oxidation of 1 by O 2 occurs via an autocatalyt ic mechanism. Initially, the oxidation of 1 to 2 is slow. However, upon accumulation of 2 in solution, a faster autocatalytic pathway, in which the product 2 catalyzes the oxidation of 1 to 2 becomes predominant (vide infra). 2 .2. 7 Characterization of the A utocatalytic I ntermediate: the C hromium(IV) oxo D imer {[ t BuOCO]Cr IV (THF)} 2 ( O) ( 4 ) How does [ t BuOCO]Cr(O)(THF) ( 3 ) catalyze O 2 activation by 2 ? One possibility is the formation of a Cr IV O Cr IV adduct that reacts more rapidly than 2 with O 2 An attem pt to form the adduct by stoichiometric addition of 3 to 2 in THF failed. Adding a green solution of 2 and a red solution of 3 in THF yields a brown solution. The 1 H NMR spectrum of the reaction mixture reveals only signals attributable to 2 and 3 and at 35 C, only green crystals of 2 precipitate. When 2 is oxidized to 3 in toluene, however, a bright purple intermediate species forms and then converts to the deep red color of 3 Considering this observation, stoichiometric addition of 2 to 3 in toluene indeed yields a bright purple solution consisting of a small concentration of starting reagents and the major product, postulated to be the dimer {[ t BuOCO]Cr IV (THF)} 2 ( O) ( 4 ) ( Figure 2 20 ). The 1 H NMR spectrum of the reaction mixture (C 6 D 6 ) contains new p aramagnetic resonances distinct from 2 and 3 at 28.70 ( 1/2 = 570 Hz) 16.89 ( 1/2 = 675 Hz) and 30.57 ( 1/2 = 540 Hz) ppm. The characteristic 1 H NMR signals for 4 disappear upon addition of THF indicating an equilibrium exists between Cr III ( 2 ) and Cr V ( O) ( 3 ) and 4 The formation of 4 evidently requires a non coordinating solvent.

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59 Purple hexagonal plate single crystals of 4 form at 35 C from concentrated diethyl ether solutions of the mixture. Since 2 is present in the equilibrium mixture, several cry stals of 2 also deposit, as a result isolation of pure 4 except as a single crystal is not possible. Subjecting the purple crystals to a single crystal X ray analysis experiment provides the molecular structure of 4 In the solid state, complex 4 is C 2 sy mmetric and contains two [ t BuOCO]Cr fragme nts bridged by oxygen ( Figure 2 21 ). The asymmetric unit consists of one half of the molecule and the O atom resides on a C 2 axis that generates the second half of the molecule, thus rendering the Cr ions equidista nt from the oxo by 1.7497(6) and creates a 158.69(14) Cr O Cr angle across the bridge. As a consequence, the Cr O bond lengths do not provide insight to ascertain the Cr oxidation state. The geometry of the Cr IV ion is distorted trigonal bipyramidal ( 194 Each Cr coordinates to a trianionic OCO 3 pincer, the oxo bridge, and a THF molecule. T he equatorial sites consist of the alkoxide attachments, and the oxo bridge, whereas the Cr C pincer bond and THF occupy axial positions. Consistent with a higher oxidation state Cr IV ion, the Cr O pincer (d(Cr1 O pincer ) avg = 1.8046(2) ) bonds are short er than in 2 by 0.113(3) and the Cr C pincer (d(Cr1 C1) = 1.983(2) ) is shorter by 0.028(4) . An interesting structural feature is the ~82 twist between the two Cr ion coordination environments. Figure 12 provides an electronic argument for the appr oximate 90 twist and the near linearity of the Cr O Cr bonds. The sp hybridized oxygen forms two bonds between the Cr ions. The additional four electrons on oxygen donate i nto Cr d orbitals. From Figure 2 22 assigning the C pincer Cr THF as the z axis and Cr O Cr as the x axis, the d xz and d xy are two available d orbitals with appropriate

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60 symmetry for accepting electrons from oxygen. Since the d xy orbital participates in bonding with the two alkoxide ligands, it is high in energy and relatively inaccessible. In contrast, the d xz orbital is a low lying energy orbital available for bonding with o xygen. The most favorable donating interaction is into the d xz of each respective Cr ion, thus adopting a ~90 twist to accommodate the two orthogonal lone pairs on the oxygen. Figure 12 also depicts a ligand field splitting diagram that corresponds to this bonding and electronic interaction. A ssigning two d electrons to the d xz and d yz orbitals of each Cr center allows for the maximum number of unpaired electrons. A similar assignment was made for an isoelectronic V III O V III dimer. 195 The resulting d 2 configuration for each Cr ion supports an oxidation state of +4 for each ion. Despite the smaller Cr IV ion, the Cr THF distance is 0.043(2) longer than that in 2 due to the stronger trans influence of the Cr C p incer bond in 4 and a more congested coordination sphere due to the mutually adjacent [ t BuOCO]Cr IV fragment. 2 .2. 8 Electron Paramagnetic Resonance Measurements of 4 Though the above X ray and NMR results indicated that 4 is a new paramagnetic Cr O Cr dim er, additional data were needed to directly characterize its electronic structure. Figure 2 23 depicts the 240 GHz EPR spectra of a powder sample of 4 The resonances indicate the presence of Cr(III) (weak signals) and a S = 2 dimer ( 4 ). Reducing the te mperature lowers the thermal Boltzmann population of electronic states, and the resonances intensify. The program SPIN 1 96 simulates the EPR spectrum at 4.5 K and, for comparison, Figure 2 24 depicts both the simulated spectrum and experimental data. Simulating the Cr IV O Cr IV species alone did not reproduce all the resonances. Considering that 5 is in equilibrium with the mononuclear complexes 2 and 3 (Scheme 3), complex 4 was included in the simulation. However, complex 3 is difficult

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6 1 to distinguish among resonances 5, 6, and 7 of Figure 2 24 The approximate amount of complex 3 is less than 10% and therefore is not i ncluded in the simulation. The resonances arise from the predominant (~70 %) S = 2 (Cr IV O Cr IV 4 ) and the minor component S = 1.5 (Cr III 2 ) For the dinuclear complex 4 the two paramagnetic fragments, with spins S 1 and S 2 can be described by the fol lowing standard Spin Hamiltonian (Equation 2 1 ), 197 199 H = H hyp ( 2 1) where J is the spin is the La nde g tensor, S is the total spin = S 1 + S 2; with components S x S y and S z with z being taken to be the direction along which the Zeeman field H is applied. H hyp is the electron nuclear hyperfine interaction. The EPR spectrum reveals no hyperfine splittin g from the 53 Cr isotope (9.5% abundant) with I = 3/2, so H hyp can be omitted The Spin Hamiltonian parameters for S = 2 (Cr IV O Cr IV ) are g iso = 1.976, D =2400 G (Gauss), and E = 750 G; and for S = 1.5 (Cr III ) are g iso = 1.976, D =10500 G (Gauss), and E = 3000 G (Figure 14). The good fit of the simulation to the experimental spectrum permits conclusive assignment of a +4 (d 2 ) oxidation state for each Cr ion in 4 The individual simulations for the Cr IV O Cr IV dimer and Cr III species are in the Appendix Figure 2 25 depicts a simulated 240 GHz energy level diagram of 2 (top panel) and 4 (bottom panel) at 4.5 K. The vertical red bars mark the possible spin transitions while the dotted lines point to the relevant peaks corresponding to molecular z orientatio n (z 1 and z 1 2 and z 2 asterisks denote the spin forbidden transitions.

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62 2 .2. 9 Proposed Mechanism of O 2 Activation The reaction orders in [ 2 ], [O 2 ], [ 3 ] and [THF] are consistent with the proposed mechanism i n Figure 2 26 During the initial stages of the reaction, the oxidation of 2 follows pathway A. The first step involves the dissociation of THF followed by O 2 coordination to generate an intermediate species 2 b A single crystal X ray structural analysis o f 2 suggests preferential dissociation of the THF trans to the Cr C pincer bond. Inspection of the three Cr THF bond lengths in 2 reveals the Cr THF trans (Cr1 O3 = 2.1939(18) ) is ~ 0.14 longer than the two Cr THF cis bonds (Cr1 O4 = 2.0624(18) and Cr1 O5 = 2.0566(18) ). It is proposed that intermediate species 2 b then reacts with 2 to generate a second intermediate 2 c before the O O bond cleaves in the final step to yield 3 The first order dependence on [ 2 ] suggests the formation of 2 b is the rate determining step. The high rate of oxidation precludes definitive assignment for the structure of intermediates 2 b and 2 c There are precedents for both end on and side on dioxygen chromium complexes. 200 213 To be autocatalytic, a product catalyzed pathway has to accelerate the formation of 2 b to increase the overall rate of the oxidation. Pathway B in Figure 2 26 illustrates the product catalyzed oxidation o f 2 The formation of dimer 4 from 3 and 2 provides a low coordinate species that allows O 2 access to the metal. The coordination of O 2 to 5 results in the cleavage of the dimer to yield 2 b and regenerates 3 which can re enter Pathway B. Pathway B is fas ter than pathway A because pathway A requires the slow dissociation of THF prior to O 2 coordination thus, autocatalytic conditions establish as the concentration of 3 increases.

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63 2 .2. 10 Kinetic Simulations Strong evidence exists for the autocatalytic path way B; for example, the shape of the decay plots for the oxidation of 2 and foremost, the isolation and characterization of dimer 4 However, during the oxidation of 2 dimer 4 is a steady state intermediate and no experiment directly probes its formation To complement the kinetic studies and to support the proposed mechanism, numerical simulations were performed using the computer program Kinetica. Equation 2 2 describes the stoichiometric reaction between 2 and O 2 to provide 3 and E quations 2 3 to 2 7 show the elementary reaction steps from the proposed mechanism used in the simulations. (2 2) (2 3) (2 4) (2 5) (2 6) (2 7) The elementary steps involving the addition or dissociation of THF are excluded from the simulation. Since [O 2 ] is in ten fold excess, k 1 [O 2 ] and k 5 [O 2 ] are pseudo first order rate constants.

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64 (2 8 ) Equation 2 8 is the derived rate law for the set of E quations 2 (3 7) and the proposed mechanism in Figure 2 26 At each concentration of 2 ( 0.55, 1.10, and 1.65 (x10 4 ) M ) and O 2 (1.66, 3.3 3, 4.99, and 6.66 (x10 3 ) M), three independent concentration versus time profiles were recorded. Using average concentration versus time data from the kinetic trials at each initial [ 2 ] and [O 2 ], the c onjugate gradient optimization provides the best fit r ate constants. The rate constants k 2 and k 3 rate constants are indeterminable since they occur after the rate determining step, and their values were fixed > 1.00 x10 6 The averaged estimated rate constants (k 1 k 4 k 4 /k 5 ) are 2.6( 0.6) s 1 396.8( 0. 7) M 1 s 1 and 6.0( 2.3 ) x10 3 respectively (THF, 25C). Data fitting only permits the calculation of k 4 /k 5 as a ratio for the proposed mechanism. The rate constants were used to simulate individual concentration versus time profiles for kinetic runs that vary in the initial concentration of 2 and O 2 Figure 2 27 and Figure 2 28 illustrate the simulated kinetic profile, and the experimental data, for concentration versus time profiles of 2 at different initial concentrations of 2 and O 2 The simulated kinet ic profiles match the profiles obtained experimentally. For the kinetic profiles varying in temperature, new rate constants were calculated for each temperature and are presented in Table 2 1. Figure 2 29 depicts the simulated and experimental concentrati on versus time profile for the oxidation of 2 with O 2 at different temperatures. An important feature exhibited in this set of data is the curvature of the profile at early reaction times. In particular, at 0 C the reaction slows enough to detect the ons et of the autocatalytic pathway B. The simulated data fits the

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65 experimental data well during this stage of the reaction. At 40 C, the reaction is too fast (only three data points within 10 sec, >90 % conversion) to obtain reliable data. 2 .2. 11 Product I nhibition Studies Product inhibition occurs when a strong coordinating ligand/product binds to the metal center preventing further O 2 activation. In the case of Cr corroles, the product OPPh 3 binds to the two axial positions thus inhibiting further oxidati on. 128 To probe a similar deaction pathway for complex 2 the rate of O 2 activation was measured with increasing [OPPh 3 ]. With higher concentration of OPPh 3 the rate of O 2 activation is expected to decelerate or stop completely. Uniquely for the trianionic pincer complex 2 the opposite occurs; an increasing concentration of OPPh 3 accelerates O 2 activation. Figure 2 30 contains a plot of the change in concentration of 2 versus time during the O 2 oxidation in the presence varying [OPPh 3 ] (0 to 0.1 0 M). The rate of oxidation of 2 accelerates upon addition of OPPh 3 and at 1000 equivalents of OPPh 3 (0.10 M) the rate cannot be measured within our experimental setup. 2.2.12 Isolation of a C atalytic I ntermediate [ t BuOCO]Cr(OPPh 3 ) 2 ( 5 ) The unusual r ate a cceleration caused by the addition of OPPh 3 prompts us to isolate the reactive species prior to the addition of O 2 Treating a solution of 2 with five fold excess OPPh 3 forms a deep green solution ( Figure 2 31 ) Single crystals of the resulting complex fo rm in supersaturated CH 2 Cl 2 solutions, and an X ray analysis provides the molecular structure of complex 5 ( Figure 2 32 ) Complex [ t BuOCO]Cr III (OPPh 3 ) 2 ( 5 ) is square pyramidal with C 2v symmetry in which the pincer carbon atom is apical and the two Cr O alk oxides and O=PPh 3 fulfill the basal positions. The pyramidal base is distorted along the trans O=PPh 3 ligands ( O3 Cr O4 = 157.38(5)) but nearly linear across the trans alkoxides ( O1 Cr O2 =

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66 175.28(5)). The defining feature of 5 is the open coordination site opposite the Cr C1 bond. Consequently, of the three compounds within this study, 5 presents the shortest Cr C pincer bond of 1.9761(17) . Hence, the pincer architecture exploits the strong trans effect of the chromium carbon bond to a labile coordina tion site. By weakening possible dative bonding interaction c omplex 5 obviates catalyst deactivation by product inhibition and provides an accessible binding site for O 2 to facilitate activation. The role of OPPh 3 in facilitating O 2 activation by 2 is si milar to the role of complex 3 in the formation of the dimer 4 Excess OPPh 3 provides the coordinatively unsaturated complex [ t BuOCO]Cr III (OPPh 3 ) 2 ( 5 ) (Scheme 5). The solid state structure 36 indicates only two OPPh 3 ligands coordinating to the Cr III ion despite excess OPPh 3 being present in solution. Complex 5 provides an unobstructed coordination site for O 2 coordination allowing for faster oxidation. The inc reased rate of O 2 activation by adding OPPh 3 suggests an equilibrium between 2 and 5 exists in THF. As more OPPh 3 is added, the equilibrium shifts towards 5 until it is the dominant species. Attempts to directly monitor the rate of O 2 activation with 5 fa iled because the reaction is too fast. 2.2.13 Cyclic V oltametry of 2, 4, and 5 Both dimer 4 and complex 5 have an open coordination site compared to 2 As a consequence, the rate of O 2 activation is faster for 4 and 5 However, the increased oxidation r ate may be a consequence of a more reducing metal ion caused by the coordination of 3 in the dimer 4 and OPPh 3 in complex 5 To examine this possibility, complexes 2 4 and 5 were subjected to cyclic voltammetry experiments to determine their electrode p otentials. Complexes 2 4 and 5 display irreversible first oxidation peaks at 0.732 V, 0.298 V, and 0.012 V respectively. Though the lower oxidation

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67 potentials appear to correlate with the faster rate of O 2 activation, the irreversibility of the CV spectr a prevents a definitive conclusion from being drawn. 2 .3 Conclusions The trianionic OCO pincer ligand offers a balanced electronic environment for oxygenase catalysis. Consistent with our initial presumption, trianio nic pincer ligands support high oxidati on state metals. This is most evident in the activation of O 2 to form complex 3 Additionally, the NCN trianionic pincer chro mium(III) complex activates dioxygen. 28 Yet, the trianionic OCO ligand is not too reducing, or the resulting Cr V is not too stabilized to prevent OAT to PPh 3 as in the case of [NCN]Cr V 28 However, the inability of complex 2 to aerobically oxidize sulfides and olefins illustrate s t he deli cate balance and further work to fine tune the electronic properties is needed to expand the substrate scope Even so, complex 2 is a suitable model system to understand the advantages that a trianionic pincer ligand can bring to oxygenase catalysis. Tr ianionic pincer ligands offer two distinct advantage s over traditional me ridional tetradentate ligands. Catalysts supported by me ridional tetradentate ligands are susceptible to deactivation pathways as product inhibition and O dimerization. Here, we a re able to demonstrate that complex 2 featuring a trianionic OCO pincer ligand 5 ) or formation of oxo dimers ( 4 ) ( Figure 2 33). Rather coordinating the oxidiz ed substrate (OPPh 3 ) to 2 or formation of ox o dimers renders the metal center more reactive towards O 2 Supporting this claim, the kinetic results for the oxidation of 2 reveal an unprecedented autocatalytic mechanism where product 3 accelerat es O 2 activation by forming a oxo dimer, c omplex 4 W e now also co nclude that M O M species can

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68 directly react with oxidant. 214, 215 Additionally, complex 4 is the first crystallographically characterized dinuclear Cr IV O Cr IV complex and the EPR data (peak postiions and the g, D, and E parameters) provides a characteristic fingerprint to identify d 2 d 2 Cr IV O Cr IV species that may enhance other research ers seeking to identify the presence of (Cr IV ) 2 ( O) in their catalytic systems. Simulating conditions for product inhibition OPPh 3 was added to the kinetic oxidation trials and was found to increases the rate of O 2 activation by 2 To further understand the role of OPPh 3 in facilitating O 2 activation by 2 excess OPPh 3 was added to 2 which yielded 5 The single crystal X ray structure of 5 reveals a square pyramidal geometry consisting of two OPPh 3 ligands, one above and one below the plane of the t BuOCO 3 pincer ligand. 36 C omplex 5 is more reactive towards O 2 than complex 2 due to the open coordination site trans to the Cr C pincer bond, which affords O 2 easier access to the metal center. This result clearl y illustrates the advantage of trianionic pincer ligand design. B y occupying only three coordination sites the fourth coordination site trans to the central carbon donor becomes kinetically labile allowing oxidant (O 2 ) continued access and avoids product inhibition 2.4 Experimental Section 2.4.1 General Considerations Unless specified otherwise, all manipulations were preformed under an inert atmosphere using standard Schlenk or glovebox techniques. Pentane, hexanes, toluene, diethyl ether (Et 2 O), tetr ahydrofuran (THF), and 1,2 dimethoxyethane (DME) were dried using a GlassContour drying column. Benzene d 6 (Cambridge Isotopes) was dried over sodium benzophenone ketyl, distilled or vacuum transferred, and stored over

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69 4 molecular sieves. CrCl 2 Me(THF) 3 w as prepared according to published procedures. 216 All other reagents were purchased from commercial vendors and used without further purification. 2.4.2 Analytical Techniques NMR Techniques: NMR spectra were obtained on, Varian Gemini 300 MHz, Varian Mercury Broad Band 300 MHz, or Varian Mercury 300 MHz spectrometers. Chemical shifts are reported in (ppm). For 1 H and 13 C{ 1 H} NMR spectra, the solvent peak was referenced as an internal reference. IR Tec hniques: Infrared spectra were obtained on a Thermo scientific Nicolet 6700 FT IR. Spectra of solids were measured as KBr discs. EPR Techniques: (Vasanth Ramachandran, Mekhala Pati, and Naresh S. Dalal) EPR measurements were conducted using a Bruker Elex sys 500 Spectrometer, at the X band, microwave frequency ~9.4 GHz in the temperature range of 4 to 300 K. The microwave frequency was measured with a built in digital counter and the magnetic field was calibrated using 2,2 diphenyl 1 picrylhydrazyl (DPPH; g = 2.0037). The temperature was controlled using an Oxford Instruments cryostat, to accuracy within 0.1 K. Modulation amplitude and microwave power were optimized for high signal to noise ratio and narrow peaks. Elemental Analysis: Combustion analyses we re performed at Complete Analysis Laboratory Inc., Parsippany, New Jersey. UV Vis Techniques: UV vis spectra were acquired on a Hewlett Packard 8453 spectrometer and variable temperature was maintained using Fisher Scientific Isotemp 10065.

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70 Electrochemi cal Cyclic Voltammograms Techniques: (Marie C.Correia) Electrochemical experiments were performed at ambient temperature in a glove box using an EG&G PAR model 263A potentiostat/galvanostat and a three compartment H cell separated by a medium porosity sint ered glass frit. Electrolytic solutions consisted of 0.1 M tetrabutylammonium hexafluorophosphate (TBAH) dissolved in either CH 2 Cl 2 or THF. Cyclic voltammograms (CV) were recorded at 100 mVs 1 in 4 mL electrolytic solution with 5 x10 3 M complex concentr ation. A glassy carbon electrode (3 mm diameter) was used as the working electrode and a platinum flag as the counter electrode. All potentials are reported versus SCE and referenced to Ag/Ag + The reference electrode consisted of a silver wire immersed in a freshly prepared acetonitrile solution of 0.01 M AgNO 3 and 0.1 M TBAH encased in a 75 mm glass tube with a fitted Vycor tip. The E o values for the Fc + /Fc couple in CH 2 Cl 2 and THF were +0.47 V and +0.58 V versus SCE respectively. 217 2.4.3 Calculations (Thomas G. Gray) Spin unrestricted density functional theory computations were executed in Gaussisn03. 218 functional 219 along with the correlation functional of Perdew. 220, 221 Full geometry optimization was carried out using the standard 6 31G(d,p) basis set 222 224 on all atoms; a harmonic vibrational frequency calculation returned all real frequencies and confirmed the converged structure to be a local minimum of the potential energy hypersurface. Frequencies were calculated analytically. A single point c alculation on the optimized structure was run using the TZVP basis set of Godbelt, Andzelm, and collaborators. 225 Percentage co mpositions of molecular orbitals, overlap populations, and bond orders between fragments were calculated using the AOMix program. 226, 227 The g tensor was

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71 calculated using gauge invariant atomic orbitals (GIAO). 228, 229 All calculations are gas phase. 2.4.4 Synthesis of [ t BuOCO]K 2 (1) (Joseph M. Falkowski) In a nitrogen filled glovebox, 597 mg (1.59 mmol) of [ t BuOCO]H 3 was dissolved in 5 mL of THF. In a separate vial 128 mg (2.01 eq, 3.20 mmol) of potassium hydride was suspended in 2 mL of THF. The solution containing [ t BuOC O]H 3 was added to the potassium hydride suspension and stirred vigorously at room temperature for 4 h. The solution was then filtered and all volatiles removed in vacuo to provide a colorless oil. The oil was triturated with pentane (3 x 1 ml) to yield 1 a s a white powder (705 mg, 75%). 1 H NMR (300 MHz, THF d 8 H ), 7.28 ppm (t, 3 J = 7.79 Hz, 1 H, Ar H ), 6.96 ppm (dd, 3 J = 7.33 Hz, 4 J = 1.83 Hz, 2H, Ar H ), 6.89 ppm (dd, 3 J= 7.79 Hz, 4J = 2.29 Hz, 2H, H8,8 ), 6.86 ppm (dd, 3J = 7.33 Hz, 4J = 2.29 Hz, 2H, H 6 ,6 ), 5.99 ppm (dd, J = 37.33, 3J = 7.33 Hz, 2H, H7,7 ), 1.45 ppm (s, 18H, H12,12 ). 13C{1H} NMR (75 MHz, THF d8, ): 169.6 ppm (C10,10 ), 144.7 ppm(C2,2 ), 137.2 ppm (C9,9 ), 134.5 ppm (C1), 132.19 ppm (C5,5 ), 128.55 ppm (C4), 128.07 ppm (C6,6 ), 126.43 ppm (C3,3 ), 125.67 ppm (C8,8 ), 10 8.17 ppm (C7,7 ), 35.79ppm (C11,11 ), 30.75 ppm (C12,12 ). Anal. Calcd for C30H36CrK2O3; C: 68.92%; H: 6.94%, Found; C: 68.53%; H 7.43%. 2.4.5 Synthesis of [ t BuOCO]Cr III (THF) 3 (2) (Joseph M. Falkowski) In a nitrogen filled glove box (368mg, 1.04 mmol) of C rCl 2 Me(THF) 3 was dissolved in 20 mL of THF. In a separate vial 542 mg (1.04 mmol) of 1 was dissolved in 20 mL of THF. The solution of 1 was then added dropwise to the CrCl 2 Me(THF) 3 solution with stirring at room temperature and stirred for 5 h. All volatil es

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72 were removed in vacuo. Toluene was added and the solution was filtered. The filtrate was evaporated to dryness to provide an oil that was dissolved in a minimal amount of THF and cooled to 35 C to yield 292 mg of 2 as a green crystalline solid (44% yi eld). 1 H NMR (300 MHz, benzene d 6 7.48 ppm (br s), eff B 11 Selected IR data of 3 (neat film): (cm 1) 1390 (s), 1250 (s), 1260 (w), 1125 (w), 1063 (m), 1010 (m), 850 (s), 840 (w), 812 (w). Anal. Calcd f or C 38 H 48 CrO 5 ; C: 71.67%; H: 7.60%, Found; C: 71.24%; H 8.16%. 2.4.6 Synthesis of [ t BuOCO]Cr V In a nitrogen filled glove box, 89 mg (0.140 mmol) of 2 was dissolved in 15 mL of toluene. The reaction vessel was fitted with a y adapter and attached to a Schlenck line. The solution was degassed and then O 2 gas was admitted (1 atm). The solution quickly turned purple then over the course of 2 h turned red brown. The solution was degassed and the volatiles removed in vacuo yielding 58 mg of 3 as brown powder. The solid can be recrystallized by dissolving the brown powder in a minimal amount of toluene and cooling the solution to 35C (41% yield). Note: epr spectra of various samples of 3 routinely indicate the presence (2%) of a Cr V Cr V dinuclear comple x. 1 H NMR (300 MHz, benzene d 6 eff B 11 Selected IR data of 3 (neat film): (cm 1 ) 1577 (w), 1549 (w), 1471 (w), 1410 (s), 1359 (w), 1320 (w), 1242 (m), 1193 (m), 1110 (w), 1054 (w), 988 (s), 875 (m), 858 (w), 838 (w). Anal. Calcd for C 30 H 35 CrO 4 ; C: 70.43%; H: 6.90%, Found; C: 70.61%; H 6.78%.

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73 2 .4. 7 Synthesis of {[ t BuOCO]Cr IV (THF)} 2 ( O) (4) Complex 2 (0.210 g, 3.28 x10 4 mol) was dissolved in 5 mL of tolu ene. One half of the solution (2.5 mL) was placed in a separate Schlenk flask and stirred under an atmosphere of anhydrous O 2 for 1 h to form 3 as a red solution. The solution of 3 was evaporated to provide a red powder, which was brought into a glove box. The toluene solutions of 2 and 3 were combined yielding a deep purple color and then the solvent was evaporated to yield a purple powder. 1 H NMR (300 MHz, C 6 D 6 1/2 = 570 Hz) 16.89 1/2 = 675 Hz) 13.38, 1.79, and 30.57 1/2 = 540 Hz) ppm. The powder was dissolved in minimal Et 2 O and cooled to 35 C yielding purple crystals of 4 and a few green crystals of 2 ( Joseph M. Falkowski) 2.4. 8 Synthes is of [ t BuOCO]Cr III (OPPh 3 ) 2 ( 5 ) Solid triphenylphosphine oxide (0.158 g, 0.603 mmol) was added to a solution of 2 (0.193 g, 0.302 mmol) in toluene (20 mL) and stirred for 0.5 h. The solvent was removed by vacuum and the solid was dissolved in a minimal amo unt of CH 2 Cl 2 (5 mL) then layered with hexane to yield 237 mg of dark green crystalline 5 (73% yield). 31 P{1H} NMR (121.5 MHz, C6D6): not observed; 1H NMR ( 300 MHz,C6D6): = 7.62 (br), 6.67 (br), 4.28 (s, CH2Cl2), 1.46 (s), 1.24 (s), 0.88 (s), 3.35 (br), 6.91 (br), and 13.20 (br) ppm. eff = 4.62 B .11 Selected IR bands: 1437, 1406, 1277, 1266, 1185, 1169, 1121,1111, 721, and 719 cm 1 Anal. Calcd. for C 62 H 57 O 4 CrP 2 CH 2 Cl 2 ; C: 71.05; H: 5.58. Found; C: 71.00; H, 5.63. 2.4. 9 General Procedure for the Catalytic Oxidation of PPh 3 with O 2 by 2 Triphenylphosphine (0.962 g, 3.67 mmol) and 2 (8 mg, 0.012 mmol) was dissolved in hexanes (40 mL). 1 atm of O 2 (g) was admitted and the solution was stirred for 3 hrs.

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74 Triphenylphosphineoxide precipitated from solution and was filtered. The identity of the product and purity was verified by comparison of its 31 P{ 1 H} and 1 H NMR spectra to an authentic sample (yield = 66%, 0.676 g, 2.25 mmol). 2.4. 10 General Procedure for the Catalytic Oxidation of PPh 3 with air by 2 Triphenylphosphine (14 mg, 0.053 mmol) and 2 (5 mg, 0.007 mmol) was dissolved in C 6 D 6 (0.6 mL) and transferred to a NMR tube. The solution was exposed to flowing air and shak en. The light green solution turned dark upon shaking and gradually turned green, characteristic of [ t BuOCO]Cr III (OPPh 3 ) 2 ( 5 ). The reaction progress was monitored by 31 P{ 1 H} NMR until completion. 2.4. 11 Stoichiometric 18 O 2 Catalytic PPh 3 Oxidation Reaction Triphenylphosphine (9.3 mg, 0.036 mmol) and 2 (3 mg, 0.005 mmol) was dissolved in C 6 D 6 (0.6 mL) and transferred to a J Young NMR tube. The volume of the headspace in the J Young tube was determined to have a volume of 2.85 mL. The J Young tube was then at tached to a Schlenk line, the solution was frozen, and the headspace evacuated. Half equivalent of 18 O 2 (0.01777 mmol, 146 Torr, 2.25 mL) was admitted to the headspace and the tube sealed. The solution was thawed and the reaction was monitored by 31 P{ 1 H} N MR. When complete all volatiles were removed in vacua and an ESI MS of the resulting powder showed >96% of labelled 18 O=Ph 3 2 .4. 12 General S ample Preparation for Kinetic Measurements Oxygenated solvents were prepared by bubbling O 2 through the solvent for 30 minutes and stored under an atmosphere of O 2 for 6 hrs before use. The concentration of O 2 was taken to be the accepted literature value. 193 The reference absorbance was used as the initial concentration absorbance prior to reagent injection. A trend line was

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75 fitted to the first 80% of the reaction progress and then used to extrapolate the observed rate. Spectra wer e acquired in quartz cuvettes with septum caps. 2 .4. 13 Kinetic Simulations Kinetic simulations were fitted using Kinetica version 1.0.17. The simulated rate constants were obtained by fitting the experimental trials using a conjugate gradient optimizati on with default convergence criterion of 0.01 and a dampening factor for simplex of 0.9. 2 .4. 14 [2] vs time: O xidation of 2 with O 2 in THF A 50 mL stock solution of 2 (21.2 mg, 3.31 x10 5 mol) in THF was prepared. [ 2 ] variation: I n the sample cells, 0.25, 0.5, and 0.75 mL of stock solution of 2 was diluted with 2.25, 2.0, and 1.75 mL of THF, respectively. Oxygenated THF (0.5 mL) was added to the sample cell via syringe, and the absorbance was monitored at 341 nm for 400 s. [O 2 ] variation: S imilarly, 0.5 mL of stock solution of 2 was diluted with 1.5, 1.0, and 0.5 mL of THF and 1.0, 1.5, and 2.0 mL of oxygenated THF was added, respectively. [THF] variation: 0.5 mL of stock solution of 2 was diluted with 1.5, 1.0, and 0.5 mL of THF and 0.5, 1.0, and 1.5 mL of hexanes, respectively, and then 0.5 mL of oxygenated THF was added. [OPPh 3 ] variation: A 20 mL stock solution of OPPh 3 (73.3 mg, 2.63 x10 4 mol) in THF was prepared. A 0.5 mL of stock solution of 2 was diluted with 0.5, 1.0, and 1.5 mL of THF a nd 1.5,

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76 1.0, and 0.5 mL of OPPh 3 solution, and then 0.5 mL of oxygenated THF was added to the samples. [ 3 ] variation: A 10 mL of stock solution of 2 was exposed to an atmosphere of O 2 for a 0.5 h. The solution was dried under vacuum and redissolved in 10 mL of THF under an inert atmosphere. Samples containing 0.5 mL of stock solution of 2 were prepared using 0.25 and 0.5 mL of a stock solution of 3 with 1.75 and 1.5 mL of THF, respectively and then 0.5 mL of oxygenated THF was inserted into the samples. 2 .4. 15 Variable Temperature: O xidation of 2 with O 2 in THF A 25 mL stock solution of 2 (22.3 mg, 3.48 x10 5 mol) in THF was prepared. In the sample cell, 0.4 mL of the stock solution of 2 was diluted with 2.1 mL oxygen free THF. Oxygenated THF (0.5 mL) w as then added to the reaction cell via syringe and the absorbance was monitored at 341 nm for 300 s. The temperatures for the sample cells were set to 42 C, 25 C, 9 C, and 2 C and then 0.5 mL of ambient temperature oxygenated THF was added resulting in a temperature change of 1 2 C. As a result, the temperatures were taken to be 40, 20, 10, and 0 C. Between kinetic trials the temperature was re equilibrated to the initial thermal value. Special considerations were taken for 0 C trials in which a nitrogen filled atmosphere was used to prevent ice formation on the cuvette. Also for 10 C trials, the cuvette was periodically wiped to avoid water condensation.

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77 Figure 2 1 General me chanism for substrate oxidation including catalyst deactivation pathways of product inhibition and reversible formation of a M O M intermediate. Figure 2 2 Additional coordination site provi ded by a trianionic pincer ligand over tetradentate ligands. Figure 2 3 Synthesis of 1

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78 Figure 2 4 Synthesis of 2 Figure 2 5 Molecular structure of 2 with ellipsoids at 50% probability. Hydrogen atoms and two THF molecules removed for clarity. The two mutually trans coordinated THF molecules are distorted over two positions and are removed for clarity. Selected bond lengths ( ):

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79 Figure 2 6 Activation of O 2 by 2 to yield complex 3 Figure 2 7 Molecular structure of 3 with ellipsoids at 50% probability. Hydrogen atoms removed for clarity. Selected bond lengths ( ) and angles (): 165.27(8).

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80 Figure 2 8 Plot of the SOMO ( A LUMO ( B ) of model complex contour level 0.03 a.u.. Figure 2 9 Aerobic oxidation of PPh 3 catalyzed by complex 2

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81 Figure 2 10 UV vis spectral change of 2 in THF upon addition of O 2 (25 C). Figure 2 11 Concentration vs time (s) for the oxidation of 2 by O 2 in THF; within 1 st 80% (blue), after 80% (red) (25 C). 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 300 350 400 450 500 Absorbance wavelength (nm) 0 2 4 6 8 10 12 0 50 100 150 200 [2] x10 5 (M) time (s) [2] = 1.10E-4 M

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82 Figure 2 12 Concentration ( 2 ) vs ti me (s) for the oxidation of 2 (0.55 1.65 ( x10 4 ) M) with O 2 (1.66 x10 3 M) in THF (25 C). Figure 2 13 Plot of 2 vs [ 2 ] ([ 2 ] = 0.55 1.65 x10 4 M; [O 2 ] = 1.66 x10 3 M (THF, 25 C). 0 2 4 6 8 10 12 14 16 18 0 50 100 150 200 [2] x10 5 (M) time (s) [2] = 1.10E-4 M [2] = 0.55E-5 M [2] = 1.65E-4 M 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0.5 1 1.5 2 [2]/ t x10 6 (M/s) [1] x10 4 M

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83 Figure 2 14 Concentration ( 2 ) vs time (s) for the oxidation of 2 (1.10 x10 4 M ) with O 2 ( 1.66 6.66 (x10 3 ) M ) in THF (25 C). Figure 2 15 Plot of rate 2 vs [O 2 ] ([ 2 ] = 1.10 x10 4 M; [O 2 ] = 1.66 6.66 (x10 4 ) M) in THF (25 C). 0 2 4 6 8 10 12 0 50 100 150 200 [2] x10 5 (M) time (s) [O2] = 1.66E-3 M [O2] = 3.22E-3 M [O2] = 4.99E-3 M [O2] = 6.66E-3 M 0 0.5 1 1.5 2 2.5 3 3.5 4 0 2 4 6 8 [2]/ t x10 6 (M/s) [O 2 ] x10 3 (M)

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84 Figure 2 16 Plot of rate 1 vs X THF ([ 2 ] = 1.10 x10 4 M; [O 2 ] =1.66 x10 3 M; THF/hexa ne (mL:mL) = 2.5:0.5, 2.0:1.0, 1.5:1.5) at 25 C. Figure 2 17 Concentration of 2 (1.84 x10 4 M) vs time in THF upon addition of O 2 (1.66 x10 3 M) at 40 C (red), 20 C (yellow), 10 C (light blue), and 0 C (dark blue). 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0.5 0.6 0.7 0.8 0.9 1 [2]/ t x10 6 (M/s) X THF 0 2 4 6 8 10 12 14 16 18 20 0 100 200 300 400 500 600 700 [2] x10 5 (M) time (s) 25 C 10 C 0 C

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85 Figure 2 18 Concentration of 2 vs time (s) for the oxidation of 2 (1.10 x10 4 M) by O 2 ( 1.66 x10 3 M ) with increasing [ 3 ] (0, 5.5 x10 5 and 1.10 x10 5 M) in THF (25 C). Figure 2 19 Plot of 2 2 (1.10 x10 4 M) by O 2 ( 1.66 x10 3 M ) with increasing [ 3 ] (0, 0.55 x10 4 and 1.10 x10 4 M) in THF (25 C). 0 2 4 6 8 10 12 0 50 100 150 200 [2] x10 5 (M) time (s) [3] = 0 M [3] = 0.55E-4 M [3] = 1.1E-4 M 0 0.5 1 1.5 2 2.5 3 0 5 10 15 [2]/ t x10 6 (M/s) [3] x10 5 (M)

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86 Figure 2 20 Equilibrium between 2 and 3 and the dime r adduct 5 Figure 2 21 Molecular structure of {[ t BuOCO]Cr IV (THF)} 2 O ( 5 ) with ellipsoids drawn at the 50% probability level and hydrogen atoms and an ether lattice molecule removed for clarity.

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87 Figure 2 22 The bonding MO and ligand field splitting diagram of the Cr IV ion in 5 Figure 2 23 Variable temperature high frequency (240 GHz) powder EPR spectra of major 5 and minor 2 The boxed part of the spectrum at 300 K is due to t he noise from the spectrometer electronics.

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88 Figure 2 24 Simulated (a) and experimental (b) powder EPR spectra of 5 and 2 at 240 GHz and 4.5 K. The simulated spectrum (b) is the sum of the individually simulated spectra of 5 and 2 Peak assignments: Complex 1 (S = 1.5): allowed transitions = 3, 5, 6, 7 and 9, forbidden transition = 1; Complex 5 (S = 2): allowed transitions = 4, 5, 6, 7 and 8, forbidden transition = 2. The resonances 5, 6 and 7 are overlapping signals from bo th 2 and 5

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89 Figure 2 25 Molecular structure of {[ t BuOCO]Cr IV (THF)} 2 O ( 5 ) with ellipsoids drawn at the 50% probability level and hydrogen atoms and an ether lattice molecule removed for clarity.

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90 Figure 2 26 Proposed mechanism for O 2 activation by 2

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91 Figure 2 27 Simulated [ 2 ] (0.55 1.65 x10 4 M) vs time (s) at [O 2 ] = 1.66 x10 3 M. Correlation (R 2 ) values of simulated and e xperimental trials at 0.55 x10 4 M 2 (0.999), 1.10 x10 4 M 2 (0.999), and 1.65 x10 4 M 2 (0.999) (THF, 25 C). Figure 2 28 Simulated [ 2 ] (1.10 x10 4 M) vs time (s) at different concentrations of [O 2 ] (1.66 6.66 x10 3 M). Correlation (R 2 ) values of simulated and averaged experimental trials at 1.66 x10 3 M O 2 (0.999), 3.33 x10 3 M O 2 (0.998), 4.99 x10 3 M O 2 (0.999) and 6.66 x10 3 M O 2 (0.995) (THF, 25 C). 0 2 4 6 8 10 12 14 16 18 0 50 100 150 200 [2] x10 5 (M) time (s) exp. [2] = 1.65E-4 M exp. [2] = 1.10E-4 M exp. [2] = 0.55E-4 M sim. [2] = 1.65E-4 M sim. [2] = 1.10E-4 M sim. [2] = 0.55E-4 M 0 2 4 6 8 10 12 0 50 100 150 200 [2] x10 5 (M) time (s) exp. [O2] = 1.66E-3 M exp. [O2] = 3.22E-3 M exp. [O2] = 4.99E-3 M exp. [O2] = 6.66E-3 M sim. [O2] = 1.66E-3 M sim. [O2] = 3.22E-3 M sim. [O2] = 4.99E-3 M sim. [O2] = 6.66E-3 M

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92 Table 2 1 Average calculated rate c onstants for the oxidation of 2 (1.84 x10 4 M) with O 2 (1.66 x10 3 M) in THF at 25 C, 20 C, and 0 C. T (C) 25 10 0 k 1 (s 1 ) 2.6( 0.6) 1.2( 0. 1) 0.5( 0. 3) k 4 (M 1 s 1 ) 396.8( 0. 7 ) 179( 8) 50( 9) k 4 /k 5 6.1( 2.3 ) x10 3 2.9( 0.4 ) x10 3 1.8( 0.6 ) x10 3 Figure 2 29 Simulated [ 2 ] vs time for the oxidation of 2 (1.65 x10 4 M and 1.84 x10 4 M) with O 2 (1.66 x10 3 M) using the average calculated rate constants from Table 1. 0 2 4 6 8 10 12 14 16 18 20 0 100 200 300 400 500 600 700 [2] x10 5 time (s) 25 C 10 C 0 C 25 C simulation 10 C Simulation 0 C Simulation

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93 Figure 2 30 A plot of [ 2 ] vs time with increasing [OPPh 3 ] (0 0.1 M). [O 2 ] = 1.66 x10 3 M and [ 2 ] = 1.10 x10 4 M (THF, 25 C). Figure 2 31 Synthesis of 4 0 2 4 6 8 10 12 0 50 100 150 200 [2] x10 5 (M) time (s) [OPPh3] = 0 M [OPPh3] = 2.33E-3 M [OPPh3] = 4.66E-3 M [OPPh3] = 6.99E-3 M [OPPh3] = 1.04E-1 M

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94 Figure 2 32 Molecular structure of 4 with ellipsoids at 50% probability. Hydrogen atoms and CH 2 Cl 2 removed for clarity. Selected bond lengths ( ) and angles (): 103.62(6).

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95 Figure 2 33 New general mechanism for substrate oxidation featuring

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96 CHAPTER 3 THE INFLUENCE OF REV ERSIBLE TRIANIONIC P INCER OCO 3 OXO Cr IV DIMER FORMATION ([Cr IV ] 2 ( O)) AND DONOR LIGANDS IN OXYGEN ATOM TRANSFER (OAT) 3 .1 Introduction Tr ianionic pincer ligand s present multiple approaches to creating reactive complexes for catalysis and/or small molecule activation. In addition, a trianionic pincer ligand can be used as a model platform to investigate atom transfer processes that may be re levant to other catalytic systems. For example, Veige and coworkers investigated the N atom transfer from an anionic molybdenum nitride to synthesize nitriles from acid chlorides. 38 These model syste ms are of consi derable importance in the quest for catalysts that incorporate dinitrogen into organic substrate. 230 238 In Chapter 2 we presented the distinct advantages of using a trianionic OCO pincer ligand for oxidation cata lysts. Here we will demonstrate potential problems that can occur du ring oxidation catalysis due to the formation of oxo dimers in solution ( Figure 3 1) In particular, investigating the role of o xo dimer formation during oxygen atom transfer ( OAT ) to PPh 3 provides an informative comparison to tetradentate ligands. During a catalytic cycle, OAT from a metal center to substrate is deceptively simple for a straightforward reaction involving the transfer of a single atom. The mechani sm of this process is dependent on the metal center, the oxidation state, and the corresponding d electron count of the complex 139 Ev en for a simpl e OAT from a high valent d 0 metal oxo complex t heoretical and experimental studies indicate the rate M. E. O'Reilly, T. J. Del Castillo, K. A. Abboud and A. S. Veige, Dalton Trans 2012, 41 2237 2246. Re produced by permission of The Royal Chemical Society.

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97 of OAT is dependent on a combination of steric and electronic properties of the substrate and metal coordination sphere which dictates the symmetry, and t herefore the density of states, 118, 119, 239 that can mix at the transition state. 118 121, 136, 240 Another dimension of comp lexity is the role of donor ligands during the OAT event D onor ligands are w ell known to accelerate substrate oxidation by chromium and manganese catalysts. 241 One hypothesis for the rate enhancement is that the donor ligand coordinat es trans to the M and th ereby weaken s the M d 128, 189, 242 247 Another possible explanation is a change in the ancillary ligand orientation, allowing for a more accessible pathway for the subtrate to approach the M orbital. Evidence for the latter appears in the enantioselective epoxidation of olefins 241, 248 250 where c oordinating a donor ligand to a chiral salen complex alters the ligand framework influencing asymmetric induction around the M 246, 251 256 Similarly, adding a chiral donor ligand to an ac hiral metal salen catalyst can also induce asymmetric OAT to olefins. 253 256 Weakening of the M and ancillary ligand rearrangement by donor ligands provide reaso nable explanations for the observed rate enhancement, yet donor ligands may have an other more subtle effect. Recent studies of OAT from chromium 141, 155 158, 160, 244, 257 and manganese 161 165, 168 175, 258 260 oxidation catalysts postulate that the formation of an oxo complexes from t he comproportionation of M n+ and M (n+2)+ =O species are prevalent during catalysis Despite their prevalence, oxo complexes are elusive and ill characterized One notable exception is an isolable [CpCr IV Me 2 ] 2 ( O) but the complex wa s characte r ized only by 1 H NMR spectrscopy 187 The oxo intermediate s 261 are thermodynamic sinks that suppres s t he rate of oxidation ( Figure 3

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98 1). 140, 141, 260 262 S donor ligands promote the dissociation of [(L)Mn IV ] 2 ( O) and [(L)Cr IV ] 2 ( O) (L = salen or porphyrin) intermediates. 140, 158, 169, 215 Thus an overlooked explanation is that donor ligands enhance substrat e oxidation by prevent ing oxo dimer formation. Though the formation of oxo intermediates during oxidative catalysis has been detected using 1 H NMR, 164, 165 EPR, 158 UV visisble spectrophotometry (UV vis), 175 and mass spectrometry; 157, 163, 168, 246, 257 259 a convenient means to identif y their presence is by evaluting the kinetic profile of the OAT reaction Bruice et al. provide the only example of the kinetic consequence of oxo intermediates during OAT from a (L)Cr V O complex (L = porphyrin). 156 The depletion of monomeric (L)Cr V O follows a non standard kinetic decay profile, and a str ong absorption corresponding to a oxo intermediate increases initially then slowly declines over the reaction period. The synthesis of complexes 3 and 4 from Chapter 2 ex e mplify the rare occurance of an isolable Cr V IV ) 2 ( O) species that presents the opportunity to directly rep ort on the influence of a oxo dimer during OAT. We now present the first mechanistic investigation of OAT from an discrete oxo dimer. In addition, we are able to examine the role of donor ligands on the rate of OAT in relation to oxo dimer participat ion. 3 .2 Results and Discussion 3 .2.1 Identity of the A ctive OAT A gent in THF The infrared spectrum of complex 3 exhibits a strong Cr V 1 Solution EPR measurements confirm a d 1 Cr V oxidation state for 3 However, routinely prepared po wder samples of 3 prior to recrystallization, exhibit an EPR spectrum with two separate d 1 signals at g iso = 1.9747 and g iso = 1.9762. Recrystallized 3 produces a

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99 single resonance at 1.9747 in toluene ( Figure 3 2, spectrum A ). Dissolving the same materia l used to generate spectrum A in 50% v/v THF/CH 2 Cl 2 yields the second signal at 1.9762 ( Figure 3 2 spectrum B). The interconversion of two distinct EPR signals of complex 3 by changing the solvent from toluene to THF/CH 2 Cl 2 suggests the two different spec ies are [ t BuOCO]Cr V (O)(THF) ( 3 ) and [ t BuOCO]Cr V (O)(THF) 2 ( 3a ) ( Figure 3 3) In the latter, a second THF binds to yield the coordinately saturated species 3a Figure 3 4 depicts the changes in the EPR spectrum of [ t BuOCO]Cr V (O)(THF) ( 3 ) (red) in toluene up on addition of one half (green) and a full equivalent of THF (blue), indicating an equilibrium between 3 and 3a ( Figure 3 3 ). 3 .2.2 Mechanism of OAT from M ononuclear 3 and 3a Both 3 and 3 a transfer an oxygen atom to trialkylphosphines to yield [ t BuOCO]Cr II I (THF) 3 ( 2 ) and trialkylphosphine oxides. Figure 3 5 illustrates the OAT from 3 a in THF solution to yield 2 UV vis spectrophotometry provides a suitable method for studying the OAT. A color change from red brown to green occurs when 3 a reacts with PPh 3 to form 2 and OPPh 3 36 Figure 3 6 depicts the time dependent changes in absorption spectra from a 0.11 mM solution of 3 a upon addition of a ten fold excess of PP h 3 Measuring the changes in the absorption at 405 nm provides suitable data to plot the relationship between the concentration of 3 a vs time. Figure 3 6 depicts a first order curve for the depletion of 3 a under pseudo first order conditions. A ln[ 3 a ] vs t ime plot confirms the first order dependency in 3 a ( Figure 3 7 ) and the slope provides an experimental value for k obs

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100 3 .2.3 [PPh 3 ] Dependence A series of experiments varying the concentration of PPh 3 from 1.07 to 2.14 mM reveals a first order dependence in [PPh 3 ]. Figure 3 8 depicts a plot of k obs vs [PPh 3 ] from the pseudo first order rate law, d[ 3a ]/dt = k obs [ 3a ] where k obs = k 1 [PPh 3 ]. Dividing the measured k obs by [PPh 3 ] yields the rate constant k 1 3 .2.4 Variable Temperature Studies and Eyring Plot Conducting the OAT between 0 and 40 C (1 C) provides the temperature depend e See Appendix for the accompanying raw data. Figure 3 9 depicts a ln(k 1 /T) vs 1/T plot. The for OAT is 18(3) cal/molK and is consistent with a nucleophilic attack by phosphine during the rate determining step. The relatively low enthalpy of activation is 9.4(0.8) kcal/mol) corresponds to a fast reaction that is complete within two minutes (15 C). 3 .2.5 PR 3 Size Rate Dependence Performing spin unrestricted density functional the ory calculations on 3 an analogue of 3 having methyl groups in place of tert butyl, elucidates the possible Cr V orbital involved in nucleophilic attack by PPh 3 The LUMO is primarily a Cr V O combination, with 62% Cr, 26% oxo, 2.6% trianionic pince r ligand, and 9.4% THF character. The Cr V orbital is a reasonable point of attack by external nucleophiles such as PPh 3 Nucleophilic attack of the Cr V orbital should be more favorable for less sterically bulky phosphines. In keeping with this h ypothesis, th e relative rates of OAT for trimethylphosphine (PMe 3 ), triphenylphosphine (PPh 3 ), and tri tert butylphosphine (P t Bu 3 ) are slower for larger phosphines. Table 3 1 contains the rates of OAT for the

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101 three different phosphines at 15 C and equimo lar concentrations. The relative rates of k obs for PMe 3 :PPh 3 :P t Bu 3 are 2976:235:1, respectively. These results are consistent with a bimolecular side on attack of the Cr V 118, 119, 263 Figure 3 10 depicts a straightforward mechanism that fits the kinetic data. The incoming PPh 3 attacks the electrophilic oxygen atom of 3 a cleaving the Cr V nd. The first order dependence on both 3 a and PPh 3 ( 18(3) cal/mol) support k 1 as the rate determ ining step. In subsequent fast steps, THF displaces the coordinated OPPh 3 3 .2.6 Role of Donor Ligands on OAT Literature precedent suggests that strongly coordinating solvents and ligands, such as phosphine oxides, methanol, and acetonitrile, accelerate t he rate of OAT. 128, 189, 242 247 Monitoring the rates of OAT at different concentrations of OPPh 3 (0 1.31 mM) in THF allows the determination of OPPh 3 i nfluence in OAT. Figure 3 11 depicts a plot of k obs vs [OPPh 3 ] ( d[ 3a ] = k obs [ 3a ]) and indicates OPPh 3 does not affect the overall OAT rate. Using this data k 1 at 22 C is 69.5(1.9) M 1 s 1 Similarly, solvent coordination may in fluence the rate of OAT. T able 3 2 contains the observed rates for OAT in acetonitrile (MeCN), CH 2 Cl 2 and THF Surprisingly, more strongly coordinating solvents, such as acetonitrile, do not change the rate. EPR confirms indeed the MeCN coordinates to 3 but rather weakly since ap plying vacuum readily removes MeCN and the IR spectrum does not contain any C N stretching. The OAT reactions in CH 2 Cl 2 did not yield isosbestic points without the addition of THF. The THF is necessary to satisfy the coordination sphere of the resulting re duced Cr III ion. Adding 50 L of THF to the CH 2 Cl 2 trials results in clean isosbestic points but the rate is identical to OAT in THF.

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102 3 .2.7 Synthesis and Characterization of [ t BuOCO]Cr V (O)(CH 2 PPh 3 ) (6) One of the strongest neutral two donor ligands is the phosphorus ylide R 3 P + CH 2 264 even stronger than N heterocyclic carbene (NHC) ligands. 265 To investigate the potential role this donor ligand has on OAT, complex 3 was treated with o ne equivalent of Ph 3 PCH 2 in toluene to yield [ t BuOCO]Cr V (O)(CH 2 PPh 3 ) ( 6 ) according to Figure 3 12 The infrared spectrum of 6 reveals a strong absorption at 976 cm 1 corresponding to a weaker Cr V 3 which appears at 988 cm 1 in 3 The i ncreased electron density donated to the Cr V ion by the phosphorus ylide 2 P + Ph 3 versus THF better stabilizes the +5 oxidation state of chromium. donation from the oxo relaxes and weaker O bond forms. Consistent with a more electro n rich Cr V ion, the cyclic voltammagram of 6 in CH 2 Cl 2 ( Figure 3 13 ) reveals a first reduction potential at 1.968 V, whereas the first reduction potential for the Cr V ion in 3 appears at 0.062 V. Essentially, complex 6 is more difficult to reduce than 3 and a consequence of the large negative reduction potential is that complex 6 is not thermodynamically competent to oxidize PPh 3 or PMe 3 Figure 3 14 depicts the solution EPR spectrum of 6 in hexanes. The weak satellite signals correspond to the 53 Cr isot ope (S = 3/2) and yields a hyperfine splitting of 18.58 mT. The intense resonance at g value = 1.982 corresponds to the remaining Cr isotopes and is a triplet due to coupling to the protons of C H 2 PPh 3 with a hyperfine splitting of 0.199 mT. A second hyperf ine splitting (A( 31 P) = 0.066 mT) appears as weak shoulders lying to the right of the main signals. EPR simulations using E asyspin.3.1.6 266 indicate the second hyperfine splitting corresponds to a doublet arising from coupling to 31 P (S = ).

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103 Brown single crystals deposit at 35 C from a concentrated solution of 6 in toluene. Figure 3 15 depicts the molecular structure of 6 obtained by sin gl e crystal X ray analysis Complex 6 is pseudo C s symmetric and consists of a Cr V ion in a distorted square pyramidal coordination geometry with an Addison parameter of 0.053. 194 The Cr oxo bond length is 1.5699(11), which is statistically identical to the corresponding bond found in 3 (1.5683(18) ), 57 and is typical for Cr V oxo complexes. 67 75 The geometry of 6 distorts significantly from that of the precursor 3 The C12 Cr O4 angle of 145.05(7) is significantly smaller than in 3 (165.27(8)), reflecting the change from THF ligation to CH 2 PPh 3 Also, the central aryl ring of the pincer ligand is severely bent out of plane from the peripheral rings to create a but terfly orientation ( Figure 3 15 ). Planes comprised of the peripheral arene carbon atoms bisect the plane comprised of the central rin g carbons by 32.8 for 6 and 28.1 for 3 3 .2.8 Role of D inuclear oxo D imer {[ t BuOCO]Cr IV (THF)} 2 ( O) ( 4 ) in OAT Few of the previous studies that propose competent oxo Cr and Mn dimer species in oxidation catalysis were able to assess whether the dimers participate in OAT to substrate. 156, 158, 161 Offering a chance to examine this directly, complex 4 was tested as an OAT transfer agent. UV vis spectrophotometry is a suitable method for monitoring the OAT from the oxo dimer 4 to PPh 3 in no ncoordinating solvents. Figure 3 16 depicts the changes in absorption spectra of 4 in CH 2 Cl 2 upon addition of PPh 3 Observing the decay of 4 is optimal at a wavelength of 850 nm; the interference from Cr V O (red) and Cr III (green) absorption is minimal.

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104 Measuring the changes in absorption at 850 nm produces a plot of [ 4 ] vs time. Figure 3 17 depicts the average concentration vs time profile of three experimental trials. The decay of [ 4 ] vs time does not follow first order kinetics as exemplified in the non linear ln[ 4 ] vs time plot ( Figure 3 17 ) Figure 3 18 depicts the time dependent decay of complex 4 in the presence of PPh 3 (1.10, 2.21, and 4.42 (x 10 3 ) M). The data clearly indicate a zero order dependence on the concentration of PPh 3 suggesting complex 4 must first break apart into mon onuclear Cr III and Cr V (O) prior to OAT. Figure 3 19 depicts the proposed mechanism of OAT from 4 to PPh 3 in CH 2 Cl 2 The rate determining step is the fragmentation of 4 to provide a proposed low coordinate Cr III species 7 and 3 The dissociation of 4 is re latively slow, and the equilibrium favors the dimer. Upon cleavage of 4 the newly formed 3 reacts with PPh 3 to yield OPPh 3 and a second equivalent of 7 The exact composition of the low coordinate complex 7 is unknown. As the concentration of OPPh 3 builds a more accurate description of the Cr III containing products would include different coordination complexes with bound OPPh 3 and THF. 57 Varying the concentration of 4 reveals that OAT occurs faster at more dilute concentrations. This is counterintuitive. Why would a higher concentration of 4 inhibit OAT if complex 4 is the source of the OAT agent 3 ? Figure 3 20 depicts the average (three independent measurements) decay of 4 at three different concen trations. The [ 4 ] vs time plots were simulated using Kinetica 2003 using the decay plots of 4 as the input data, and the reaction scheme in Figure 3 19 as the model mechanism. The kinetic trials established above ( Figure 3 11 ) for the direct OAT from 3 a t o PPh 3 in THF provide

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105 an experimentally determined value for k 2 (formerly k 1 in Figure 3 5 ) as 69.5(1.9) M 1 s 1 (22 C). An approximate rate constant for k 1 is determined by analyzing the rate law for the mechanism. Equation 3 1 depicts the mathematical expression of the rate law for the mechanism in Figure 3 19 (3 1) (3 2) At early reaction times ( t < 150 s), the concentration of 7 is negligle such that k 2 [PPh 3 ] >> k 1 [ 7 ], thus simplifying Equation 3 1 to Equatio n 3 2 and plotting ln[ 4 ] versus time during this period provides a linear correlation and k 1 as the slope ( Appendix ). For the conditions [ 4 ] = 3.11 x10 4 M, [PPh 3 ] = 1.1 x10 3 M, 22 C, in CH 2 Cl 2 ; k 1 = 8.38(0.69) x10 4 s 1 (averaged from three independen t measurements). The rate law also (Equation 3 1) provides an opportunity to experimentally determine a value for k 1 Equation 3 3 depicts the f ull integrated rate law from Equation 3 1. The [Cr] tot is the total concentration of chromium as defined in Equation 3 4 (3 3) where, (3 4) Employing the assumption that k 1 [Cr] tot >> k 2 [PPh 3 ] simplifies Equation 3 3 to Equation 3 5. Co incidentally, the sa me rate law is obtained from Equation 3 1 directly, assuming k 1 [ 7 ] >> k 2 [PPh 3 ], an assumption which is only valid at the end of the reaction time (t > 5000 s) when [ 7 ] accumulates. (3 5)

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106 Employing the identical conditions for the determination of k 1 ( [ 4 ] = 3.11 x10 4 M, [PPh 3 ] = 1.1 x10 3 M, 22 C, in CH 2 Cl 2 ) Figure 3 21 depicts the linear correlation plot of 2[ 4 ] [Cr] tot ln[ 4 ] vs time. The slope is the product of the rate constants k 1 k 2 [PPh 3 ], and 1/k 1 Since the values of [PPh 3 ], k 1 ( 8.38(0.69) x10 4 s 1 ) and k 2 (69.5(1.9) M 1 s 1 are known, the approximate value of k 1 = 1.95(0.23) x10 3 M 1 s 1 Using the k 1 and k 1 rate constants, K eq = k 1 /k 1 for the formation of 4 from Cr III and Cr V (O) in CH 2 Cl 2 is 2.33(0.36) x10 6 Kinetic simulations of the concentration versus time profiles were conducted to examine the validity of the mechanism proposed in Figure 3 19 Simulating the concentration versus time profiles for t he reaction of 4 with PPh 3 and the elementary reaction steps in Figure 3 19 provides an estimate of the rate constants k 1 and k 2 /k 1 Since the value of k 2 (previously labeled k 1 above) is experimentally determined from OAT from 3a to PPh 3 in THF, the k 2 rate constant was fixed at 69.5 M 1 s 1 Table 3 3 provides the average simulated rate constants, which are close in magnitude to the experimental values. The corresponding calculated equilibrium constant for the formation of 4 is K eq (calc) = 1.66(0.31) x 10 6 For visual verification, the calculated rate constants from Table 3 3 can be employed to regenerate the decay of [ 4 ] versus time profiles. Figure 3 22 depicts the concentration versus time profiles for [ 4 ] = 3.11, 1.56, and 0.78 (x10 4 ) M and fro m visual inspection the calculated rate constants provide a good fit to the experimental data. Statistically, the correlation values between experimental decay and simulated decay profiles are 0.999, 0.999, and 0.990 for [ 4 ] = 3.11, 1.56, and 0.78 (x10 4 ) M, respectively Small deviations between simulated and experimental data occur toward

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107 the end of the reaction; more specifically the simulated decay lags behind the experimental decay. This deviation arises from the formation of OPPh 3 as the reaction prog resses, which is known to bind strongly to Cr III and thus shifts the equilibrium in favor of mononuclear Cr III and Cr V O complexes over the dimer 4 57 Finally, adding two equivalents of OPPh 3 to a C 6 D 6 solution of 4 results in disappearance of the dimer signals at 18.58, 16.32, and 27.22 ppm in the 1 H NMR, confirming OPPh 3 role in the equilibrium. Finally, in THF, as soon as the Cr V (O) complete s an OAT event, the Cr(III) complex that forms coordinates a THF molecule which prevents dimerization, thus the reactions are generally swift (150 s to complete). However, in non donor solvents the Cr(III) that forms rapidly combines with Cr V (O) to form th e dimer 4 exemplified by the large equilibrium constant K eq = 2.33(0.36) x10 6 Indeed, this is observed; upon additional of PPh 3 to 3 in CH 2 Cl 2 the immediate (<10 s) formation of the oxo dimer 4 is observed as a broad absorption from 700 nm to 850 n m ( Figure 3 23 ). Plotting the change in absorption at 800 nm versus time indicates the reaction requires more than 3000 s to complete. 3 .3 Conclusions Trianionic pincer ligand are a versatile ligand platform to investigat e oxygen atom transfer reactions I n Chapter 2, we presented an aerobic oxidation catalyst featuring a trianionic OCO pincer ligand that avoids catalyst deactivation prev enting reoxidation by product inhibition and oxo dimerization. The synthesis of complex es 3 and 4 examplify a rare occurance of an isolable isolation Cr V and (Cr IV ) 2 ( O) species, which lends itself to OAT investigation In particular, i nterest in the OAT from M O M stems from the hindrance that M O M dimer formation present s during catalyzed oxidation reactions

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108 (Figure 3 1). Previous kinetic analysis of OAT reactions measuring the indirect formation of Cr O Cr species postulate that the dimers do not transfer an oxygen atom directly to substrat e. Rather, the dimer breaks apart prior to OAT. By observing the OAT directly from complex 4 our study provides additional evidence that O atom transfer indeed occurs after dimer cleavage ( Figure 3 19 ). The OAT from 3 a to PPh 3 in THF occurs quite swiftly (~ 100 s to completion), yeilding an overall second order rate law. The rate of OAT is dependent on the size of the substrate. In THF, the relative rates (k obs ) of OAT from 3a to PMe 3 PPh 3 and P t Bu 3 are 2976:235:1 s 1 corresponding to greater difficult y experience d by sterically bulky substrate in achieving the proper orientation needed for OAT. T he OAT from complex 4 to PPh 3 is remarkably slow taking over 5 h to complete. The zero order dependence in PPh 3 indicates that the dimer dissociates prior to OAT. However, the OAT reaction from 4 does not follow first order kinetics. The OAT from 4 reveals a unique kinetic feature where higher concentration of 4 yie ld s a slower rate of OAT which is contrary to expected results since 4 is the source of Cr V (O). Kinetic analysis shows that the kinetic profile anomalies arise from a product inhibition mechanism where the formation of the Cr III species, 7 impedes the dissociation of the 4 EPR data indicates that in THF complex 3 coordinates a second THF ligan d to provide 3 a The availability of a sixth coordination site allows us to investigate donor ligand effect s on the rate of OAT. Surprisingly, t he OAT from 3 to PPh 3 conducted in THF, MeCN, and CH 2 Cl 2 /THF reveals no rate acceleration or retardation in any of the solvents. Adding OPPh 3 a donor ligand, likewise does not affect the rate of OAT.

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109 However, the OAT from 3 in non coordinating CH 2 Cl 2 takes over 4 h to complete and UV vis spectroscopy reveals the immediate formation of the O dimer 5 Using the trianionic pincer ligand as a platform to investigate OAT, we present a case for the role of donor ligands. This study allows us to conclude that the role of donor bond during OAT. In fact adding a very strongly donating ligand can prevent OAT by making the transfer thermodynamically unfavorable, as in the case of [ t BuOCO]Cr V O(CH 2 PPh 3 ) ( 6 ). Instead, the donor ligands serve an important role during OAT by preventing rate inhibiting oxo d imer formation. It is possible that prior OAT studies exhibiting rate enhancement from donor ligands have been misinterpreted, and instead the rate increases are actually the consequence of breaking up putative oxo dimers. Finally, this work illustrates the care that must be taken when selecting an appropriate donor ligand oxo dimer formation while still thermodynamically permitting OAT. 3 .4 Experimental Section 3 .4.1 General Considerations Unless specified otherwise, all manipulations wer e performed under an inert atmosphere using standard Schlenk or glovebox techniques. Pentane, hexanes, toluene, acetonitrile, dichloromethane, and tetrahydrofuran were dried using a GlassContour drying column. Benzene d 6 (Cambridge Isotopes) was dried ove r sodium benzophenone ketyl, distilled or vacuum transferred, and stored over 4 molecular sieves. All other reagents were purchased from commercial vendors and used without further purification.

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110 3 .4.2 Analytical Techniques Kinetic Simulations: Kinet ic simulations were performed using Kinetica 2003 software. NMR Techniques: NMR spectra were obtained on Varian Gemini 300 MHz, Varian Mercury Broad Band 300 MHz, or Varian Mercury 300 MHz spectrometers. 1 H a nd 13 C{ 1 H} NMR spectra, the solvent peak was referenced as an internal reference. Elemental Analysis: Combustion analyses were performed at Complete Analysis Laboratory Inc., Parsippany, New Jersey. IR Techniques: I nfrared spectra were obtained on a The rmo Scientific Nicolet 6700 FT IR. UV Vis Techniques: UV vis spectra were acquired on a Hewlett Packard 8453 spectrophotometer and variable temperatures were maintained using Fisher Scientific Isotemp 10065. Spectra were acquired in quartz cuvettes fitt ed with septum caps. Electrochemical Cyclic Voltammograms Techniques: (Marie C. Corriea) Electrochemical experiments were performed at ambient temperature in a glove box using an EG&G PAR model 263A potentiostat/galvanostat and a three compartment H cell separated by a medium porosity sintered glass frit. Electrolytic solutions consisted of 0.1 M tetrabutylammonium hexafluorophosphate (TBAH) dissolved in either CH 2 Cl 2 or THF. Cyclic voltammograms (CV) were recorded at 100 mVs 1 in 4 mL electrolytic solutio n with 5 mM of the complex. A glassy carbon electrode (3 mm diameter) was used as the working electrode and a platinum flag as the counter electrode. All potentials are reported versus SCE and referenced to Ag/Ag + The reference electrode consisted of a s ilver wire immersed in a freshly prepared acetonitrile solution of 0.01 M

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111 AgNO 3 and 0.1 M TBAH encased in a 75 mm glass tube with a fitted Vycor tip. The E o values for the Fc + /Fc couple in CH 2 Cl 2 and THF were +0.47 V and +0.58 V versus SCE respectively. 267 EPR Techniques: EPR measurements were conducted using a Bruker Elexsys 500 Spectrometer, at the X band, microwave frequency ~9.4 GHz in the temperature range of 4 to 300 K. The microwave frequency was measured with a built in digital counter and the magnetic field was calibrated using 2,2 diphenyl 1 picrylhydrazyl (DPPH; g = 2.0037). The temperature was controlled using an Oxford Instruments cryostat, to accurac y within 0.1 K. Modulation amplitude and microwave power were optimized for high signal to noise ratio and narrow peaks. The EPR spectra were acquired in a quartz capillary of approximately 1x3 mm IDxOD at room temperature using a commercial Bruker Elexs ys E580 spectrometer, equipped with a high Q cavity (ER 4123SHQE). General instrumental parameters are as follow: 100 kHz modulation frequency, 0.2 1 G modulation amplitude, 0.6 mW microwave power, 9.87 GHz microwave frequency, 20.48 ms time constant, and 81.92 ms conversion time/point. 3 .4.3 Synthesis of [ t BuOCO]Cr V O(CH 2 PPh 3 ) (6) A 10 mL THF solution of 3 (0.153 g, 0.300 mmol) was treated with 1 equiv. of CH 2 PPh 3 (0.0828 g, 0.300 mmol) and stirred for 1 h. Upon addition the solution turns red and becomes deeper red over 1 h. Pentane was added to precipitate 6 which was filtered and washed with hexane (Yield = 81%, 0.174 g). Single crystals were grown from a concentrated toluene solution of 6 at 35 C. 1 H NMR (300 MHz, C 6 D 6 (br), 7.02 (s), 3. 53 (s), 3.25 (br), 2.12 (s), 1.41 (s), 1.32 (s), 1.20 (s), 1.10 (s), and 0.85 (s) ppm. Selected IR bands: 3057, 2952, 2913, 2666, 1580, 1549, 1482, 1438, 1410,

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112 1354, 1262, 1116, 1064, 976, 862, 779, and 747 cm 1 Anal. Calcd. for C 45 H 44 CrO 3 7 H 8 ) 2 ; C: 78.73, H: 6.72. Found; C: 78.65; H: 6.77. 3 .4.4 [PPh 3 ] vs. k obs [ t BuOCO]Cr V (O)(THF) (3) in THF Two 25 mL stock solutions of 3 (5.0 mg, 9.8 x10 6 mol) and PPh 3 (70.1 mg, 2.67 x 10 4 mol) in THF were prepared. A reference cell was prepared with 0.8 mL of c hromium solution and 2.2 mL of THF. The reaction cell was prepared by adding 0.8 mL of the chromium solution to the following volumes of THF (mL): 2.0, 1.9, 1.8, and 1.6. The cuvette was chilled to 15 C and the PPh 3 solution was added to the reaction cell via syringe in the respective amounts (mL): 0.2, 0.3, 0.4, and 0.6. The absorbance was monitored at 405 nm for 300 s. 3 .4.5 [OPPh 3 ] vs. k obs. [ t BuOCO]Cr V (O)(THF) (3) in THF A 25 mL THF solution of 3 (8.9 mg, 1.7 x 10 5 mol), a 25 mL THF solution of PPh 3 (63 mg, 2.4 x 10 4 mol), and a 25 mL THF solution of OPPh 3 (63 mg, 2.3 x 10 4 mol) were prepared. The sample cell was prepared using 0.7 mL of the solution containing 3 with 0.0, 0.5, and 1.0 mL of the OPPh 3 solution and the respective amounts of THF (1. 8, 1.3, and 0.8 mL). In addition, a reference cell was prepared in a similar manner with 0.7 mL of the chromium solution with 0.0, 0.5, and 1.0 mL of OPPh 3 solution but with 2.3, 1.8 and 1.3 mL of THF. The PPh 3 solution (0.5 mL) was added to the sample c ell via syringe and the absorbance was monitored at 405 nm for 150 s. 3 .4.6 Variable Temperature. [ t BuOCO]Cr V (O)(THF) in THF A 25 mL stock solution of 3 (14.5 mg, 0.0284 mmol) in THF was prepared. In the sample cell, 0.5 mL of the stock solution was dil uted with 2.0 mL oxygen free THF. A reference cell was prepared in the same matter but with 0.5 mL of the stock solution

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113 and 2.5 mL of oxygen free THF. A 25 mL stock solution of PPh 3 (62.6 mg, 0.239 mmol) in THF was also prepared. 0.5 mL of the PPh 3 solu tion was added to the reaction cell via a syringe and the absorbance was monitored at 405 nm for 300 s. The temperatures for the sample cells were set to 42 C, 20 C, 9 C, and 2 C; addition of 0.5 mL of the room temperature PPh 3 solution resulted in a 1 2 C change in temperature. Every kinetic trial was allowed to go to completion before the temperature was re equilibrated to the initial value. Special considerations were taken for 0 C trials in which a nitrogen filled atmosphere was used to prevent ice formation on the cuvette. Also, for the 10 C trials, periodic wiping of the cuvette was employed to avoid water condensation. 3 .4.7 Solvent Effects. OAT in MeCN, CH 2 Cl 2 and THF A 25 mL stock solution of 3 (16.3 mg, 0.0319 mmol) was prepared in eit her MeCN, CH 2 Cl 2 or THF. In the sample cell, 0.7 mL of the stock solution was diluted with 2.0 mL of the corresponding dry solvent (MeCN, CH 2 Cl 2 or THF). A reference cell was prepared in the same manner with 0.7 mL of the stock solution and 2 mL of dry solvent. A 25 mL stock solution of PPh 3 (50.5 mg, 0.193 mmol) was also prepared, and then 0.3 mL of the PPh 3 solution was added to the reaction cell via syringe and the absorbance was monitored at 405 nm for 300 s. For the CH 2 Cl 2 to obtain clean isosbestic points. 3 .4.8 Substrate Effects. OAT to PMe 3 PPh 3 and P t Bu 3 A 25 mL stock solution of 2 (5.0 mg, 9.78 x 10 5 mol) in THF was prepared. In the sample cell, 0.8 mL of the stock solution was dilu ted with 1.7 mL THF. A reference cell was prepared in the same manner with 2.2 mL of THF. The cells were cooled to and

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114 maintained at 15C. THF solutions of PPh 3 PMe 3 and P t Bu 3 (3.2 mM) were also prepared. The respective phosphine solution (0.5 mL) was ad ded to the sample cell via syringe and the absorbance was monitored at 405 nm for 30 s for PMe 3 300 s for PPh 3 and 12 h for P t Bu 3 3 .4.9 [PPh 3 ] vs k obs : OAT from {[ t BuOCO]Cr IV (THF)} 2 ( O ) (4) to PPh 3 in CH 2 Cl 2 Stock solutions (25 mL) of 4 (47.0 mg, 4.68 x10 5 mol) and PPh 3 (43.5 mg, 1.66 x10 4 mol) in CH 2 Cl 2 were prepared. Sample solutions were prepared using 0.25 mL of 4 by diluting with 2.25 mL, 1.75, and 0.75 mL of CH 2 Cl 2 These s olutions were treated with 0.5, 1.0, and 2.0 mL of PPh 3 respectively, via syringe and the absorbance was monitored at 850 nm for 6 h.

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115 Figure 3 1 General mechanism for substrate oxidation that includes reversible format ion of a M O M intermediate Figure 3 2 EPR spectra (23 C) of recrystallized [ t BuOCO]Cr V (O)(THF) ( 3 ) in toluene (blue, 1.29 mM) and 50:50 THF/CH 2 Cl 2 (orange, 1.5 mM). Figure 3 3 Equilibrium between 3 and 3a

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116 Figure 3 4 Normalized EPR spectra (23 C) of 3 Figure 3 5 Oxygen atom transfer reaction from 3a to PPh 3 Figure 3 6 UV vis spectral change of 3a in THF upon addition of PPh 3 and a plot of [ 3a ] (0.11 mM) vs time (s) upon addition of PPh 3 (1.1 mM) in THF 0 0.5 1 1.5 2 2.5 300 400 500 600 Absorbance Wavelength (nm) 0 2 4 6 8 10 12 0 50 100 150 [3a]x10 5 (M) time (s)

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117 Fig ure 3 7 A plot of ln[ 3a ] vs time. Figure 3 8 Plot depicting first order dependency in [PPh 3 ] (0.71 2.14 mM) for the OAT from 3 a (0.11 mM) at 15 C. Intercept = 0.00(0.01) s 1 ; slope (k 1 ) = 37.8(0.7) mM 1 s 1 -14 -13 -12 -11 -10 -9 -8 0 20 40 60 80 100 ln[3a] time (s) 0 1 2 3 4 5 6 7 8 9 0 0.5 1 1.5 2 2.5 k obs x10 2 (s 1 ) [PPh 3 ] x10 3 (M)

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118 Figure 3 9 Eyring plot for the OAT from 3a (0.186 mM ) to PPh 3 (1.59 mM) in THF between 0 40 C (R 2 = = 9.4(0.8) kcal/mol. Table 3 1 Rate constants for OAT of 3a (0.30 mM) to PMe 3 PPh 3 and P t Bu 3 (0.77 mM) in THF at 15C. d[ 3a ]/dt = k obs [ 3a ] where k obs (s 1 ) = k 1 [phosphine]. PMe 3 PPh 3 P t Bu 3 k obs (s 1 ) 2.45(0.17) x10 1 1.99(0.14) x10 2 8.4(1.9) x10 5 Figure 3 10 Proposed mechanism for OAT. -19 -18 -17 -16 -15 0.003 0.0032 0.0034 0.0036 0.0038 ln (k/T) 1/T (K 1 )

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119 Figure 3 11 Zero order dependency on [OPPh 3 ] (0 1.31 mM) in the OAT from 3 a (0.163 mM) to PPh 3 (1.59 mM) in THF at 22 C. Table 3 2 Rate constants for OAT of 3 (2.97 x10 4 M) to PPh 3 (7.70 x10 4 M) at 22 C. d[ 3 ]/dt = k obs [ 3 ] where k obs = k 1 [PPh 3 ]. CH 2 Cl 2 THF MeCN k obs (s 1 ) 6.9(1.4) x10 2 7.3(1) x10 2 7.4(1.1) x10 2 Figure 3 12 Synthesis of c omplex 6 0 5 10 15 20 0 0.5 1 1.5 k obs x10 2 (s 1 ) [OPPh 3 ] x10 3 (M)

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120 Figure 3 13 Cyclic voltammograms of 3 in CH 2 Cl 2 (red), and 6 in CH 2 Cl 2 (blue) in 0.1 M TBAH/CH 2 Cl 2 at 100 mVs 1 ; glassy carbon working and Ag/Ag + refe rence electrodes. Figure 3 14 Solution EPR spectrum of 6 in hexanes (black) and simulated spectrum using EasySpin.3.1.6. 266 g = 1.982, A( 53 Cr) = 18.58 mT, A( 1 H) = 0.199 mT, and A( 31 P) = 0.066 mT.

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121 Figure 3 15 Molecular structure of [ t BuOCO]Cr V O(CH 2 PPh 3 ) ( 6 ) drawn in two perspectives. Hydrogen atoms and two toluene lattice molecules are omitted for clarity. Figure 3 16 UV vis spectral change of 4 (purple) in CH 2 Cl 2 upon addition of PPh 3 (for reference the UV vis spectra of 2 (green) and 3 ( red) in THF are included).

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122 Figure 3 17 A plot of [ 4 ] (0.16 mM) vs time (s) and ln[ 4 ] vs time upon addition of PPh 3 (1.10 mM) in CH 2 Cl 2 (22C). Figure 3 18 A plot of 4 (1.56 x10 4 M) vs time upon the addition of PPh 3 (1.10 4.42 x10 3 M) in CH 2 Cl 2 (22 C). 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 0 5000 10000 15000 20000 [4] x 10 4 (M) time (s) -14 -13 -12 -11 -10 -9 -8 0 5000 10000 15000 20000 ln[4] time (s) 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 0 5000 10000 15000 20000 [4] x 10 4 (M) time (s) [PPh3] = 1.10E-3 M [PPh3] = 2.21E-3 M [PPh3] = 4.42E-3 M

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123 Figure 3 19 Proposed mechanism of OAT from 43 19 to PPh 3

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124 Figure 3 20 A plot of [ 4 ] (3.11, 1.56, and 0.78 x10 4 M) vs time (s) upon the addition of PPh 3 (1.10 x10 3 M) in CH 2 Cl 2 Figure 3 21 The average 2[ 4 ] [Cr] tot ln[ 4 ] vs time for the addition of PPh 3 (1.1 x10 3 M) into a 3.31 x10 4 M solution of 4 in CH 2 Cl 2 Table 3 3 Si mulated k 1 (s 1 ) and k 1 (M 1 s 1 ) values obtained from the simulation of the [ 3 ] vs time plots. (CH 2 Cl 2 22C) k 1 (s 1 ) k 2 ( M 1 s 1 ) k 1 ( M 1 s 1 ) 8.37(0.81) x10 4 69.5 1.39(0.22) x10 3 0 0.5 1 1.5 2 2.5 3 3.5 0 10000 20000 30000 40000 [4] x 10 4 time (s) [4] = 3.11E-4 M [4] = 1.56E-4 M [4] = 0.78E-4 M 0.0015 0.0016 0.0017 0.0018 0.0019 0.002 0 5000 10000 15000 2 [4] [[Cr] tot ln[4] time (s)

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125 Figure 3 22 Simulated (solid line s) and experimental (dotted lines) of [ 4 ] vs time at different concentration of 4 (0.78, 1.56, and 3.11 x10 4 M). Figure 3 23 Absorption spectrum of 3 (2.36 x10 4 M) in CH 2 Cl 2 (red) and after (9.1 s) addition of PPh 3 (1.87 x10 3 M) to form 4 (red). 0 0.5 1 1.5 2 2.5 3 3.5 0 10000 20000 30000 40000 [4] x 10 4 time (s) Sim [4] = 3.31E-4 M Sim [4] = 1.56E-4 M Sim [4] = 0.78E-4 M [4] = 3.11E-4 M [4] = 1.56E-4 M [4] = 0.78E-4 M

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126 CHAPTER 4 REACTIONS OF AN ONO 3 TRIANIONIC PINCER TYPE TUNGSTEN ALKYLI DYNE WITH ALKYNES AND NIT RILES: PROBING AN UN USUALLY STABLE TUNGSTENABUTADIENE 4 .1 Introduction In C hapter 4 we focus our attention to improving alkyne met athesis catalyst s by using an ONO 3 trianionic pincer ligand Transition metal catalyz ed alkyne cross metathesis 268 272 273 274 279 nitril e alkyne cross metathesis 268, 280 287 ring closing alkyne metathesis 288 291 ring opening alkyne m etathesis polymerization 292 295 and acyclic diyne metathesis 296 298 generate considerable interest as useful synthetic methods to access new R R reagents However, considerable work is still needed to develop catalysts that display similar activity and substrate scope tolerance as their alkene metathesis counterparts. 277, 279 The challenge to increase activity lies in lowering the activation barrier between the alkylidyne and metallacyclobutadiene intermediate ( Figure 4 1). Computational work by Jia and Lin 299 examines the components to the [2+2] cycloaddition activation energy by a series of alkylidyne complexes featuring amido vs. alkoxide ancillary ligands and Mo(VI) vs. W(VI) metals centers. In particular, the authors determined for the transition state of (MeO) 3 that ligand deformation from a trigonal arrangement to T shape geometry ( Figure 4 1) costs ~ 24 kcal/mol The highly energetic transformation is only modestly compensated by the alkyne binding ( ~16 kcal/mol ) 299 Therefore, an ideal catalyst would mitigate t he ligand reorganization energy to lower the [2+2] cycloaddition barrier M. E. O'Reilly, I. Ghiviriga, K. A. Abboud and A. S. Veige, Dalton Trans 2013, 42 3326 3336. Reproduced by permission of The Royal Chemical Society.

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127 In addition to mitigating the activation energy for the forward and reverse [2+2] cycloaddition, the transformation between alky lidyne and metallacyclobutadiene intermediates would ideally be thermoneutral. More concisely, lowering the activation energy of the [2+2] cycloaddition must not come at the expense of a higher barrier for the retro [2+2] cycloadd i tion ( Figure 4 2) Most i mportantly, the reaction must be reversible The stability of a metallacyclobutadiene relative to the alkylidyne precursor is dependent on a combination of steric and electronic contributors. 300 302 Schrock and co workers first demonstrated that poorly basic ancillary ligands stabilize metallacyclobutadienes. 300 302 Som e relevant examples are the tungstenacyclobutadiene W( 2 C 3 R 3 )(OR) 3 with weakly basic alkoxides OC(CF 3 ) 2 CH 3 302 OCH(CF 3 ) 2 302 and OC 6 H 3 ( i Pr) 2 301 In contrast, W( 2 C 3 R 3 )(O t Bu) 3 bearing the strongly basic alkoxide OC(CH 3 ) 3 has never been isolated. In addition, p oorly basic alkoxides lower the [2+2] cycloaddition activation barrier by facilitating alkyne binding to a more electrophilic metal center 299 Using sterically cumbersome alkoxides arguably raises the energy barrier for ligand rearrangement (trigonal T shape) and hinders substrate access, but also serves an important role in destabilizing the corresponding metallacylcobutadiene. For example, W( 2 C 3 Me 3 )(OC(CF 3 ) 2 CH 3 ) 3 will metathesize 20 equiv of 3 heptyne with t 1/2 < ~2.5 min in pentane or diethyl ether, but W( 2 C 3 Me 3 )(OC H (CF 3 ) 2 ) 3 with sterically smaller alkoxides, only slowly converts 3 heptyne in pentane (t 1/2 = 21 h). 302 The slower rate is at tributable to a more stable WC 3 intermediate caused by poor steric repulsion between the alkoxides and the WC 3 ring. Adding donor solvents can compensate and

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128 the rate increases to t 1/2 = 10 min for W(C 3 Me 3 )(OCH(CF 3 ) 2 ) 3 in Et 2 O. Intere for the retro [2+2] cycloaddition of W( 2 C 3 Et 3 )(OCH(CF 3 ) 2 ) 3 is consistent with an associative transition state. 302 Our strategy to improve alkyne met athesis employs trianionic pincer ligands that are rigid and pre organized to adopt a T shape Using a trianionic pincer ligand eliminates the costly ancillary ligand rearrangement energy during the [2+2] cycloadd i tion described by Jia and Lin 299 and will also allow large substrates access to the metal cen ter. Our initial approach was to synthesize a tungsten alkylidyne supported by a trianionic OCO pincer ligand. However, the tungsten alkylidyne carbon is susceptible to insertion into the pincer C W bond. 59 Switching to a trianionic ONO pincer type ligand should prevent any potential insertion chemistry. The [CF 3 ONO] 3 ligand depicted in Figure 4 3 incorporates a push pull 279, 295, 303 306 electronic environment created by pairing an electron rich amido with fluorinated alkoxides which is well known to enhance the activity of alkyne metathesis catalyst 302 Here w e report the syn thesis of the neutral ONO 3 trianionic pincer type tungsten alkylidyne complex [CF 3 t Bu(OEt 2 ) ( 18 ). Moreover, as expected, complex 18 t their respective metallacycles. T he cyclooctyne derivative is the first example of a bicyclic metallacyclobutadiene. However the tungstenacyclobutadienes are remarkably stable and the WC 3 conditions Presented below are their synthesis and characterization, and a discussion regarding the factors promoting their stability.

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129 4 .2 Results and Discussion 4 .2.1 Synthesis and Characterization of [CF 3 ONO]H 3 (8) Our initial approach to preparing an [CF 3 ONO] ligand involved treating bis(2 bromophenyl)amine with three equivalents of n BuLi followed by hexa fluoroacetone addition ( Figure 4 4 ). However, the product could not be realized from a mixture of products. A potential problem was that hexafluoroacetone would undergo electrophilic aromatic substitution at the para position. As such, we decided to protect the para position with a methyl substituent Preparing the ligand precursor [CF 3 ONO]H 3 ( 8 ) involves treating bis(2 bromo 4 methylphenyl)amine 307 with 3.1 equiv of n BuLi in Et 2 O and then adding h exafluoroacetone at 78 C ( Figure 4 5 ). Warming to 25 C and an acidic workup yields isolable proligand 8 in 35% yield. In the 19 F{ 1 H} NMR spect rum of 8 (CDCl 3 ), two broad multiplets attributable to the fluorine atoms appear at 76.3 and 74.9 ppm. The fact two 3 ) 2 OH bond at 25 C. Coalescence of the signals occurs upon heating a sample of 8 to 45 C i n an NMR probe. Routine 1 H and 13 C{ 1 H} NMR spectroscopic techniques corroborate the identity and purity of 8 (A ppendix ). Notable features in the 1 H NMR spectrum include a singlet at 2.36 ppm for the aryl methyl protons, and a broad resonance spanning from 7.0 to 7.5 ppm that corresponds to the protons of the amine and the two alcohol groups. 4 .2. 2 Synthesis and Characterization of [CF 3 ONO]W=CH( t Bu)(O t Bu) ( 9 ) Treating [CF 3 ONO]H 3 ( 1 ) with ( t t Bu 308 in benzene yields complex 9 a tungsten alkylidene supported by a [CF 3 O NO] 3 pincer type ligand ( Figure 4 6 ). Complex 9 crystallizes from a pentane solution at 35 C. The 1 H NMR spectrum of 9 exhibits protons at 1.15 and 1.24 ppm attributable to the W=CHC(C H 3 ) 3 and OC(C H 3 ) 3

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130 protons, respectively. The W=C H t Bu proton resonates at 6.44 ppm with 2 J HW = 8.80 Hz, and the corresponding carbon signal appears at 262.6 ppm in the 13 C{ 1 H} NMR spectrum. The aryl rings of [CF 3 ONO] 3 are unable to lie coplanar rendering the complex C 1 symmetric as exemplified by two separate Ar C H 3 proto n resonances at 1.99 and 1.94 ppm. As a further consequence of the C 1 symmetry, the 19 F{ 1 H} NMR spectrum of 9 contains four quartets, one for each C F 3 group, at 70.7, 71.5, 73.4, and 77.3 ppm. 4 .2. 3 Synthesis and C haracterization of {[CF 3 t Bu )(O t Bu)}{MePPh 3 } ( 10 ) Treating a pentane solution of 9 with Ph 3 PCH 2 deprotonates the alkylidene and precipitates the anionic alkylidyne, complex 1 0 as an analytically pure pink powder ( Figure 4 7 ). The 1 H NMR spectrum of 1 0 contains a doublet at 2.36 ppm ( 2 J HP = 13.31 Hz) corresponding to the H 3 CPPh 3 + counter cation, and the 31 P{ 1 H} spectrum contains a C t Bu carbon resonates downfield in the 13 C{ 1 H} NMR spectrum at 286.0 ppm; and again the 19 F{ 1 H} NMR spectrum reveals the characteristic four quartets indicative of C 1 symmetry at 68.7, 71.2, 74.4, an d 76.2 ppm. 4 .2. 4 In situ S ynthes is of {CH 3 PPh 3 }{[CF 3 t Bu(OTf)} ( 11 ) and [CF 3 t Bu)(OEt 2 ) ( 12 ) Upon treating a benzene solution of complex 1 0 with excess methyl triflate, a color change from red to deep blue occurs over 0.5 h. Evaporating th e solvent under vacuum yields a deep blue oil, which was further purified by dissolving in a minimal amount of benzene and adding dropwise to a cold pentane solution to deposit a deep blue oil of 1 1 Unfortunately, some decomposition occurs, and free [CH 3 P Ph 3 ][OTf] cannot be removed ( Figure 4 8 ). Nonetheless, 1 H, 19 F{ 1 H}, and 2D NMR spectra unambiguously confirm the identity of 1 1 The 1 H NMR spectrum displays one t Bu

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131 proton resonance at 1.07 ppm and two Ar C H 3 proton resonances at 2.10 and 2.07 ppm. The 19 F{ 1 H} NMR spectrum of 1 1 contains four quartets at 69.0, 73.2, 73.9, and 76.7 ppm, and two additional singlet resonances at 76.7 and 78.2 ppm corresponding to coordinated and free OSO 2 CF 3 C t Bu carbon appears at 309.4 ppm in the 13 C{ 1 H } NMR spectrum. For practical reasons, the isolation of 1 1 is not necessary, since dissolving blue 11 in Et 2 O yields a light blue solution of 1 2 and a colorless precipitate of [CH 3 PPh 3 ][OTf] ( Figure 4 8 ). The majority of the [CH 3 PPh 3 ][OTf] can be removed i nitially by filtration, and a small amount precipitates in Et 2 O at 35 C. However, variable amounts of [CH 3 PPh 3 ][OTf] always remain during bulk scale synthesis of 1 2 thus thwarting combustion analysis. The 1 H NMR spectroscopic characterization of 1 2 rev eals one coordinated Et 2 O molecule. The CH 2 protons of th e coordinated ether are diastere otopic, appearing as two multiplets at 3.83 and 3.64 ppm. The t Bu protons resonate at 0.84 ppm, and the two Ar C H 3 protons appear at 2.04 and 2.06 ppm. The 19 F{ 1 H} s pectrum displays the prototypical quartets at 69.2, 71.8, 75.4, and 77.2 ppm. The signa C t Bu carbon appears downfield at 311.5 ppm in the 13 C{ 1 H} NMR spectrum. Blue crystals of 1 2 co crystallize with residual [CH 3 PPh 3 ][OTf] by slowly evaporating a concentrated Et 2 O solution of t he mixture. Depicted in Figure 4 9 is the solid stat e structure of 1 2 The alkylidyne 1 2 contains a tungsten(VI) ion in a square 194 with the [CF 3 ONO] 3 ligand and the coordinated Et 2 O occupying the basal positions ( Figure 4 9 ). The alkylidyne bond sits in the apical position and is nearly linear ( W1 C21 C22 is 171.2(2)) with a W1 C21 bond length of 1.754(3) , consis 1.838

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132 for neutral W(VI) alkylidynes. 295, 300, 304, 305, 309 322 The C 1 symmetry of 18 is apparent in Figure 4 9 by the underlying twist of the [CF 3 ONO] 3 ligand. The nitrogen atom, N1, adopts a planar sp 2 hybridized geometry, evidenced by a 358.8(3) sum of angles around N1. The vector perpendicular to the C3 N1 C13 plane representing the nitrogen lone pair forms 4 .2. 5 Synthesis and C haracterization of [CF 3 ONO]W[ 2 C( t Bu)C(Me)C(Ph)] ( 13 ) Complex 1 2 (or 1 1 3 to yield the tungstenacyclobutadiene complex 1 3 ( Figure 4 10 ). The 1 H NMR spectrum of 1 3 contains the W C 3 C H 3 protons at 2.79 ppm. The protons of the t Bu group shift to 1.21 ppm and the WC 3 C 6 H 5 protons appear between 7.02 and 7.13 ppm. Complex 1 3 is C 1 symmetric yielding four quartets in the 19 F{ 1 H} NMR at 71.5, 72.1, 76.1, and 76.5 ppm, and the 13 C{ 1 H } NMR contains two W C resonances at 245.4 and 243.0 ppm. Crystals were initially grown by slowly evaporating a diethyl ether solution of 1 3 However, crystals more suitable for an X ray diffraction experiment were obtained from a slowly evaporating pentane solution of 1 3 Tab le 4 1 and Table 4 2 list pertinent bond length and angel data. The solid state structure of 1 3 presented in Figure 4 11 contains a tungsten atom in a distorted 194 with the C t Bu (C21) occupying the apical position. The W1 C21 and W1 C23 bond distances are 1.9046(16) and 1.9106(18) , respectively, which are c onsistent with other reported WC 3 rings (Figure 4 12 ). Quite interesting is that the two W C bond lengths are nearly equal, with a difference of only 0.006(3) , whereas other reported structures display a larger difference between the W C bonds, ranging from 0.023 to 0.113 ( Figure 4 12 ). The W1 N1 bond distance is 2.0158(14) and the vector perpendicular

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133 to the C3 N1 C13 plane representing the nitrogen lone pair forms an angle of 42.26 to the WC 3 plane. The phenyl ring (C29 C34) attac hed to the WC 3 ring is forced 44.65 from collinearity with the WC 3 plane. This may be attributed to steric interactions from the nearby WC 3 CH 3 group (C28). An interesting structural feature arising from the constrained pincer type geometry is the O1 W1 O 2 angle of complex 1 3 is tied back resulting in an angle of 147.78(5), which is significantly more acute (10 18) than other crystallographically characterized tungst enacyclobutadienes ( Figure 4 12 ). 301, 302, 30 5, 323 Overall, the WC 3 ring of complex 1 3 contains similar structural features to the other reported WC 3 ri ng moieties depicted in Figure 4 12 To our surprise, complex 1 3 3 to yield any cross metathesis products, even after heating at 200 C, with Et 2 O as a free donor ligand. Despite the seemingly similar electronic features of the [CF 3 ONO] 3 ligand and structural components of the WC 3 ring to reported alkyne metathesis catalysts, complex 1 3 does not undergo retro [2+ 2] cycloaddition. Something unique to the [CF 3 ONO] 3 pincer type ligand must render the tungstenacyclobutadiene fragment exceptionally stable. One possibility is the pincer type ligand, being overly rigid, may prevent the fluxional exchange between the ap ical and equatorial positions within the WC 3 ring as illustrated in Figure 4 13 The solid state structure of 1 3 contains only a single conformer, where t Bu occupies the apical position, but does the [CF 3 ONO] 3 ligand allow a conformer change in solution? Since complex 1 3 contains different groups in position R 1 and R 3 it is impossible to determine if a fluxional process occurs in solution.

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134 However, if the process is fluxional and R 1 = R 3 = t Bu, a single resonance should be present in the 1 H NMR spectrum 4 .2. 6 Synthesis and C haracterization of [CF 3 ONO]W[ 2 C( t Bu)C(Me)C( t Bu)] ( 14 ) Heating complex 1 2 in the presence of t 6 H 6 at 60 C for 3 h yields complex 14 where R 1 and R 3 contain the same t Bu appendage ( Figure 4 10 ). Single crystals suitabl e for X ray diffraction experiments were grown by slowly evaporating an Et 2 O solution of 14 Table 4 1 and Table 4 2 list pertine nt bond lengths and angles and Figure 4 14 depicts the molecular structure. Complex 14 is C 1 symmetric with the tungsten atom a gain i 194 The refined X ray data contains a slight disorder (7%) in the tungsten position. A salient feature in the solid state structure is that the t Bu groups are not equivalent. Evidence includes different W C bond lengths for W1 C21 = 1.882(3) and W1 C23 = 1.908(3) , and different N W C bond angles ( N1 W1 C21 = 122.65(10) and N1 W1 C23 = 154.02(10)). However, the asymmetry only exists in the solid state, because the 1 H NMR spectrum of 14 exhibits a single resonance for both t Bu groups at 1.19 ppm, affirming a fluxional process between the two con formers. The rapid exchange in solution produces an overall C 2 symmetry as evidenced in the 19 F{ 1 H} NMR spectrum of 14 which exhibits only two quartets at 71.9 and 76.5 pm. Similarly, the 13 C{ 1 H} NMR spectrum contains only a single resonance for both C in the WC 3 ring at 252.8 ppm. Despite the increased steric bulk within the WC 3 ring compared to 13 complex 14 again 2 O.

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135 4 .2. 7 Synthesis and C haracterization of [CF 3 ONO]W[ 2 C( t B u)C(CH 2 (CH 2 ) 4 CH 2 )C] (15 ) If thermolysis does not provide the energy necessary to cleave the WC 3 ring, an internal driving force that weakens the WC 3 ring may be necessary. Treating complex 1 2 with cyclooctyne in C 6 H 6 provides complex 15 which contains a W C 3 ring fused to a cyclooctene ( Figure 4 10 ). The internal ring strain within cyclooctene contributes 7.4 kcal/mol 324 directed towards destabilizing the WC 3 unit. The 1 H NMR spectrum of 15 is indicative of a C 1 symmetric complex with six aromatic resonances at 7.69 (s), 7.61 (s) 7.12 (d), 7.10 (d), 6.88 (d), and 6.85 (d) ppm. The Ar C H 3 resonances appear at 2.05 and 2.01 ppm and the t Bu protons resonate at 1.18 ppm. Within the fused cyclooctene structure, the two CH 2 protons adjacent to the WC 3 ring are diastereotopic appearin g as four multiplets at 3.82, 3.66, 3.36, and 3.18 ppm. The remaining CH 2 protons (8H) appear as several broad resonances between 0.90 and 1.55 ppm. The 19 F{ 1 H} NMR spectrum contains four quartets at 70.9, 72.2, 76.1, and 76.6 ppm, and the 13 C{ 1 H} sp ectrum exhibits two unique resonances for W C atoms at 252.8 and 238.6 ppm. Single crystals grow from slow evaporation of a concentrated Et 2 O solution of 15 Table 4 1 and Table 4 2 list pertinent bond lengths and angels and Figure 4 15 depicts the molecu lar structure of 15 The solid state structure consists of a distorted square pyramidal tungsten ion. Attached to the WC 3 ring is a t Bu group (C24 27) and a fused cyclooctene ring (C28 C32). The cyclooctene ring is disordered, containing two different conf ormations at C30 and C31. The C t Bu again occupies the apical position and forms a 123.66(10) bond angle with N1 of the pincer type ligand (N1 W1 C21) while the adjacent N1 W1 C23 bond angle is 153.22(10). The apical W1 C21 bond length of 1.911(3) is slightly longer by 0.014(4) th an the W C23 bond length of 1.897(3) .

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136 Overall the bond lengths and angles about the WC 3 ring within complexes 13 14 and 15 are comparable ( Table 4 1 and Table 4 2 ). Despite the strain imposed by the fused cyclooctene ring, treating complex 15 with d 8 does not yield metathesis products. One salient feature within the molecular structures of 1 3 14 and 15 is the acute O1 W1 O1 bond angles of 147.78(5), 147.39(8), and 147.80(7), respectively. A s a result of this acute angle and the overall pincer type architecture, the CF 3 groups are tied back and prevented from exerting steric pressure on the tungstenacyclobutadiene ring. In contrast are the crystallographically characterized tungstenacyclobut adiene of active alkyne metathesis catalysts ( Figure 4 12 structures A C and D ), where the large ancillary ligands reside over the WC 3 Et 3 ring. As mentioned earlier, the stability of the metallacyclobutadiene complexes depends on the steric repulsion be tween the ancillary ligand and the substituents attached to the WC 3 ring. Consequently, these isolated structures feature small ethyl substituents attached to the tungstenacyclobutadiene ring to minimize the destabilizing steric repulsion. Despite complexe s 13 15 containing larger t Bu substituents, the WC 3 ring is exceptionally inert. For complexes 13 14 and 15 the closest distances between the CF 3 of the pincer type ligand and the WC 3 R groups (R = t Bu, Ph, C 6 H 12 ) are 3.54, 3.52, and 3.53 , respect iv ely. For complex A ( Figure 4 12 ), the closest contact between the CF 3 and the Et group is 3.11 . 305 Considering the poor steric pressure from the [CF 3 ONO] ligand on the WC 3 R 3 rings of 1 3 14 and 15 perhaps adding a stronger donor ligand (e.g. PMe 3 ) will promote retro [2+2] cycloaddition similar to adding Et 2 O to W(C 3 Me 3 )(OCH(CF 3 ) 2 ) 3 302 Treating

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137 complexes 1 3 15 3 as a potential st donor ligand, at 100 C did not generate any metathesis products. Interestingly, a C 6 D 6 solution of complex 13 turns violet upon addition of PMe 3 accompanied by a broadening of protons resonances in the 1 H NMR, but slowly decomposes in solution. T he 1 H NMR spectra of complexes 14 and 15 displayed no signs of reaction with PMe 3 The unusual stability of complexes 1 3 15 prompted us to investigate a possible electronic component to the apparent energetic disparity between 1 3 14 and 15 and a putat ive alkylidyne. 4 .2. 8 Computational Studies Figure 4 16 depicts the geometry optimized structure of both 12 and 13 as calculated by DFT methods. For complex 12 the calculated bond lengths and angles of the tungsten ion core are in good agreement with the crystallographically determined values. For example, the W1 C21 C22 bond angle of 172.35 matches the experimental value of 171.2(2). Similarly, the O1 W1 O2 angle of 143.64 agrees with the experimental value of 144.97(8). The vector perpendicular to the C3 N1 C13 plane representing the nitrogen lone pair is 42.42 from parallel with the tungsten alkylidyne bond (W1 C21). This angle is slightly more acute than the experimental angle of 45. The calculated metric parameters for complex 1 3 are also reas onable, although some bond angle differences deserve mentioning. The N1 W1 C21 angle of 129.77 is 6.78 larger than the crystallographic determined angle of 122.99(7) Correspondingly, the adjacent angle, N1 W1 C23, of 148.39 is smaller by 5.21 than th e experimental value of 153.60(6). These deviations are not uncommon and are observed for other reported WC 3 structures. 304, 305 A more significant deviation is the O1 W1 O2 angle of 155.13 from the experimental angle of 147.78(5). In agreement though, the nitrogen

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138 lone pair represented by a vector perpendicular to the C3 N1 C13 plane forms a 42.75 to the WC 3 ring, matching the experimentally value of 42.26. Quite interesting the molecular structure of 12 fr om single crystal X ray diffraction ( Figure 4 9) and DFT geometry optimization ( Figure 4 17) contain an irregular amido orientation. More precisely, the nitrogen lone pair is prevented from aligning with the low lying d xy constrains the nitrogen lone pair orien t ation ~ bond. The Gaussian single point calculation of complex 12 ( Figure 4 17 ) reveals a unique bonding intera ction between the tungsten alkylidyne bond and the nitrogen lone pair that resembles the electronic bonding structure of enamines In our case, an inorganic version of the enamine, t bond facing the nitrogen (HOMO 2 ) displays overlap with pair, lowering its energy by 0.01822 AU r elative to the bond HOMO 1 Conversely, the nitrogen lone pair in the HOMO forms a destabilizing anti bond. T he electronic consequence of an inorganic enamine will be further di scussed in Chapter 5, but similar to enamines, the nitrogen lone pair serves to increase the nucleophilicity of the carbon To assess the interaction of the inorganic enamine in 1 2 and its fate upon [2+2] c ycloaddition and possible role in preventing retro [2+2] cycloaddition, Gaussian single point calculations were performed on 1 3 Figure 4 17 depicts a truncated molecular orbital diagram of 1 2 with t he inorganic enamine interaction and the frontier MO of 1 3 Analysis of the electronic structure of 1 3 reveals that the inorganic enamine bonding combination within 1 2 is lost. From the single point calculations of 1 3 the

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139 nitrogen lone pair (HOMO) is lower in energy than the HOMO of 1 2 by 0.0155 AU, while the W bonds of 1 3 and 1 2 retain similar energy levels ( 0.22214 and 0.22268 AU, respectively). The N atom lone pair is essentially non bonding. The LUMO xy orbital and p orbitals of the WC 3 ring. The HOMO 1 con tains a d yz overlap with the two C p orbitals of the WC 3 ring. This WC 3 bonding interaction is consistent with other theoretical models. 325 330 Th e HOMO 1 also shows a small amount of bonding overlap with the nitrogen p orbital, though it is unclear whether this interaction contributes much to the stability of 1 3 The most important feature is the restricted orientation caused by chelation, the nitr ogen donate into the LUMO which would destabilize the WC 3 ring by 4 .2. 9 15 N NMR Studies The drastic changes in the nitrogen bonding environment from the alkylidyne complexes of 10 12 and the tungstenacyclobutad iene complexes 1 3 1 5 are evident by 15 N NMR spectroscopy. Table 4 3 lists the 15 N resonances for complexes 9 15 (C 6 D 6 ). The N atom lone pair in the alkylidene complex 9 does not have the appropriate orientation to overlap with the W=C bond, and as a conse quence the lone pair is essentially non bonding. 53 The 15 N resonance for 9 appears downfield at 225.7 ppm. In contrast, the 15 N resonance shifts dramatically upfield to 149.3, 165.5, and 178.3 ppm upon f 1 0 1 1 and 1 2 respectively. Clearly, the N lone dramatic change in the 15 N NMR chemical shift provides experimental evidence for an inorganic enamine orbital interaction. The interaction is lost upon [2+2] cycloaddition to form 1 3 14 and 1 5 From the calculated electronic structure of 1 3 the N atom lone pair

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140 is essentially non bonding, and consequently the 15 N resonance reverts back downfiel d to 208.6 ppm. Similarly, tungstenacycloabutadienes 14 and 15 also exhibit downfield signals at 204.4 and 202.1 ppm, respectively. 4 .2. 10 Electro nic Factors Contributing to an I rreversible [2+2] C ycloaddition The thermodynamic irreversibility of the [2+ 2] cycloaddition products 1 3 14 and 15 is astonishing. As mention ed earlier, complexes 13 15 lack significant steric repulsion between the ancillary ligand and the WC 3 R 3 ring. Unlike the example of W( 2 C 3 Me 3 )(OCH(CF 3 ) 2 ) 3 where poor sterics were compens ated for by adding Et 2 O, 302 donating PMe 3 ligand was not sufficient to break apart the WC 3 ring. Moreover, these results are intriguing since the [CF 3 ONO] 3 ligand incorporates similar electronic features to the fluorinated alkoxides paired with an amido donor, uti lized in 279, 295, 303 305, 322 This leads us to think another factor plays a significant part in the overly stable tungstenacylobutadienes 13 14 and 15 Figure 4 18 depicts the [C F 3 ONO] 3 pincer type ligand where the amido lone pair is 45 from parallel to the tungsten alkylidyne bond ( I ). For comparison, also depicted r either freely rotates ( Figure 4 18 ; II ) 304, 305 or is restricted ( Figure 4 18 ; III ). 304 In both II and III the nitroge n lone pair orients perpendicular to the tungsten alkylidyne bond, thus avoiding the inorganic enamine interaction In case II where the imidazolin 2 iminato ligand can freely rotate, the nitrogen lone pair reorients 90 upon [2+2] cycloaddition to lie co planar to the WC 3 ring. 304, 305 In the case of III the computational models predict that the bulkier tert butyl 3,5 (dimethylphenyl)amido ligand is unable to rotate, remaining perpendicular to the WC 3 plane. 304 Both II and III undergo retro [2+2] cycloaddition.

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141 Thus, one electronic difference between I and cases II and III is II and III are able to avoid the unfavourable inorganic enamine. 4 .2.1 1 Nitrile Alkyne Cross Metathesis As retro [2+2] cycloaddition occurs, the amido alkylidyne interaction turns on according to Figure 4 19 and is endergonic. Removing the amido alkyli dyne interaction should permit facile retro [2+2] cycloaddition. One way to do this is to attempt Nitrile Alkyne Cross Metathesis (NACM). Upon formation of an azametallacyclobutadiene, retro [2+2] cycloaddition have the correct energy match to overlap with the N atom lone pair, and moreover, the sterics remain the same if not somewhat reduced, since the nitrile N atom does not bear a substituent. Indeed, treating complex 12 with excess acetonitrile in C 6 D 6 yields a 57:43 mixture of free 4,4 dimethyl 2 pentyne and 14 along w ith unidentifiable species ( Figure 4 20 ) as evidenced by 1 H NMR. 4,4 Dimethyl 2 pentyne is removed by vacuum and the 1 H and 19 F{ 1 H} NMR spectra unambiguously confirm the identity of 14 The unidentifiable products are presumably tungsten nitrido species, though the identity is not clear from the spectroscopic data. Broad resonances in the 1 H and 19 F{ 1 H} NMR spectra of the reaction mixture may represent several multi nuclear species; it is well known for W nitrido complexes to exist as dimers, 287, 331 334 trimers, 332 335 and larger oligomers. 332, 333 Most importantly, complex 14 and the free 4,4 dimethyl 2 pentyne indicate retro [2+2] cycloaddition occurred. In fact, retro [2+2] cycloaddition must occur swiftly because 14 is the product of alkylidyne 1 2 and free 4,4 dimethyl 2 pentyne.

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142 Adding excess t does not result in any further nitrile alkyne cross metathesis from the presumed tungsten nitrido species. 4 .3 Conclusion Pr esented is the synthesis of a neutral trianionic pincer type tungsten alkylidyne ( 1 2 ). Complex 1 2 t cyclooctyne to form tungstenacyclobutadiene complexes 1 3 14 and 15 respectively. Notably, the synthesis of complex 14 demonstrates the potential advantage of using a trianionic pincer type ligand. Namely sterically cumbersome alkyne ( t ess the metal center to form the metallacyclobutadi ene intermediate at a reasonably low temperature (60 C). Also, c omplex 15 is the first example of a bicyclic metallacyclobutadiene, which is quite remarkable considering cyclooctyne is typically polymeriz ed as a consequence of its internal ring strain. 294, 336, 337 The t ungstenacyclobutadienes 1 3 15 contain bond angles and lengths that are similar to reported single crystal X ray structures of metallacyclobutadiene s from active metathesis catalysts. Regardless of similarities, the complexes 1 3 14 and 15 do not undergo retro [2+2] cycloadd i tion to regenerate the alkylidyne, even at 200 C. Both steric and electronic features push the thermodynamic stability toward s 1 3 14 and 15 from the corresponding alkylidyne. Notably, the chelating nature of the pincer ties back the pendant perflouroalkoxides, preventing the CF 3 groups from exerting steric pressure on the WC 3 core. Surprisingly, adding excess donor ligands suc h as Et 2 O and PMe 3 further supporting an electronic hindrance to retro [2+2] cycloadd i tion DFT calculations reveal the key electronic features within complexes 1 2 and 1 3 Within c omplex 1 2 the N atom lone pair on the pincer forms a bonding and anti

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143 bonding interaction with bond resembling an enamine. Evidence for enamine bonding interaction between N bond comes from 15 N NMR spectroscopy. The 15 N resonance shifts upfield by 47 ppm upon forming the inorganic enamine in the alkylidyne complex 1 2 (178.3 ppm) from the starting alkylidene complex 9 (225.7 ppm) The inorganic enamine interaction is lost upon f orming the tungstenacyclobutadiene 13 and the 15 N NMR reso nance reverts back downfield to 208.6 ppm. Evidence supports that the inorganic enamine interaction is a substantial electronic impediment preventing a reversible [2+2] cycloaddition Proof to support this claim comes from the nitrile alkyne cross metathe sis by complex 1 2 with acetonitrile. Retro [2+2] cycloaddition from the azatungstenacyclobutadiene intermediate forms a combination. ysts. 295, 303 305, 322 Both complexes II and III ( Figure 4 18 ) contains a similar electronic environment of fluorinated alkoxide and amido ligands. However, the inorganic enamine bonding combination is not present, and consequently they are active catalysts. Often in chemical research a ligand purposely designed for a specific application may in fact be incompatible for the process However, the [CF 3 ONO] ligand may be suitable for other applications as featured i n Chapter 5 Nevertheless, these results give us useful information to the design of more appropriate ligand s To remedy these problems associated with [CF 3 ONO] pincer type ligand, c urrent work presented in Chapter 6 features a new ly designed ONO ligand t o destab ilize the

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144 metallacyclobutadiene by increasing the peripheral steric bulk and avoiding any inorganic enamine interactions. 4 .4 Experimental 4 .4.1 General Considerations Unless specified otherwise, all manipulations were performed under an inert atmo sphere using standard Schlenk or glove box techniques. Pentane, hexanes, toluene, diethyl ether, tetrahydrofuran, and acetonitrile were dried using a GlassContour drying column. Benzene d 6 and toluene d 8 (Cambridge Isotopes) were dried over sodium benzoph enone ketyl, distilled or vacuum transferred and stored over 4 molecular si eves. ( t t Bu, 308 cyclooctyne, 338 and Ph 3 PCH 2 339 were prepared according to published procedures. 4 .4.2 Analytical Techniques NMR Techniques: 1 H, 13 C{1H}, and 2D NMR spectra were obtained on an Inova 500 MHz, and the 19 F{ 1 H} and 31 P{ 1 H} were acquired on a Varian Mercury Broad Band 300 MHz (ppm). For 1 H and 13 C{ 1 H} NMR spectra, the residual solvent peak was used as an internal reference. Elemental Analysis: Elemental analyses were performed at Complete Analysis Labo ratory Inc., Parsippany, New Jersey. 4 .4.3 Calculations Geometry optimization, single point analysis, and vibration frequency analysis of 1 2 and 1 3 were performed using spin restricted density functional theory calculations, using a hybrid functional B3LYP 219, 340 and LANL2DZ 341 basis as implemented in the Gaussian 03 program suite. 218 The atomic coordinates from the crystal structures were

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145 used as an initial input for the geometry optimized structures. Molecular orbital pictures were generated from Gabedit 342 at their reported isovalues. 4 .5.4 Synthes is of 2,2' (azanediylbis(3 methyl 6,1 phenylene))bis(1,1,1,3,3,3 hexafluoropropan 2 ol) (8) Inside a nitrogen filled glovebox, an n butyl lithium solution (10.9 mL, 2.5 M, 27.3 mmol) was added drop wise to a Schlenk flask containing a solution of bis(2 bro mo 4 methylphenyl)amine (3.103 g, 8.79 mmol) in diethyl ether (30 mL) at 35 C. The reaction mixture was stirred for 2 h while warming to room temperature. The reaction flask was fitted with a dry ice condenser before exiting the box. The reaction flask was connected to the schlenk line through the port on the dry ice condenser. The reaction solution was cooled to 78 C, and dry ice and acetone were added to the condenser. Hexafluoroacetone was condensed at 78 C (5 mL, 6.6 g, 39 mmol) into a separate p ressure flask. The pressure flask was connected to the reaction flask via the side arm. The pressure flask was allowed to slowly warm to room temperature causing the hexafluoroacetone to evaporate slowly and condense into the reaction flask. After complet e transfer, the pressure flask was removed. The reaction mixture was allowed to warm to room temperature while keeping the dry ice/acetone condenser filled (the hexafluoroacetone will condense on the cold finger and drip back into the solution). The reacti on mixture was stirred for at least 3 h before allowing the dry ice/acetone to expire and the excess hexafluoroacetone leaves through the schlenk manifold. Addition of HCl in Et 2 O (27.3 mL, 1 M) precipitated LiCl from the red solution. The solution was fil tered, and the filtrate was reduced to a thick oil. The thick oil was placed under vacuum for two hours, followed by adding hexanes to precipitate the product. The lightly pink powder was filtered and dried (1.66 g, 35% yield). 1 H NMR (CDCl 3 300 MHz, 25

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146 7.0 (b, 3 H, N H and 2 O H ), 7.37 (s, 2H, Ar H ), 7.17 (d, 2H, 3 J = 8.35 Hz, Ar H ), 8.83 (d, 2H, 3 J = 8.35 Hz, Ar H ), and 2.36 (s, 3H, C H 3 ) ppm. 19 F{ 1 H} NMR (CDCl 3 300 MHz, 25 74.9 (b) and 76.3 (b) ppm. 13 C{ 1 H} NMR (CDCl 3 300 MHz, 25 (s, Ar C ), 134.3 (s, Ar C ), 132.1 (s, Ar C ), 128.5 (s, Ar C ), 126.0 (s, Ar C ) 120.78 9 (s, Ar C ), and 21.0 (s, C H 3 ) ppm. 13 C{ 19 F} NMR(CDCl 3 C F 3 ) and 80.3 (s, Ar(CF 3 ) 2 C OH) ppm. ESI MS: 530.0984 [1+H]+, 552.0803 [1+Na]+, an d 574.0623 [1 H+2Na]+. 4 .4. 5 Synthesis of [CF 3 ONO]W=CH t Bu(O t Bu) ( 9 ) A benzene solution (1 mL) containing 8 (0.324 g, 6.11 x10 4 mol) was added drop wise to a benzene (1 mL) solution of ( t t Bu (0.289 g, 6.11 x10 4 mol). The reaction mixture was allo wed to stir for 1 h before evaporating all volatiles under vacuum for 4 h. The brownish red powder was dissolved in pentane and filtered. The filtrate was collected and concentrated to 3 mL. Cooling the solution to 35 C yields crystals of 9 A second bat ch of crystals was obtained after further concentrating and once again cooling the solution to 35 C. Total yield is 0.350 g (66 %). 1 H NMR (C 6 D 6 ): H ), 7.69 (s, 1H, Ar H ), 6.82 (d, 1H, Ar H 3 J = 8.21 Hz), 6.66 (d, 1H, Ar H 3 J = 8.50 Hz), 6.57 (d, 2H, Ar H 3 J = 8.50 Hz), 6.44 (s, 1H, W=C H t Bu, 2 J ( 1 H, 183 W) = 8.80 Hz), 1.99 (s, 3H, Ar C H 3 ), 1.94 (s, 3H, Ar C H 3 '), 1.24 (s, 9H, O C(C H 3 ) 3 ), and 1.15 (s, 9H, WCHC(C H 3 ) 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 70.71 (q, 3F, CF 3 4 J = 8.48 Hz), 71.52 (q, 3F, CF 3 4 J = 10.90 Hz), 73.44 (q, 3F, CF 3 4 J = 10.90 Hz), and 77.31 (q, 3F, CF 3 4 J = 8.48 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 W C H t Bu), 146.5 (s, Ar C ), 145.4 (s, Ar C ), 134.4 (s, Ar C ), 133.6 (s, Ar C ), 133.0 (s, Ar C ), 131.0 (s, Ar C ), 127.5 (s, Ar C ), 127.3 (s, Ar C ), 126.2 (s, Ar C ), 123.9 (s, Ar C ), 123.5 (s, Ar C ), 90.4 (s, O C Me 3 ), 41.0 (s, WCH C (CH 3 ) 3 ), 35.0 (s, WCHC( C H 3 ) 3 ), 29.2 (s, OC( C H 3 ) 3 ),

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147 21.3 (s, Ar C H 3 C H 3 ) ppm. Anal. Calcd. for C 30 H 33 F 12 NO 3 W (867.41 g/mol): C: 41.54%; H: 3.83%; N: 1.61%, Found; C: 41.42%; H: 3.73; N: 1.59%. 4 .4. 6 Synthesis of {CH 3 Ph 3 P}{[CF 3 t Bu(O t Bu)} ( 10 ) A pentane solution (5 mL) of Ph 3 PCH 2 (0.088 g, 3.19 x10 4 mol) was added drop wise to a stirring pentane solution of 1 0 (0.277 g, 3.19 x10 4 mol) resulting in the precipitation of a pink powder. The mixture was stirred for 4 h and then the pentane layer was decanted from the solid. The solid was stirred in fresh pentane for another 2 h. The solid was collect by filtration and dried under vacuum for 1 h (0.228 g, 80%). 1 H NMR (C 6 D 6 H ), 7.61 (s, 1H, Ar H ), 7.47 (d, 1H, Ar H 3 J = 8.49 Hz), 7.95 7.15 (bs, 16 H, Ar H ), 6.92 (d, 1H, Ar H 3 J = 8.49 Hz), 6.75 (d, 1H, Ar H 3 J = 8.49 Hz), 2.36 (d, 3H, C H 3 PPh 3 2 J HP = 13.31 Hz), 2.14 (s, 3H, Ar C H 3 ), 2.06 (s, 3H, Ar C H 3 '), 1.66 (s, 9H, OC(C H 3 ) 3 ), and 1.17 (s, 9H, WCC(C H 3 ) 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 68.67 (q, 3F, CF 3 4 J = 9.61 Hz), 71.19 (q, 3F, CF 3 4 J = 9.61 Hz), 74.39 (q, 3F, CF 3 4 J = 9.61 Hz), and 76.20 (q, 3F, CF 3 4 J = 9.61 Hz) ppm. 31 P{ 1 H} NMR (C 6 D 6 21.59 (s) ppm. 13 C{ 1 H} NMR (C 6 D 6 C t Bu), 155.5 (s, Ar C ), 154.5 (s, Ar C ), 134.6 (s, Ar C ), 132.5 (s, Ar C ), 131.5 (s, Ar C ), 130.3 (s, Ar C ), 130.2 (s, Ar C ), 130.0 (s, Ar C ), 127.8 (s, Ar C ), 127.2 (s, Ar C ), 127.0 (s, Ar C ), 126. 2 (s, Ar C ), 122.9 (s, Ar C ), 122.6 (s, Ar C ), 121.0 (s, Ar C ), 118.5 (s, Ar C ), 77.1 (s, O C Me 3 ), 49.4 (s, C (CH 3 ) 3 C H 3 ) 3 ), 33.5 (s, OC( C H 3 ) 3 ), 20.7 (s, Ar C H 3 C H 3 ), and 8.5 (d, H 3 CPPh 3, 1 J PC = 57.8 Hz) ppm. Anal. Calcd. fo r C 48 H 48 F 12 NO 3 PW (1129.69 g/mol): C: 51.03%; H: 4.28%; N: 1.24%, Found; C: 50.98%; H: 4.38%; N: 1.18%.

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148 4 .4. 7 Synthesis of {CH 3 PPh 3 }{[CF 3 t 3 PPh 3 }{OTf} (11 ) Benzene solutions (2 mL) of 1 0 (0.201 g, 1.78 x10 4 mol) and MeOTf (0.040 g, 2 .44 x10 4 mol) were mixed together and stirred for 0.5 h. The solvent was removed in vacuo and the resulting residue dried for 1 h under vacuum. The residue was then dissolved in minimal benzene and added drop wise into a cold pentane solution to form an o ily dark blue precipitate which was collected by filtration (2x). The collected precipitate was dried under vacuum to yield a dark blue powder containing 11 and inseparable {CH 3 PPh 3 }{OTf}. Isolated yield was 0.1162 g (approximate yield 50% based on W). 1 H NMR (C 6 D 6 H ), 7.68 (s, 1H, Ar H ), 7.32 (d, 1H, Ar H 3 J = 8.24 Hz), 7.25 7.00 (bs, ~30 H, Ar H ), 6.97 (d, 1H, Ar H 3 J = 8.65 Hz), 6.90 (d, 1H, Ar H 3 J = 8. 24 Hz), 6.80 (d, 1H, Ar H 3 J = 8. 65 Hz), 2.29 (d, ~4.75 H, C H 3 PPh 3 2 J HP = 13.31 Hz), 2.10 (s, 3H, Ar C H 3 ), 2.07 (s, 3H, Ar C H 3 '), and 1.07 (s, 9H, WCC(C H 3 ) 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 68.98 (q, 3F, CF 3 4 J = 8.48 Hz), 73.18 (q, 3F, CF 3 4 J = 8.48 Hz), 73.93 (q, 3F, CF 3 4 J = 9.69 Hz), 76.64 (q, 3F, CF 3 4 J = 9.69 Hz ), 76.68 (s, 3F, W OSO 2 CF 3 ), and 78.20 (s, 1.29 F, free 0.5 OTf) ppm. 31 P{ 1 H} NMR (C 6 D 6 21.98 (s) ppm. 13 C{ 1 H} NMR (C 6 D 6 C t Bu), 152.4 (s, Ar C ), 151.4 (s, Ar C ), 135.5 (s, Ar C ), 134.7 (s, Ar C ), 132.6 (s, Ar C ), 130.8 (s, Ar C ), 130.6 (s, Ar C ), 130.0 (s, Ar C ), 127.5 (s, Ar C ), 127.1 (s, Ar C ), 126.2 (s, Ar C ), 121.1 (s, Ar C ), 120.1 (s, Ar C ), 118.6 (s, Ar C ), 118.0 (s, Ar C C (CH 3 ) 3 C H 3 ) 3 ), 20.7 (s, Ar C H 3 C H 3 ) and 8.3 (d, H 3 C PPh 3, 1 J PC = 57.8 Hz) ppm. 4 .4. 8 Synthesis of [CF 3 t Bu)(OEt 2 ) ( 12 ) Complex 1 1 (0.1162 g) was dissolved in diethyl ether (2 mL). The solution changes from dark blue to light blue and a white precipitate formed. The white solid was removed by filtration. C ooling the filtrate precipitates additional white solid, which was

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149 subsequently removed via decanting. Slow evaporation of the diethyl ether solution yielded blue crystals of 1 2 suitable for single crystal X ray diffraction concomitant with inseparable {CH 3 PPh 3 }{OTF}. Isolated yield was 0.080 g. In C 6 D 6 the free OTf coordinates and displaces diethyl ether. 1 H NMR (C 6 D 6 H ), 7.69 (s, 1H, Ar H ), 7.10 (d, 1H, Ar H 3 J = 8.21 Hz), 7.01 (d, 1H, Ar H 3 J = 8.21 Hz), 6.74 (s, 2H, Ar H ), 3.89 3.78 (m, 2H, O(C( H 3 ) 2 ), 3.71 3.58 (m, 2H, O(C(H)( H 3 ) 2 ), 2.06 (s, 3H, Ar C H 3 ), 2.05 (s, 3H, Ar C H 3 '), 0.8 9 (t, 6H, O(CH 2 C H 3 ) 2 ), and 0.085 (s, 9H, WCC(C H 3 ) 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 69.23 (q, 3F, CF 3 4 J = 8.48 Hz), 71.80 (q, 3F, CF 3 4 J = 9.69 Hz), 75.43 (q, 3F, CF 3 4 J = 9.69 Hz), and 77.19 (q, 3F, CF 3 4 J = 8.48 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 311.5 (s, W C t Bu), 151.0 (s, Ar C ), 150.5 (s, Ar C ), 135.3 (s, Ar C ), 132.5 (s, Ar C ), 131.3 (s, Ar C ), 131.0 (s, Ar C ), 128.7 (s, Ar C ), 127.5 (s, Ar C ), 126.8 (s, Ar C ), 122.3 (s, Ar C ), 119.3 (s, Ar C ), 79.2 (s, O( C H 2 CH 3 ) 2 ), C (CH 3 ) 3 ), 33.6 ( C H 3 ) 3 ), 20.6 (s, Ar C H 3 C H 3 ) and 13.4 (s, O(CH 2 C H 3 ) 2 ) ppm. 4 .4. 9 Synthesis of [CF 3 ONO]W[ 2 C( t Bu)C(Me)C(Ph)] ( 13 ) A diethyl ether solution of 10 (0.139 g, 1.23 x10 4 mol), MeOTf (0.020 g, 1.23 x10 4 .23 x10 4 mol) was allowed to stir overnight. The solution was filtered and the filtrate reduced. The resulting oily residue was dissolved in pentane, filtered, and the filtrate was reduced under vacuum. The residue was taken up in Et 2 O and slow evaporatio n yielded crystals of the product. The crystals were rinsed quickly with pentane and dried (0.058 g, 51%). Crystals suitable for X ray diffraction experiments were grown by recrystallizing the material above via a slow evaporation of a pentane solution. 1 H NMR (C 6 D 6 H ), 7.61 (s, 1H, Ar H ), 7.02 7.13 (m, 6H, Ar H ), 6.90 (d, 1H, Ar H 3 J = 7.55 Hz), 6.87 (d, 1H, Ar H 3 J = 8.10 Hz), 6.80 (d,

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150 1H, Ar H 3 J = 8.51 Hz), 2.76 (s, 3H, WC 3 C H 3 ), 2.00 (s, 3H, Ar C H 3 ), 1.98 (s, 3H, Ar C H 3 '), 1.18 (s, 9H, W CC(C H 3 ) 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 71.49 (q, 3F, CF 3 4 J = 9.69 Hz), 72.07 (q, 3F, CF 3 4 J = 9.69 Hz), 76.06 (q, 3F, CF 3 4 J = 9.69 Hz), and 76.53 (q, 3F, CF 3 4 J = 9.69 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 C ), 242.3 (s, W C ), 146.0 (s, Ar C ), 144.9 (s, Ar C ), 138.2 (s, WC 2 C ), 138.2 (s, Ar C ), 132.4 (s, Ar C ), 131.9 (s, Ar C ), 131.9 (s, Ar C ), 129.9 (s, Ar C ), 129.2 (s, Ar C ), 128.3 (s, Ar C ), 127.7 (s, Ar C ), 127.3 (s, Ar C ), 127.1 (s, Ar C ), 126.9 (s, Ar C ), 124.9 (s, Ar C ), 124.5 (s Ar C ), 42.3 (s, WC 3 C (CH 3 ) 3 ), 30.2 (s, WC 3 C( C H 3 ) 3 ), 20.4 (s, Ar C H 3 ), 20.3 (s, Ar C H 3 '), and 15.8 (s, WC 3 C H 3 ) ppm. Anal. Calcd. for C 35 H 31 F 12 NO 2 W (909.45 g/mol): C: 46.22%; H: 3.44%; N: 1.54%, Found; C: 46.31%; H: 3.50%; N: 1.60%. 4 .4. 10 Synthesis of [CF 3 ONO]W[ 2 C( t Bu)C(Me)C( t Bu)] (14 ) A C 6 D 6 solution of 4,4 dimethyl 2 pentyne (0.018 g, 1.9 x10 4 mol) and complex 12 that was generated in situ from 10 (0.183 g, 1.62 x10 4 mol) and MeOTf (0.027 g, 1.7 x10 4 mol), was heated in a J young tube at 60 C for 3 h. T he solvent was removed in vacuo. The solid residue was dissolved in Et 2 O (1 mL) and precipitated by the addition of hexanes to yield a purple powder. The solid was removed by filtration and the filtrate was reduced to give a brown powder. The powder was qu ickly rinsed with pentanes, and then dissolved in Et 2 O. Slow evaporation of the ether solution yielded brown crystals of 14 (0.068 g, 47 %). 1 H NMR (C 6 D 6 H ), 7.06 (d, 2H, Ar H, 3 J = 8.37 Hz), 6.84 (d, 2H, Ar H, 3 J = 8.37 Hz), 2.97 (s, 3H, WC 3 C H 3 ), 2.00 (s, 6H, Ar C H 3 ), and 1.19 (s, 18 H, WC 3 C(C H 3 ) 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 71.87 (q, 3F, CF 3 4 J = 9.69 Hz) and 76.53 (q, 3F, CF 3 4 J = 9.69 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 C ), 146.4 (s, Ar C ), 139.0 (s, WC 2 C ), 132.9 (s, Ar C ), 132.6 (s, Ar C ), 128.9 (s, Ar C ), 127.3 (s, Ar C ), 125.6 (s, Ar C ), 43.3 (s, WC 3 C (CH 3 ) 3 ), 30.9 (s,

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151 WC 3 C( C H 3 ) 3 ), 21.1 (s, Ar C H 3 ), and 12 .3 (s, WC 3 C H 3 ) ppm. Anal. Calcd. for C 33 H 35 F 12 NO 2 W (909.45 g/mol): C: 44.56%; H: 3.97%; N: 1.57%, Found; C: 44.45%; H: 4.08%; N: 1.57%. 4 .4.1 1 Synthesis of [CF 3 ONO]W[ 2 C( t Bu)C(CH 2 (CH 2 ) 4 CH 2 )C] ( 15 ) A diethyl ether solution of cyclooctyne (0.040 g, 3 .7 x10 4 mol) was added to an Et 2 O solution containing complex 12 that was generated in situ from 10 (0.213 g, 1.89 x10 4 mol) and MeOTf (0.070 g, 4.27 x10 4 mol). The solution was stirred for 0.5 h and the solution changed color from blue to red brown. Th e solution was filtered and reduced to provide an oily solid. The residue was dissolved in pentanes and filtered. Slow evaporation of the pentane filtrate yielded crystals of 15 The solution was decanted from the crystals and the collected material was re crystallized a second time from a slow evaporating diethyl ether solution (0.065 g, 38%). 1 H NMR (C 6 D 6 (s, Ar H ), 7.61 (s, Ar H ), 7.12 (d, 1H, Ar H 3 J = 7.82 Hz), 7.10 (d, 1H, Ar H 3 J = 7.69 Hz), 6.88 (d, 1H, Ar H 3 J = 8.37 Hz), 6.85 (d, 1H, Ar H 3 J = 8.51 Hz), 3.82 (dt, 1H, WC 3 C( H )(H') R, 2 J = 11.67 Hz, 3 J = 4.80 Hz), 3.66 (m, 1H, WC 3 [C(H)( H ')(C H 2 ) 4 CH 2 ]), 3.36 (m, 1H, WC 3 [CH 2 (C H 2 ) 4 C( H )(H')]), 3.18 (m, 1H, WC 3 C(H)( H ') R), 2.05 (s, 3H, Ar C H 3 ), 2.01 (s, 3H, Ar C H 3 '), 1.18 (s, 9H, WC 3 C(C H 3 ) 3 ), and 0.90 1.55 (bs, 8H, WC 3 [CH 2 (C H 2 ) 4 CH 2 ]) ppm. 19 F{ 1 H} NMR (C 6 D 6 70.92 (q, 3F, CF 3 4 J = 9.69 Hz), 72.22 (q, 3F, CF 3 4 J = 9.69 Hz), 76.06 (q, 3F, CF 3 4 J = 9.69 Hz), and 76.56 (q, 3F, CF 3 4 J = 9.69 Hz) ppm. 13 C{ 1 H} = 252.8 (s, W C ), 238.6 (s, W C ), 145.1 (s, Ar C ), 144.6 (s, Ar C ), 142.8 (s, WC 2 C ), 132 .4 (s, Ar C ), 132.0 (s, Ar C ), 131.9 (s, Ar C ), 131.4 (s, Ar C ), 127.3 (s, Ar C ), 126.9 (s, Ar C ), 126.0 (s, Ar C ), 125.8 (s, Ar C ), 125.0 (s, Ar C ), 124.2 (s, Ar C ), 42.0 (s, WC 3 C (CH 3 ) 3 ), 35.5 (s, WC3 [ C H 2 (CH 2 ) 4 CH 2 ]), 31.0 (s, WC 3 C( C H 3 ) 3 ), 31.0 (s, WC3 [CH 2 ( C H 2 ) 4 CH 2 ]), 29.5 (s, WC3 [CH 2 ( C H 2 ) 4 CH 2 ]), 26.9 (s, WC3

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152 [CH 2 (CH 2 ) 4 C H 2 ]), 26.0 (s, WC3 [CH 2 ( C H 2 ) 4 CH 2 ]), 24.0 (s, WC3 [CH 2 ( C H 2 ) 4 CH 2 ]), 20.4 (s, Ar C H 3 ), and 20.3 (s, Ar C H 3 ') ppm. Anal. Calcd. for C 34 H 35 F 12 NO 2 W (901.47 g/mol): C: 45.30%; H: 3.91%; N: 1.5 5%, Found; C: 45.31%; H: 3.97%; N: 1.56%.

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153 Figure 4 1 Ancillary ligand rearrangement during alkyne metathesis. Figure 4 2 D elicate balance of lowering activation energy while keeping the alkylidyne and metallacyclobutadiene thermoneutral. Figure 4 3 The push pull electronic effect of the [CF 3 ONO] pincer type l i gand and the inorganic e namine bonding structure

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154 Figure 4 4 Initial proposed synthesis of an [CF3 ONO] ligand. Figure 4 5 S ynthesis of 8 Figure 4 6 Synthesis of 9 Figure 4 7 Synthesis of 10

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155 Figure 4 8 Synthesis of 1 1 and 1 2 Figure 4 9 Molecular structure of [CF 3 t Bu)(OEt 2 ) ( 1 2 ) with ellipsoids drawn at 50% Probability level, with hydrogens removed for clarity. Only one of two disordered c onformation s at C28 is shown for clarity.

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156 Figure 4 10 Synthesis of tungstenacyclobutadienes 1 3 14 and 15

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157 Figure 4 11 Molecular structure of [CF 3 2 C( t Bu)C(Me)C(Ph)] ( 19 ) with ellipsoids drawn at 50% probability level, with hydrogens removed for clarity. Figure 4 12 Reported X 2 C 3 Et 3 ) (ImN){OCMe(CF 3 ) 2 } 2 ( A ), 305 2 C( t Bu)C(Me)C(Me)]Cl 3 ( B ), 323 2 C 3 Et 3 )[O 2,6 C 6 H 3 ( i Pr) 2 ] 3 ( C ), 301 2 C 3 Et 3 )[OCH(CF 3 ) 2 ] 3 ( D ), 302 19 20 and 21

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158 Table 4 1 Selected metric parameters for the WC 3 rings of 19 20 and 21 Bond length() 19 20 21 W1 C21 1.9046(16) 1.882(3) 1.911(3) W1 C23 1 .9106(18) 1.908(3) 1.897(3) C21 C22 1.450(3) 1.456(4) 1.443(4) C22 C23 1.473(2) 1.453(4) 1.473(4) W1 N1 2.0158(14) 2.022(2) 2.023(2) Table 4 2 Selected metric parameters for the WC 3 rings of 19 20 and 21 Bond angle() 19 20 21 N1 W1 C21 122.99(7) 122.65(10) 123.66(10) N1 W1 C23 153.60(6) 154.02(10) 153.22(10) O1 W1 O2 147.78(5) 147.39(8) 147.80(7) Figure 4 13 Fluxional WC 3 ring conformations. W N W R 3 R 2 R 1 O O W N W R 1 R 2 R 3 O O

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15 9 Figure 4 14 Molecular structure of [CF 3 ONO]W[C( t Bu)C(Me)C( t Bu)] ( 14 ) with ellipsoids drawn at 50% probability level, with hydrogens removed for clarity. A disordered W ion position (7%) is removed for clarity. Figure 4 15 Mo lecular structure of [CF 3 ONO]W[C( t Bu)C(CH 2 ) 6 C] ( 15 ) with ellipsoids drawn at 50% probability level, with hydrogens removed for clarity. Only one of two disordered conformation at C30 and C31 are shown for clarity.

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160 Figure 4 16 DFT geometry optimized structures of 1 2 and 1 3 with calculated bond lengths (red) and crystallographic determined lengths (black).

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161 Figure 4 17 Truncated MO diagram of 1 2 and 1 3 (isovalues = 0.051687).

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162 Table 4 3 15 N NMR chemical shifts of 9 15 9 1 0 1 1 1 2 1 3 14 15 ppm 225.7 149.3 165.5 178.3 208.6 204.4 202.1 Figure 4 18 Amido lone pair orientation for varying ligand systems of tungsten alkylidyne and tungstenacyclobutadiene complexes ( I II 304, 305 and III 304 ).

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163 Figure 4 19 Reaction progress vs free energy diagram for retro [2+2] cycloaddition. Figure 4 20 Nitrile alkyne cross metathesis upon treating 18 with MeCN.

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164 CHAPTER 5 AN ONO 3 TRIANIONIC PINCER TYPE LIGAND FOR GENE RATING HIGHLY NUCLEOPHILIC METAL CARBON MULTIPLE BOND S: AN INORGANIC ENAM INE 5.1 Introduction In Chapter 4 we introduced the trianionic ONO pincer type ligand supported tungsten alkylidyne. Unfortunately, the complex when treated with an alkyne stops at the c ycloaddition intermediate and fails to catalyze alkyne metathesis Contributing to the large thermodyn amic gradient preventing a needed reversible cycloaddtion is the loss of the reactive inorganic enamine interac tion between the amido lone pair and the upon cycloaddition Still th e [CF 3 ONO] ligand may serve other useful purposes. In one aspect, the inorganic enamine interaction offers the potential to increase the nucleophilicity of metal liga nd multiple bond s which can be utilized for the purposes of C H bond activation. Here we discuss more fully the concept of an inorganic enamine and provide examples that demonstrate this reactivity. Metal ligand multiple bonds featuring groups 4 and 5 t ransition metals ( especially the first row derivatives) have a significant ionic component 343 347 A simple explanation for this phenonmena is that early transition metals are considerably electropositive, while a more descriptive explanation would take into account the mismatch ed atomic orbital energies of the metal d orbitals relative to the low lying ligand counterpart. As a result of the significantly polarized bo nding the electron density accumulate s on the alkylidyne ligand. The additional electron density is well received by electr onegative atoms as oxygen but less so by carbon which becomes highly nucleophilic. 343, 344 347 349 Superlative examples of the nucleophilic reactivity include the Adapted with permission from M. E. O'Reil ly, I. Ghiviriga, K. A. Abboud and A. S. Veige, J. Am. Chem. Soc. 2012, 134 11185 11195. Copyright 2012 American Chemical Society.

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165 alkyl 2 Ti( CH 2 )( X)Al(CH 3 ) 2 (X = Cl, Me) 350 353 C t Bu) 280, 354 362 and vanadium ([nacnac]V C t Bu) alkylidynes. 363, 364 Recently, Mindiola and coworkers h a ve harnessed the nucleophilicity of a titanium alkylidyne to activate the inert C H bond of methane 354 A drastic change in the nucleophilicity of the M C multiple bond occurs upon moving from group 4 to group 6 metal complexes G roup 6 metal carbon multiple bonds 276 of molybdenum (VI) and tungsten (VI) are more covalent and correspondingly less nucleophilic 343, 345 347 As a result, these complexes are well suited for alkene and alkyne metathesis. A challenge from an organometallic perspective is to develop methodologies that fine tune the nucleophilic i ty of the M C multiple bonds, with minimal disturbance to the selected metal center. The appropriate anci llary ligand design provides the possibility of control ling the electronic structure of M C multiple bonds to create highly nucle ophilic species. Methodologies that accentuate the nucleophilicity of metal ligand multiple bonds ar e useful for 1,2 C H activation and other inert bond activation s Herein, we present a rational approach to creating tungsten carbon multiple bonds with hig h nucleophilicity at the carbon by employing a push pull strategy that employs an inorganic enamine bonding concept for the push. To create a highly nucleophilic polarized metal carbon bond, the ancillary ligand must polarize the M C multiple bond. In ot her words, the ligand must induce an electrophilic metal center while pushing electron density carbon, a so called push pull effect. 365 However, simply in ducing an electronically starved metal serves to carbon by forming a more covalent M C multiple

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166 bond. The challenges in polarizing the M C multiple bond lies in accumulating electron carbon while remov ing it from the metal center. Some of the most highly active alkene 366, 367 and alkyne 279, 295, 303 306 metathesis catalysts employ a push pull idea by pairing an electron rich imi do or amido ligand coupled with donating fluorinated alkoxides ( OC(CF 3 ) 2 CH 3 ). The fluorinated alkoxides are poorly basic and create an electro philic metal, but the role of the imido or amido is not as clear. 304, 368 For monodentate amido ligands, the lon e pair on the nitrogen pre ferably orients perpendicular to the metal carbon multiple bond and donates into a low lying vacant d xy orbital which operates against the goal to create an electrophilic metal ion ( Figure 5 1) 303 305, 369 371 To avoid this, the [CF 3 ONO] ligand purposely orient s the amido lone pair coll inear or closely aligned with the metal carbon bond axis ( Figure 5 1 ). The result ing bonding interaction is what we term an inorganic enamine. Appending an amine to an olefin yields a so called enamine The reactivity of enamine s was originally developed by Stork and coworkers in Stork enamine alkylation reactions, 372 374 which more recently has been expanded beyond stoichiometric reactions to organocatalysis. 375 379 Within the enamine bonding structure, the nitrogen carbon. A simple resonance structure depiction helps to explai n the observed increased nucleophilicity ( Figure 5 2 ) 373, 374 The nitrogen through resonance structure to the carbon atom two bonds away. In principle, replacing the alkene with a me tal alkylidene (M=C) should yield a similar bonding interaction that increases the n ucleophilicity of the

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167 carbon. Hence, e mploying the enamine bonding concept to metal ligand multiple bonds may lead to exciting new reactivity A better understanding of the electronic structure within an enamine and/or inorganic enamine requi res a molecular orbital diagram. In both examples, the N atom lone pair forms a bonding and antibonding combination with the C=C bond or in the case of alkylidenes, the M=C bond ( Figure 5 3 ). The energetic consequence is two fold. T he bonding electr ons in the HOMO ( 1) are stabilized by additional overlap with the N orbital, while the nitrogen lone pair (HOMO) forms a destabilizing anti bonding bond. A second important feature is the size of e ach atomic orbital contribution in t he HOMO. As noted earlier, the nitrogen lone pair pushes electron density two bonds away. This property is evident in the HOMO; the appended carbon atom or the metal center has low contributions to the molecular orbital carbon is exceptionally larger This effect carbon, while concurrently retaining an electron deficient metal ion. As mentioned earlier, t he challenge for synthesizing an inorganic enamine is that the unrestricted amido ligand will orient th e lone pai r perpendicular to the M C bond ( Figure 5 1 ). M ultidentate ligand s offer the possibility to constrain the amido lone pair orientation Trianionic NCN 27 30 and OCO 3 1 42 pincer ligands are excellent examples of a rigid meridional environment and have been utilized for catalytic aerobic oxidation, 36 alkene isomerization 28 and polymerization, 27, 42 alkyne polymerization, 31 and fundamental transformations 34 involving oxygen atom transfer, 32 nitrogen atom transfer, 38 and dioxygen activation. 33 In addition, Heyd uk et al. introduced redox active trianionic ONO 3 NNN 3 and SNS 3 pincer type ligands. 45 52, 55, 58 Figure 5 4 depicts a

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168 CF 3 ONO 3 pincer type ligand that incorporates all the essential design features needed to create a highly nucleoph ilic metal carbon multiple bond T he fluorinated alkoxides induce an electrophilic metal centre (pull); the constrained pincer framework prevents donation into the d xy orbital, and instead the lone pair interacts with the m etal carbon bond (push). Accomplishing this objective, we now present a rationally designed trianionic pincer type ligand that increases the nucleophilicity of a tungsten alkylidene [CF 3 ONO]W=C(Et)(O t Bu) ( 16 ) and a alkylidyne {MePPh 3 }{[CF 3 O t Bu)} ( 1 7 ). Demonstrating high nucleophilicity, addition of a Me 3 SiOTf to 16 and 1 7 expels isobutylene in an intramolecular C H bond activation pathway. 5 .2 Results 5.2.2 Synthesis and Characterization of [CF 3 ONO]W=CH(Et)(O t Bu) ( 16 ) In benzene, combinin g proligand 8 with ( t BuO) 3 W C(Et) 286 results in the immediate formation of the trianionic pincer alkylidene complex [CF 3 ONO]W=CH(Et)(O t Bu) ( 16 ) according to Figure 5 6 Isolation of reasonably pure 16 only requires remov al of all volatiles in vacuo; re crystallizing 16 in pentane provides analytically pure material. Single cr ystals amenable to an X ray diffraction experiment deposit upon cooling a concentrated pentane solution of 16 to 35 C. Structure refinement of the diffraction data provides the molecular structure of 16 presented in Figure 5 7 Complex 16 is C 1 symmetric and occupying the basal plane of the distorted square pyramidal tungsten(VI) geometry are the ONO 3 trianionic pincer ligand and tert butoxide. In the apical position resides a propylidene ligand with a W C bond length of 1.882(4) , which is consistent with a double bond and similar to two other OCO 3

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169 trianionic pincer W alkylidenes that have bond lengths of 1.887 and 1.913 . 35 Consistent with a W=C double bond, the 13 C{ 1 H} NMR spectrum of 16 contains a downfield resonance at 260.3 ppm ( 1 J( 13 C, 183 W) = 173.1 Hz) and the corresponding alkylidene proton (W=C H R) resonates as a triplet at 7.36 ppm. An interesting structural feature appears in the trianionic pincer ligand framework. Unable to lie coplanar, the N aryl rings twist, thereby lowering the solid state symmetry from potentially C s to C 1 This twist and resulting low symmetry persists in solution as four distinct quartets appear in the 19 F NMR spectrum of 16 at 71.2, 71.5, 73.9, and 77.2 ppm. The low symmetry also results in diastereotopic C H 2 methylene protons for the propylidene ligand that appear as two multiplets at 5.08 ppm and 4.79 ppm. The propylidene methyl appears as a triplet at 0.77 ppm ( 3 J = 7.36 Hz). The nitrogen atom of the ONO ligand is trigonal planar (sum of angles = 359.6( 4)), consistent with sp 2 hybridization. The alkylidene bond orients as the anti isomer and does not rotate with an appreciable rate even at 100 C. No signals attributable to an exchange with the syn isomer appear in variable temperature 1 H NMR spectra of 16 from 60 C to 100 C. In syn isomer predominantly forms (K syn/anti = 5000), but access to the anti isomer is possible by exposing a sample to UV radiation at 85 C for several hours. 380 The relaxation of the anti isomer back to syn occurs between 53 C to 38 C. 380 Interestingly, the rate of relaxation decreases as the alkoxide ligands become more fluorinated. 381 Invoking similar conditions for complex 9 a toluene d 8 solution of 9 exposed to 366 nm light for 4 h at 78 C does not yield any detectable syn isomer as determined by 1 H NMR (500 MHz) spectroscopy.

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170 5.2.3 Synthesis and C haracterization of {[CF 3 t Bu)}{MePPh 3 } (1 7 ) Deprotonating alkylidenes with methylenetriphenylphosphorane (Ph 3 P=CH 2 ) is a convenient meth od to access the corresponding alkylidyne anion. 339 Treating alkylidene 16 with Ph 3 P=CH 2 in pentane at 25 C precipitates the W alkylidyne anion 1 7 ( Figure 5 8 ). Complex 17 turns to a bright red color upon dissolving in benzene or ether. Removing the sol vent by vacuum yields a red oil, but the addition of cold pentane returns 17 to a yellow powder. Multinuclear 1 H 13 C gHSQC and 1 H 13 C gHMBC NMR spectroscopic experiments confirm the identity of 1 7 and permit the absolute assignment of all resonances in the 1 H and 13 C{ 1 H} NMR spectra ( Appendix ). Most pronounced is the downfield shift to 280.6 ppm for the W C alkylidyne carbon in the 13 C{ 1 H} NMR spectrum. In the 1 H NMR spectrum, a doublet ( J HP = 13.31 Hz) at 2.44 ppm is attributable to the methyl protons of the phosphonium counter cation, and the corresponding phosphorus resonates at 21.8 ppm in the 31 P{ 1 H} NMR spectrum. Consistent again with a C 1 symmetric complex, the 19 F NMR spectrum contains four distinct quartets at 69.38, 71.24, 74.08, and 76.38 ppm. 5.2.4 Reactivity S tudies, N ucleophilic at C arbon Adding methyl triflate to 1 7 in a sealable NMR tub e results in alkylation of the alkylidyne carbon to form [CF 3 ONO]W=C(Me)(Et)(O t Bu) ( 1 8 ) ( Figure 5 9 ). Confirming the identity of 1 8 a 1 H NMR spectrum of the reaction mixture reveals a resonance attributable to the newly formed methyl protons (W=C(C H 3 )Et) at 4.90 ppm (3H). The C H 2 methylene protons are diastereotopic, resonating as two sets of multiplets at 4.65 and 4.53 ppm, similar to complex 16 The O t Bu protons resonate at 1.21 ppm (9H). The W C resonates at 284.3 ppm, consistent with other report ed tungsten dialkyl

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171 substituted alkylidenes. 382 384 The 1 H 13 C gHMBC spectrum of 1 8 confirms the connectivity among the methyl protons at 4.90 ppm, the diastereo topic methylene protons at 4.65 and 4.53 ppm, and the alkylidene carbon. Unidentifiable and inseparable minor impurities precluded the large scale purification of 1 8 5.2.5 Isobutylene E xpulsion from 1 7 Adding the larger electrophile Me 3 SiOTf to complex 1 7 in a sealable NMR tube provides an interesting result. The products observed by 1 H NMR spectroscopy are isobutylene (4.71 ppm, 2H; and 1.56 ppm, 6 H) and the new alkylidene complex [CF 3 ONO]W=CH(Et)OSiMe 3 ( 1 9 ) ( Figure 5 10) Complex 1 9 exhibits a new se t of diastereotopic C H 2 methylene protons at 5.28 and 4.91 ppm, and the trimethylsiloxide protons appear at 0.12 ppm. Corroborating the identity of 1 9 the W=C H proton resonates at 7.20 ppm and the corresponding 13 C{ 1 H} signal appears at 262.1 ppm. Multinuclear 1 H 13 C gHSQC and 1 H 13 C gHMBC NMR spectroscopic experiments confirm the identity of 1 9 and permit the absolute assignment of all resonances in the 1 H and 13 C{ 1 H} NMR spectra (A ppendix ). Complex 1 9 is unstable at ambient temperature and decomposes to unidentifiable and intractable impurities. 5.2.6 Catalytic I sobutylene E xpulsion from 16 As mentioned above, complex 16 contains a restricted amide rotation similar to that of complex 3 The amide lone pair and alkylidene of 16 form a torsion angle of 44.34. Considering th e reactivity of complex 1 7 would complex 16 undergo a similar reactivity in the presence of Me 3 SiOTf? Treating complex 16 with Me 3 SiOTf also results in isobutylene expulsion as well as the formation of [CF 3 ONO]W(O) n Pr ( 20 ). The absence of Me 3 SiOTf in the product suggests a catalytic role in the expulsion of isobutylene from 16 Indeed, adding 5 mol

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172 % Me 3 SiOTf, MeOTf, or B(C 6 F 5 ) 3 to a solution of 16 catalyzes isobutylene expulsion to form 20 quantitatively by 1 H NMR spectroscopy ( Figure 5 11 ). Stripping th e solvent from 20 initially yields a thick blue oil, but crystals suitable for single crystal X ray analysis gradually form (isolated yield = 73%). The solid state structure of 20 ( Figure 5 12 ) contains a tungsten(VI) ion in a trigonal bipyramidal geometry with equatorial plane angles N1 W1 O3 = 129.69, N1 W1 C21 = 121.46, and C21 W1 O3 = 108.82(10) . The W1 O3 bond is 1.704 , which is consistent with other reported neutral W VI =O complexes. 119, 384 402 The 19 F NMR of 20 confirms a C 1 symmetric species in solution with four quartets at 71.17, 71.77, 75.55, and 76.38 ppm. The protons of the propyl group {WC H 2 CH 2 CH 3 ) resonate in the 1 H NMR as a multiplet at 3.00 ppm. The protons and protons of the propyl group appear as a multiplet at 2.65 ppm and a triplet at 0.92 ppm, respectively. The nitrogen atom is sp 2 hybridized and a vector perpendicular to the amido plane, representing the lone pair on nitrogen, form s a 39.72 torsion angle with the W=O bond. 5.2.7 Computational Results Employing DFT calculations, the model complexes 16 16 Me' and 17 representing 16 the intermediate 16 Me and 1 7 respectively, w ere geometry optimized. Figure 5 13 depicts the co mputed structures and Table 5 1 and Table 5 2 list pertinent bond lengths and angles. Experimental bond lengths and angles for 16 serve to calibrate the calculated structure of 16 The tungsten coordination sphere metric parameters are agreeable and it is clear the calculation reproduces the twist of the ONO backbone observed experimentally. A vector perpendicular to the C3 W1 C13 plane, representing the nitrogen lone pair, creates a 41.7 dihedral angle with the W1 C1 bond axis (the experimental value is 40.5). Also, the alkylidene orients in the same direction

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173 as in 9 The alkylidene ethyl group points away from the N atom. A quantifiable parameter confirming the similar orientation is the dihedral angle C22 C21 W1 O3; for 16 it is 10.2 and within 9 it is 11.7. In general there is a small over estimate of most of the bond lengths by 0.02 or less. For example the N1 W1 distance of 2.013 in 16 is slightly longer than in 16 (1.993(3)); and the computed alkylidene W1 C21 bond length of 1.898 matches the experimental value of 1.882(4). The computed structures of 16 Me' and 1 7 also reproduce the ONO twist and some interesting trends emerge between the set of three complexes. Most apparent is the W N bond distance, that increases with 16 Me' (1.982) < 16 (2.013) < 1 7 (2.142). The computation accurately predicts a trend assignable to an increase in electronic saturation at the metal ion. Complex 1 7 is anionic, thus electron rich, whereas 16 Me' is electron donation upon me thylating the alkoxide O atom. Correspondingly, the W O bond length of 2.136 for the bound tert butylmethyl ether in 16 Me' is appropriately longer than the tert butoxide of 1 7 and only slight shorter by ~ 0.05 than the crystallographically character ized diethyl ether W O bond of 2.185(2) found in the related OCO 3 pincer alkylidyne [ t t Bu)(Et 2 O). 31 The most salient feature of complex 1 7 of 1.769 that matches experimentally deter mined values. Though there are no structurally characterized trianionic pincer alkylidyne anions known, two neutral OCO 3 1.755(2) and 1.759(4) . For additional 2 NpW C( t Bu) 403 complex contains a W C bond length of 1.755(2) , a difference of only ~0.01 with 10' Considering the reasonable match in

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174 metric parameters, single point calculations of e ach complex were performed and the resulting electronic structures were evaluated, vide infra. 5. 3 Discussion 5. 3 .1 An Enhanced Nucleophilic Reactivity from 1 7 MeOTf alkylation at the C atom of the alkylidyne in 1 7 has a different reactivity pattern compa red to previous examples. Alkylating agents preferentially attack the ancillary ligands leaving both neutral and anionic tungsten alkylidynes intact. 319 Similarly for anionic molybdenum imido alkylidyne compl exes, both small ([Me 3 O][BF 4 ]) and large (Me 3 SiOTf) electrophiles selectively attack the imido N atom. 339 The direct alkylation of the W C bond by MeOTf has no precedent in the literature. Enamines react with position, whereas unfuctionalized alkenes do not. Electronically, complex 1 7 is analogous to an enamine. Examining the electronic structure of 1 7 through sing le point calculations provides insight into how the CF 3 ONO pincer ligand influences the tungsten alkylidyne bond. 5.3.2 Single Point DFT Calculations of 1 7 Figure 5 14 depicts a truncated molecular orbital diagram that illustrates the bonding combination between the amido lone pair and the W bond. The key feature is the forced torsion angle between the alkylidyne bond and the amide lone pair. This contrasts the typical arrangement in which the nitrogen lone pair orients perpendicularly to the alkylidyne bond to donation into th e empty d xy The rigid ONO pincer geometry within 1 7 prevents the amide from orienting perpendicularly to the alkylidyne and instead the LUMO of 1 7 consisting of the d xy orbital, contains no orbital interaction with the amido lone pair ( Figure 5 14 ).

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175 Th bond facing the nitrogen (HOMO( 2)) displays overlap with the bond (HOMO( 1)) by 0.01139 AU ( Figure 5 14 ). A torsion angle of 42.8 between the lone pair and the alkylidyne bond results in significant overlap. The corresponding anti bonding combination corresponds to the HOMO orbital analogous to an enamine ( Figure 5 3 ). This bonding antibonding interaction raises the energy of the HOMO, thus increasing the nucleophilicity carbon. In stark contrast is the single point calculation from a geometry optimized structure performed on the model anionic alkylidyne {(Ph 2 3 ) 2 Ph) 2 (O t Bu)} ( 21 ). The amido ligand orientation matches the analogous compl ex {3,5 C 6 H 3 Me 2 ) t t Bu){OC(CF 3 ) 3 } 2 calculated by Tamm and co workers. 304 Depicted in Figure 5 15 are the s ingle point calculations of 1 7 and 21 aligned for easy comparison. The model complex 21 features an unrestricted amido ligand N(C 6 H 5 ) 2 yet retains the electron withdrawing OC(CF 3 ) 2 C 6 H 5 groups. In 21 the donation in to the empty d xy orbital, which serves to stabilize the HOMO orbital comprised mostly of the N atom lone pair. However, the M C bonding orbitals are completely unaffected by the N atom lone pair. By comparing the electronic structures, it is evident that purposely constraining the N atom lone pair to be carbon. 5.3.3 Isobutylene Expulsion from 10 Isobutylene expulsion provides more evidence for the nuc leophilicity of 1 7 Figure 5 16 illustrates a proposed mechanism for isobutylene expulsion. In the first step, Me 3 SiOTf attacks the tert butoxide ligand to yield the trimethylsilyl tert butyl ether

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176 adduct, 1 7 SiMe 3 Then, acting as a nucleophile, the W alk ylidyne deprotonates the tert butyl group to expel isobutylene and form 1 9 tert Butoxide is a common ligand, especially for tungsten complexes featuring M C multiple bonds, but this is the first occurrence of its degradation via alkylidyne deprotonation a nd is clear evidence of the highly nucleophilic character of the W C atom. Additional evidence that the N atom plays an important role comes from reactivity studies employing the related OCO 3 pincer ligand. Without the N atom a different reaction occurs ; addition of MeOTf to the analogous OCO trianionic pincer alkylidyne anion {MePPh 3 }{[ t t Bu)(O t Bu)} produces [ t t Bu)(OEt 2 ). 31 The reaction proceeds via Me alkylation of the tert butoxide but deprotonation does not occur; instead, MeO t Bu forms. Notably, the Me + adds to the alkoxide and not the carbon as in 1 7 Not all of the divergent chemistry between the CF 3 ONO 3 and the OCO 3 ligands are attributable to the N atom alone. An additional significant difference is the fluorinated alkoxides on CF 3 ONO 3 which create an electrophilic tungsten ion. Silylating the O t Bu of 1 7 donation from the alkoxide and leaves only a donating ether. The result is an even more electrophilic tungsten metal. Yet, other electrophilic tungsten alkylid ynes supported by three OC(CF 3 )Me are known metathesis catalysts that show stability towards substrates containing ether, ester, ketone, aldehyde, acetal, and thioether moieties, 281 and are only protonated via hydrohalic acids. 367, 404 The combination of the N atom and the electron withdrawing CF 3 groups must lead to deprotonation of the tert butoxide.

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177 5.3. 4 Isobutylene Expulsion from 16 The Lewis acid catalyzed expulsion of isobutylene from 16 demonstrates W C double bonds with the CF 3 ONO 3 ligands are also highly nucleophilic. Figure 5 17 depicts the proposed mechanism for the Lewis acid catalyzed isobutylene expulsion from 9 Two plausible sites for electrophilic ( LA ) attack on 16 are the amido N atom and the tert butoxide O atom. The N atom is too sterically crowded, especially for large electrophiles such as B(C 6 F 5 ) 3 and Me 3 SiOTf, which catalyze the reaction too. Thus, initial attack must occur at the tert butoxide to form 16 LA Proce eding from 16 LA, the alkylidene deprotonates the t Bu group to form isobutylene and 20 LA The Lewis acid catalyst is then released to provide 20 An interesting question arises regarding the deprotonation event. Structural characterization and subsequent variable temperature NMR experiments indicate the alkylidene W=C bond in 16 is perpendicular to the tert butoxide ligand ( Figure 5 18 ). To bond needs to approach the proton of the tert butoxide. Curious as to the orientation of the alkylidene in 16 LA we performed a geometry optimization calculation of 16 Me' in which Me + serves as the Lewis acid ( Figu re 5 13 ). The electrophile accepts a pair of electrons from the oxygen atom that donate into the W d xy orbital. Most pronounced and interestingly, the alkylidene in 16 Me' rotates ~77 from that of the experimentally determined structure of 16 Illustrated in Figure 5 18 is a truncated X ray structure of 16 and the computed structure 16 Me' The double bond clearly orients towards the MeO t Bu. A single point calculation of 16 Me' again reveals the HOMO and HOMO( 5) are the amide/alkylidene antib onding and bonding ( Figure 5 19) respectively, analogous to that calculated for

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178 1 7 and a prototypical enamine. The LUMO of 16 Me' (not depicted) consists of the d xy orbital and contains only a small component from N atom lone pair and ether ligand. 5.4 Conclusion Traditionally, tungsten alkylidenes/alkylidynes are weakly nucleophilic, and are ideally suited for alkene and alkyne metathesis. Presented above is a rationally designed ONO pincer type ligand that enhances the nucleophilicity of W C multiple b onds for C H activation. The [CF 3 ONO] ligand effective ly polarizes W C multiple bonds through a unique push pull combination The fluorinated alkoxides induce an electron deficient tungsten ion (pull) while the alignment of the amido lone pair with the W C multipl e bond carbon through a unique inorganic enamine interaction More importantly the inorganic enamine presents a new st r ategy to accentuate the nucleophilic ity of alkylidene and alkylidyne complexes. E vidence for the enhanc ed reactivity arising from an inorganic enamine is the direct alkylation of the alkylidyne in 10 with MeOTf; and isobutylene expulsion upon addition of the larger Me 3 SiOTf. Complementing these results is the Lewis acid catalyzed expulsion of isobutylene fr om 9 T rianionic pincer and pincer type ligands are suitable framework s to explore the reactivity from a constrain ed amide orientation Here we provide a new approach to increas e the nucleophilicity of M C multiple bonds that may be employed with other metal ligand multiple bonds. Future work in this area explores how the constrained amide orientation within a metal coordination sphere may induce/alter new types of reactivity

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179 5.5 Experimental 5.5.1 General Considerations Unless specified otherwise, all manipulations were performed under an inert atmosphere using standard Schlenk or glovebox techniques. Pentane, hexanes, toluene, diethyl ether (Et 2 O), dichloromethane, tetrahydrofuran (THF), and 1,2 dimethoxyethane (DME) were dried using a GlassContour dr ying column. Benzene d 6 (Cambridge Isotopes) was dried over sodium benzophenone ketyl, distilled or vacuum transferred, and stored over 4 molecular sieves. Bis(2 bromo 4 methylphenyl)amine, 307 PPh 3 CH 2 339 and ( t BuO) 3 286 were prepared according to published literature procedures. All other reagents were purchased from commercial vendors and used without further purification. 5.5.2 Analytical Techniques NMR Techniques: NMR spectra were obtained on Varian Gemini 300 MHz, Varian Mercury Broad Band 300 MHz, or Varian Mercury 300 MHz spectrometers. 1 H and 13 C{ 1 H} NMR spectra, the solvent peak was referenced as an internal reference. Elemental Analysis: Combustion analyses were performed at Complete Analysis Laborat ory Inc., Parsippany, New Jersey. IR Techniques: Infrared spectra were obtained on a Thermo Scientific Nicolet 6700 FT IR. 5. 5.3 Calculations Spin restricted density functional theory calculations, including geometry optimization and single point analys is were performed for 16 16 Me' 17 and 21 using a hybrid functional (the three parameter exchange functional of Becke (B3) 219 and the

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180 correlation functional of Lee, Yang, and Parr (LYP) 340 (B3LYP) a s implemented in the Gaussian 03 program suite. 218 The LANL2DZ basis set were used for all atoms within 16 16 Me' 17 and 21 341 The geometry was optimized using atomic coordinates from the crystal structure as an initial input and calculations for the vibrational frequencies were performed alongside the geometry optimization t o ensure the stability of the ground state as denoted by the absence of imaginary frequencies. Molecular orbital pictures were generated from Gabedit at their reported isovalues. 5.5. 5 Synthesis of [CF 3 ONO]W=CH(Et)(O t Bu) ( 16 ) A benzene solutions (2 mL) of 8 t Bu) 3 (315.9 mg, 0.711 mmol) were combined and stirred for 0.5 h. The solvent was evaporated and the residual solid was placed under vacuum for 4 h. Single crystals of 16 were grown from a pentane solution at 35 C (0.352 g, 60%). 1 H NMR (C 6 D 6 300 H ), 7.36 (t, 1H, 3 J = 7.64 Hz, WC H CH 2 CH 3 ), 6.81 (d, 1H, 3 J = 8.49 Hz, Ar H ), 6.66 (d, 1H, 3 J = 8.21 Hz, Ar H ), 6.60 (d, 1H, 3 J = 9.06 Hz, Ar H ), 6.59 (d, 1H, 3 J = 8.49 Hz, Ar H ), 5.08 (ddq, 1H, 2 J = 15.0 Hz, 3 J = 7.36 Hz, 3 J = 7.36 H )CH 3 ), 4.79 (ddq, 1H, 2 J = 15.0 Hz, 3 J = 7.36 Hz, 3 J = 7.36 Hz, WCHC( )(H)CH 3 ), 2.00 (s, 3H, C H 3 H 3 ), 1.21 (s, 9H, OC(C H 3 ) 3 and 0.77 (t, 3 J = 7.36 Hz, WCHCH 2 C H 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 71.2 (q, 3F, 4 J = 9.61 Hz), 71.5 (q, 3F, 4 J = 12.0 Hz), 73.9 (q, 3F, 4 J = 9.60 Hz), and 77.2 (q, 3F, 4 J = 9.61 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 W C HCH 2 CH 3 with satellites 1 J( 13 C, 183 W) = 173.1 Hz), 146 .8 (s, Ar C ), 145.8 (s, Ar C ), 135.1 (s, Ar C ), 134.6 (s, Ar C ), 133.0 (s, Ar C ), 131.7 (s, Ar C ), 127.5 (s, Ar C ), 124.7 (s, Ar C ), 124.5 (s, Ar C ), 124.3 (s, Ar C ), 90.3 (s, O C Me 3 ), 33.6 (s, WCH C H 2 CH 3 ), 29.8

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181 (s, OC( C H 3 ) 3 ), 21.4 (s, WCHCH 2 C H 3 ), 21.0 (s, A r C H 3 C H 3 ) ppm. Anal. Calcd. for C 27 H 27 F 12 NO 3 W (825.33 g/mol): C: 39.29%; H: 3.30%; N: 1.70%, Found; C: 39.25%; H: 3.37; N: 1.58%. 5.5. 6 Synthesis of {[CF 3 t Bu)}{MePPh 3 } (1 7 ) A pentane solution of CH 2 PPh 3 (131.5 mg, 0.476 mmol, 1.6 equiv) was filtered prior to drop wise addition to a stirring pentane solution of 16 (243.4 mg, 0.295 mmol, 1 equiv). Red oil formed upon complete addition and the re action mixture was triturated in the pentane solution for 6 h to yield a yellow powder. The powder was filtered, washed with pentane, and dried overnight (0.170 g, 83%). 1 H NMR (C 6 D 6 7.81 (s, 1H, Ar H ), 7.66 (s, 1H, Ar H ), 7.51 (d, 1H Ar H 3 J = 8.35 Hz), 7.20 (d, 1H, Ar H 3 J = 8.95 Hz), 7.01 (b, (C 6 H 5 ) 3 PCH 3 ), 6.98 (b, (C 6 H 5 ) 3 PCH 3 ) 6.92 (dd, 1H, Ar H 3 J = 8.65 Hz, 4 J = 1.64 Hz), 6.80 (dd, 1H, Ar H 3 J = 8.35 Hz, 4 J = 1.64 Hz), 4.35 (q, 2H, WCC H 2 CH 3 3 J = 7.61 Hz), 2.44 (d, 3H, (C 6 H 5 ) 3 PC H 3 2 J =13.31 Hz), 2.16 (s, 3H, Ar C H 3 ), 2.09 (s, 3H, Ar C H 3 H 3 ) 3 ), and 0.80 (t, 3H, WCCH 2 C H 3 3 J = 7.64 Hz) ppm. 31 P{ 1 H} NMR (C 6 D 6 19 F{ 1 H} NMR (C 6 D 6 300 MHz, 25 C): 69.38 (q, 3F, 4 J = 8.30 Hz), 71.24 (q, 3F, 4 J = 10.38 Hz), 74.08 (q, 3F, 4 J = 10.38 Hz), and 76.38 (q, 3F, 4 J = 8.30 Hz) ppm. Anal. Calcd. for C 46 H 44 F 12 NO 3 PW (1096.64 g/mol): C: 50.15%; H: 4.03%; N: 1.27%, Found; C: 50.15%; H: 3.96; N: 1.32%. 5.5. 7 Preparation of [CF 3 ONO]W=C(CH 3 )(Et)(O t Bu) (1 8 ) To a benzene (1 mL) solution of 1 7 (0.024 g, 2.1 x10 5 mol) was added MeOTf (0.004 mg, 2.1 x10 5 mol). The reaction solution turned immediately from red to brown and the solvent was removed in vacuo. The residue was dissolved in Et 2 O and filtered

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182 to remove a colorless precipitate (MePPh 3 OTf). The solvent was removed again in vacuo and the residue was dissolved in pentane and filtered. Removal off all volatiles from the filtrate provides 1 8 along with intractable impurities (<10%) thus precluding combustion analysis. Multinuclear and 2D NMR techniques provide the unambiguous characterization of 1 8 and the absolute assignment of all 1 H and 13 { 1 H} NM R resonances. 1 H NMR (C 6 D 6 H ), 7.65 (s, 1H, Ar H ), 6.76 (d, 1H, 3 J = 8.50 Hz, Ar H ), 6.71 (d, 1H, 3 J = 8.50 Hz, Ar H ), 6.61 (d, 1H, 3 J = 8.80 Hz, Ar H ), 6.51 (d, 1H, 3 J = 8.80 Hz, Ar H ), 4.87 (s, 3H, WC(C H 3 )CH 2 CH 3 ), 4.62 (m, 1H, WCHC( )(H)CH 3 ), 4.50 (m, 1H, WCHC(H )( H )CH 3 ), 1.93 (s, 6H, C H 3 ), 1.19 (s, 9H, OC(C H 3 ) 3 and 0.70 (t, 3 J = 7.33 Hz, WCHCH 2 C H 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 500 76.3 (q, 3F, 4 J = 8.48 Hz), 75.6 (q, 3F, 4 J = 9.69 Hz), 71.1 (q, 3F, 4 J = 9.69 Hz), and 70.8 (q, 3F, 4 J = 8.48 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 500 MHz, 25 C): C (CH 3 )CH 2 CH 3 ), 145.3 (s, Ar C ), 142.8 (s, Ar C ), 134.2 (s, Ar C ), 133.2 (s, Ar C ), 131.9 (s, Ar C ), 131.6 (s, Ar C ), 127.3 (s, Ar C ), 126.9 (s, Ar C ), 126.5 (s, Ar C ), 124.0 (s, Ar C ), 122.8 (s, Ar C ), 89.9 (s, O C (CH 3 )), 34.0 (s, WC(CH 3 ) C H 2 CH 3 ), 29.1 (s, OC( C H 3 ) 3 ), 23.5 (s, WC( C H 3 )CH 2 CH 3 ), 20.4 (s, Ar C H 3 C H 3 ), and 18.4 (s, WC(CH 3 )CH 2 C H 3 ) ppm. 5.5. 8 Preparation of [CF 3 ONO]W=CH(Et)(OSiMe 3 ) ( 1 9 ) To a diethyl ether (1 m L) solution of 1 7 (0.143 g, 1.30 x10 4 mol) was added Me 3 SiOTf (0.029 mg, 1.31 x10 4 mol). The reaction solution turned immediately from red to brown and a colorless precipitate formed (MePPh 3 OTf). The solid was removed by filtration and the filtrate was r educed to provide a brown oil. The product was immediately re dissolved in C 6 D 6 to prevent decomposition. The product was found to

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183 decompose when left as an oil for several hours, thus precluding combustion analysis. However, the complex was stable long en ough in solution to be characterized by multinuclear and 2D NMR techniques, thus providing its unambiguous assignment. 1 H NMR (C 6 D 6 H ), 7.66 (s, 1H, Ar H ), 7.20 (t, 1H, W=C H CH 2 CH 3 3 J = 7.04 Hz), 6.71 (d, 1H, Ar H 3 J = 8.21 Hz), 6.61 (d, 1H, Ar H 3 J = 8.21 Hz), 6.53 (d, 1H, Ar H 3 J = 8.21 Hz), 6.51 (d, 1H, Ar H 3 J = 8.21 Hz), 5.28 (m, 1H, WCHC(H H )CH 3 ), 4.91 (m, 1H, WCHC( H 3 ), 1.97 (s, 3H, Ar C H 3 ), 1.93 (s, 3H, Ar C H 3 2 C H 3 3 J = 7.33 Hz), and 0.12 (s, 9H, OSi(C H 3 ) 3 ) ppm. 19 F{ 1 H} NMR (C 6 D 6 500 MHz, 25 C): 69.38 (q, 3F, 4 J = 9.61 Hz), 71.24 (q, 3F, 4 J = 9.61 Hz), 74.08 (q, 3F, 4 J = 9.61 Hz), and 76.38 (q, 3F, 4 J = 9.61 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 C HCH 2 CH 3 ), 145.8 (s, Ar C ), 145.0 (s, Ar C ), 134.5 (s, Ar C ), 134.0 (s, Ar C ), 132.0 (s, Ar C ), 131.0 (s, Ar C ), 127.2 (s, Ar C ), 126.9 (s, Ar C ), 126.4 (s, Ar C ), 123.7 (s, Ar C ), 123.6 (s, Ar C ), 123.1 (s, Ar C ), 31.3 (s, WCH C H 2 CH 3 ), 20.6 (s, WCHCH 2 C H 3 ), 20.2 (s, Ar C H 3 C H 3 ), and 0.1 (s, OSi( C H 3 ) 3 ) ppm. 5.5. 9 Synthesis of [CF 3 ONO]W(O)( n Pr) ( 20 ) To a 2.0 mL benzene solution of 16 (398 mg, 4.82 x10 4 mol) was added trimethylsilyl triflate (1 mg, 4.5 x10 6 mol ) in benzene (1 mL). The solution changed from reddish brown to aquamarine blue over the period of 2 h. The solution was evaporated in vacuo to remove solvent and trimethylsilyl triflate providing an oil. Crystals of 20 formed from the oil after 3 h. The c rystals were removed by spatula (0.274 g, 74.6%). 1 H NMR (C 6 D 6 H ), 6.73 (d, 1H, Ar H 3 J = 8.21 Hz), 6.68 (d, 1H, Ar H 3 J = 8.80 Hz), 6.61 (d, 1H, Ar H 3 J = 8.21 Hz), 6.52 (d, 1H, Ar H 3 J =

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184 8.80 Hz), 3.03 2.97 (m, 2 H, WC H 2 CH 2 CH 3 ), 2.81 2.52 (m, 2H, WCH 2 C H 2 CH 3 ), 1.92 (s, 3H, Ar C H 3 ), 1.88 (s, 3H, Ar C H 3 ), and 0.92 (t, 3H, WCH 2 CH 2 C H 3 3 J = 7.33 Hz) ppm. 19 F{ 1 H} NMR (C 6 D 6 300 MHz, 25 C): 71.17 (q, 3F, 4 J = 8.48 Hz), 71.77 (q, 3F, 4 J = 9.69 Hz), 75.55 (q, 3F, 4 J = 9 .69 Hz), and 76.38 (q, 3F, 4 J = 8.48 Hz) ppm. 13 C{ 1 H} NMR (C 6 D 6 132.8 (s, Ar H), 127.5 (s, Ar H), 125.4 (s, Ar), 123.0 (s, Ar H) 82.7 (s, W C H 2 CH 2 CH 3 with satellites 1 J( 13 C, 183 W) = 109.1 Hz), 26.9 (s, WCH 2 C H 2 CH 3 ), 21.0 (Ar C H 3 ), 20.7 (s, WCHCH 2 C H 3 ), and 19.3 (s, Ar C H 3 24 H 22 F 12 NO 3 W (769.22 g/mol): C: 36.76%; H: 2.83%; N: 1.79%, Found; C: 36.67%; H: 2.87; N: 1.79%.

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185 Figure 5 1 A mido p orbital aligned wi th d xy and amido p orbital rotated out of alignment. Figure 5 2 Two possible resonance co ntributions for an enamine and amidoalkylidene Figure 5 3 Truncated qualitative orbital diagram of the bonding analogy between enamines 374 and amidoalkylidenes.

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186 Figure 5 4 Push pull synergetic effect of the [CF 3 ONO] 3 pincer type ligand. Figure 5 5 Synthesis of 16 Figure 5 6 Molecular structure of [CF 3 ONO]W=CH(Et)(O t Bu) ( 16 ) with ellipsoids drawn at the 50% probability level, and hydrogen atoms removed for clarity.

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187 Figure 5 7 Synthesis of 1 7 Figure 5 8 Methylation of 17 to form 1 8 Figure 5 9 Isobutylene e xpulsion from 1 7 to form 1 9

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188 Figure 5 10 Lewis a cid c atalyzed i sobutylene e xpulsion from 16 to form 20 Figure 5 11 Molecular structure of [CF 3 ONO]W(O) n Pr ( 20 ) with ellipsoids drawn at the 50% probability level, a nd hydrogen atoms removed for clarity.

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189 Figure 5 12 Geometry optimized structures for 16 ', 16 Me ', and 1 7 '. Table 5 1 Selected bond lengths () for the single crystal X ray structure of 9 and DFT geometry optimized structures of 16 16 Me' and 1 7 Bond Lengths 16 16 16 Me 17 W1 O1 1.953(2) 1.982 1.884 2.001 W1 O2 1.931(2) 1.953 1.880 1.991 W1 O3 1.819(2) 1.836 2.136 1.917 W1 N1 1.993(3) 2.013 1.982 2.142 W1 C21 1.882(4) 1.898 1 .986 1.769 C21 C22 1.499(5) 1.519 1.507 1.493 O3 C28 1.498

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190 Table 5 2 Selected bond angles () for the single crystal X ray structure of 9 and DFT geometry optimized structures of 16' 16 Me' and 17' Angles 16 16 16 Me 17 O1 W1 O2 144.95(11) 145.68 156.17 146.18 O1 W1 C21 104.44(13) 103.65 99.44 103.39 N1 W1 O3 154.64(11) 155.42 151.23 153.28 N1 W1 C21 99.81(14) 97.98 101.36 98.06 O2 W1 C21 109.41(13) 108.38 104.08 106.26 O3 W1 C21 105.50(13) 106.48 107.4 0 108.65 C22 C21 W1 137.2(3) 137.44 134.18 176.20 C28 O3 W1 111.50 Figure 5 13 The HOMO, HOMO( 1), and HOMO( 2) orbitals of 1 7 (Isovalue = 0.051687).

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191 Figure 5 14 The HOMO, HOMO( 1), and HOMO( 2) orbitals of 1 7 ; and t he HOMO, HOMO( 1), and HOMO( 2) orbitals of 21 (Isovalue = 0.051687).

PAGE 192

192 Figure 5 15 Proposed mechanism for isobutylene expulsion from 1 7

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193 Figure 5 16 Proposed m echanism for i sobutylene e xpulsion from 16 (LA = Me + Me 3 Si + and B(C 6 F 5 ) 3 Figure 5 17 T runcated X ray structure of 16 and geometry optimized structure 16 Me' illustrating the 77 rotation of the W=C bond.

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194 Figure 5 18 The HOMO, HOMO( 1), and HOMO( 5) orbitals of 16 Me' (Isovalu e = 0.051687).

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195 CHAPTER 6 FUTURE W ORK TOWARDS AN ACTIV E ALKYNE METATHESIS CATALYST FEATURING A NEW TRIA NIONIC ONO PINCER TYPE LIGAND. 6 .1 Introduction C hapter s 4 and 5 introduce the trianionic [CF 3 ONO ] pincer type ligand supported tungsten alkylidyne. Th e [CF 3 ONO] ligand with its unique push pull electronic combination serves a unique role in polarizing W C multiple bonds. This electronic environment coupled with the poor steric groups on the pendant arm render s the tun gsten alkylidyne complex as an u nsu itable catalyst for alkyne metathesis (Chapter 4 ), but promotes an unusual C H bond activation from a tungsten alkylidyne and alkylidene (Chapter 5 ). M ore recent work centers on the creation of a new trianionic ONO pincer type ligand for alkyne metathesis. Our goal is to destabilize the metallacyclobutadiene by increasing the per ipheral steric bulk and avoiding an y inorganic enamine interaction Figure 6 1 depicts the proposed ONO ligand to support an alkyne metathesis catalyst. A notable feature is the bulky t Bu on the pendant arms that should provide steric pressure on the WC 3 r ing of the tungstena cyclo butadiene intermediate. Additionally, the central N donor moiety is a pyrrole. The nitroge n lone pair which previously le d to the inorganic enamine interaction, should be consumed within the pyrroles aromatic ity 6.2 Results and Discussion 6 .2.1 Progess towards the S ynthesis of [ pyr ONO]H 3 Our initial approach to preparing the [pyr ONO] ligand is depicted in Figure 6 2 (red arrows) Combining a CH 2 C l 2 solution of succinyl dic hloride with a 10% NaOH solution of the selected phenol yields the the diester product as intended. 405 However, the second steps involving a Fri edel Craft rearrangement produces the respective 1,4

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196 bis(2 hydroxyphenyl)butane 1,4 dione 406, 407 but also removes the ortho R groups ( Figure 6 2 ). Replacing the R substi tuent in the ortho substituent upon subjecting 1,4 bis(2 hydroxyphenyl)butane 1,4 dione to a Friedel Craft alkylation with 2 chloro 2 methylpropane was unsuccessful Additionally, using TiCl 4 instead of AlCl 3 does not induce any rearrangement. As such, wit hout the sterically R groups attached, a new synthetic route was explored. The second approach to synthesize the [py ONO] ligand involves a S uzuki coupling of dibromopyrrole with (3 (tert butyl) 2 methoxyphenyl)boronic acid ( Figure 6 3) The reaction proc eeds at 95 C over 18 h. Resulting workup in acidic media removes the BOC protecting group. C ompound 22 is purified by crystallization from a concentrated 2 propanol solution. In the 1 H NMR spectrum of 22 the pyrrole NH proton appears as a broaden signal at 9.90 ppm, and the corresponding pyrrole aromatic proton resonates as a doublet ( 4 J = 2.68 Hz) at 6.55 ppm. In the alkyl region, the methoxy and the tert butyl protons resonate at 3.57 and 1.46 ppm, respectively. The methyl protecting groups of 22 are easily removed with excess BBr 3 in CH 2 Cl 2 at 0 C. T he 1 H NMR spectrum of the crude reaction mixture confirms the removal of the methyl group. However, the resulting product is not the protio ligand. The proton signals attributable to the NH and OH are no t present in the 1 H NMR spectrum. Rather a boron atom inserted inside the tridentate ligand. Mass spectroscopy confirms a single boron atom and the identity of complex 23 The 1 H NMR spectrum of 23 contains the pyrrole C H protons a s a singlet at 6.71 and the tert butyl groups now resonate at 1.52 ppm.

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197 Attempts to remove the boron atom from 23 with HCl or KO t Bu were unsucessful. Using the strong base n BuLi appear s to remove the boron atom, however, the protio ligand was not able to be separated from intractable impurities. F uture work involves exploring new methyl deprotecti ng agents with complex 22 One example that we are currently looking into is 2 (dimethylamino)ethanethiol 6.3 Experimental 6 3 .1 General Considerations Unless specified otherwi se, all manipulations were performed under an inert atmosphere using standard Schlenk or glovebox techniques. Pentane, hexanes, toluene, diethyl ether (Et 2 O), dichloromethane, tetrahydrofuran (THF), and 1,2 dimethoxyethane (DME) were dried using a GlassCon tour drying column. Benzene d 6 (Cambridge Isotopes) was dried over sodium benzophenone ketyl, distilled or vacuum transferred, and stored over 4 molecular sieves. tert Butyl 2,5 dibromo 1H pyrrole 1 carboxylate 408 and (3 ( tert butyl) 2 methoxyphenyl)boronic acid 409 were prepared according to published literature procedures. All other reagents were purchased from commercial vendors and used without further purification. 6 3 2 Analytical Techniques NMR Techniques: NMR spectra were obtained on Varian Gemini 300 MHz, Varian Mercury Broad Band 300 MHz, or Varian Mercury 300 MHz spectrometers. 1 H and 13 C{ 1 H} NMR spectra, the solvent peak was referenced as an internal reference. 6.3.3 Synthesis of 2,5 bis(3 ( tert butyl) 2 methoxyphenyl) 1H pyrrole Inside an argon filled glove box, a toluene solution (15 mL) containing (3 (tert butyl) 2 methoxyphenyl)boronic acid (0.660 g, 3.17 x10 3 mol, 2.3 equiv.),

PAGE 198

198 tetrakis(triphenylphosphine) palladium(0) (0.159 g, 1.38 x10 4 mol, 0.10 equiv.), Na 2 CO 3 (1.16 g, 1.09 x10 2 7.9 equiv.), KCl (0.308 g, 4.13 x10 3 mol, 3 equiv.), and tert butyl 2,5 dibromo 1H pyrrole 1 carboxylate (0.448 g, 1.38 x10 3 m ol, 1 equiv.) were prepared. The reaction flask was fitted with a Liebig condenser and y adapter prior to exiting the glovebox and attached to the argon Schlenk line. Under counter argon pressure, 15 mL of degassed ethanol water (2:1) solution was added to the reaction flask. The reaction mixture was heated at 96 C with stirring for 20 h, during that time the solution changes from yellow to orange red color. The reaction mixture was allowed to cool, and then solvent was removed under reduced pressure. The residue was dissolved in CH 2 Cl 2 (15 mL) and washed with water and brine. The organic layer was dried with MgSO 4 and the solvent was removed under reduced pressure. To the residue, 20 mL of hexanes was added to precipitate a white solid. The mixture was st irred for 0.5 h before filtering off the white solid. The collected filtrate was reduced under vacuum to yield an orange oil containing the BOC protected pyrrole. The Boc protecting group is easily removed upon stirring the residue with 10 mL of 4 M HCl in 1,4 dioxane at 45 C for 18 h. The solvent was removed under reduced pressure. The residue was dissolved in DCM, washed with saturated solution of Na 2 CO 3 and then water. The organic layer was dried with MgSO 4 prior to removing the solvent under reduced pr essure. The purple oily residue was dissolved in minimal 2 propanol (5 mL). Cooling the 2 propanol solution precipitates crystals of the product, 2,5 bis(3 ( tert butyl) 2 methoxyphenyl) 1H pyrrole (Yield = 0.219, 47%). 1 H NMR (CDCl 3 H ), 7.42 (dd, 2H, 3 J = 7.57 Hz, 4 J = 1.71 Hz, Ar H ), 7.24 (dd, 2H, 3 J = 7.93 Hz, 4 J = 1.71 Hz, Ar H ), 7.07 (t, 2H, 3 J = 7.81 Hz, Ar H ), 6.55 (d, 2H, 4 J = 2.68 Hz, Ar H ), 3.57 (s, 6 H, OC H 3 ), 1.46 (s, 18 H,

PAGE 199

199 C(C H 3 ) 3 ) pp m. 13 C{ 1 H} NMR (CDCl 3 C ), 143.4 (s, Ar C ), 130.0 (s, Ar C ), 127.4 (s, Ar C ), 126.9 (s, pyr C ), 125.5 (s, Ar C ), 123.8 (s, Ar C ), 108.1 (s, pyr C ), 60.8 (s, O C H 3 ), 35.2 (s, C (CH 3 ) 3 ), 31.0 (s, C( C H 3 ) 3 ) ppm. ESI MS: 371 21 [1 + H] +

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200 Figure 6 1 Proposed alkyne metathesis catalyst featuring a trianionic [pyr ONO] pincer type ligand. Figure 6 2 Proposed synthesis of [pyr ONO] pincer type ligand (red arrows) and actual outcome

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201 Figure 6 3 Proposed synthesis of [pyr ONO] pincer type ligand (red arrows) and actual outcome.

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202 AP PENDIX A SUPPORTING INFORMATI ON A.1 NMR Data Figure A 1 1 H NMR Spectra of 1 obtained in THF d 8 Figure A 2 13 C{ 1 H} NMR Spectra of 1 obtained in THF d 8

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203 Figure A 3 1 H NMR spectrum of 2 in C 6 D 6

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204 Figure A 4 1 H NMR spectrum of 3 in C 6 D 6

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205 Figure A 5 1 H NMR spect rum of 4 in C 6 D 6

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206 Figure A 6 1 H NMR of 5 in C 6 D 6 Figure A 7 1 H NMR of 5 dissolved in THF d 8 to form 2 ( characteristic peaks = 8.20, 7.44, 13.23 ppm) and 3

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207 Figure A 8 1 H NMR of 6 in C 6 D 6 with 0.01 mL THF d 8 Figure A 9 1 H NMR of 5 (2.43 x10 5 mol) in C 6 D 6 (red) and with OPPh 3 (5.82 x10 5 ) in C 6 D 6 (blue).

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208 Figure A 10 Labelling scheme for 1 H and 13 C NMR peaks.

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209 Table A 1 1 H, 13 C, 19 F and 15 N chemical shifts in compounds 8 15 Compd. 8 15 16 17 18 19 20 a 21 C1 80.6 82.8 83.6 86.2 86.2 80.8 81.2 80.8 C2 120.9 123.5 121.0 135.5 135.3 124.9 124.8 125.0 C3 143.0 146.5 154.5 152.4 151. 0 146.0 145.7 144.6 C4 126.1 123.9 122.9 nm nm 127.7 126.5 125.8 C5 132.1 131.0 130.3 130.6 131.0 131.9 132.1 132.0 C6 134.4 133.6 122.6 130.8 132.5 131.9 131.8 131.4 C7 128.3 126.2 127.0 127.5 127.5 126.9 127.1 126.9 C8 123.2 124.6 nm nm nm nm 123.9 123.3 C9 123.3 123.7 nm 124.8 124.5 nm 123.5 123.9 C10 20.2 20.1 20.5 20.7 20.6 20.3 20.3 20.3 C11 80.6 84.3 85.4 85.4 84.9 81.6 = C1 81.8 C12 120.9 127.5 131.5 118.0 119.3 124.5 = C2 124.2 C13 143.0 145.4 155.5 151.4 150.5 144.9 = C3 145.1 C14 126 .1 123.9 126.2 121.1 122.3 127.1 = C4 126.0 C15 132.1 133.0 130.2 130.8 131.3 132.4 = C5 132.4 C16 134.4 134.4 127.8 126.2 128.7 132.4 = C6 131.9 C17 128.3 127.3 127.2 127.1 126.8 127.3 = C7 127.3 C18 123.2 124.3 nm 124.5 124.3 nm =C8 123.5 C19 123.3 123.7 nm 124.7 123.7 nm = C9 123.5 C20 20.2 20.3 20.7 20.3 20.2 20.4 = C10 20.4 C21 262.6 286.0 308.6 311.5 242.3 252.0 238.6 C22 41.0 49.4 49.5 49.9 138.2 138.2 142.8 C23 35.0 33.7 33.7 33.6 244.6 = C21 252.8 C24 90.4 77.1 120.1 79.3 42.3 43 .5 42.0 C25 29.2 33.5 nm 13.4 30.2 30.1 31.0 C26 8.5 8.3 15.8 11.6 26.9 C27 118.7 118.6 138.2 = C24 31.0 C28 132.5 132.6 129.9 = C25 24.0 C29 129.9 130.0 128.3 26.0 C30 134.6 134.7 129.2 29.5 C31 35.5 N 66 .2 225.7 149.3 165.5 178.3 208.6 204.4 202.1 H4 6.69 6.54 7.05 7.27 7.05 7.00 7.02 7.07 H5 6.63 6.33 6.72 6.85 6.80 6.67 6.80 6.80 H7 7.47 7.68 7.59 7.77 7.73 7.58 7.57 7.65 H10 1.83 1.97 2.03 2.06 2.01 1.95 1.96 2.00 H14 6.69 6.54 7.44 6.91 6.70 7.05 = H4 7.06 H15 6.63 6.78 6.90 6.74 6.70 6.84 = H5 6.83 H17 7.47 7.67 7.73 7.62 7.65 7.60 = H7 7.57

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210 Table A 1 Continued Compd. 8 15 16 17 18 19 20a 21 H20 1.83 1.91 2.12 2.02 2.00 1.98 = H10 1.96 H21 6.42 H23 1.12 1.15 1.02 0.80 H24 3.58, 3.78 H25 1.21 1.64 0.84 1.15 1.15 1.13 H26 2.33 2.27 2.78 2.93 3.76, 3.30 H27 1.30, 1.30 H28 6.99 7.10 7.02 = H25 1.13, 0.90 H29 6.99 7.15 7.09 1.15, 0.90 H30 7.07 7.23 6.86 1.45, 1.3 5 H31 3.12, 3.61 F8 e 74.16 71.11 68.95 68.50 68.74 71.57 71.39 75.72 F9 75.69 73.03 72.15 76.19 76.71 75.55 76.05 71.89 F18 74.16 70.29 66.43 72.75 71.30 70.99 = F8 76.23 F19 75.69 76.90 73.95 73.38 74.94 76. 02 = F9 70.59 F24 76.22 F25 77.68 The fluorine signals in compounds 15 21 are quartets with a typical coupling constant of 9 signals too weak to measure. a Complex 20 is C 2 symmetric resulting in equi valent positions. Compounds 8 15 were characterized by 1 H, 13 C, 19 F and 15 N NMR. The chemical shifts are presented in Table A 1. The assignments were made primarily based on the cross peaks seen in the 1 H 13 C gHMBC spectra. The chemical shifts of the flu orinated carbons were measured in the 19 F 13 C gHSQC spectra, and their assignment to positions 8 and 9 vs. 18 and 19 was made based on the long range coupling of the fluorines to the quaternary carbon two bonds away, coupling seen in the 19 F 13 C gHMBC spec tra. The chemical shift of the 15 N was measured in the 1 H 15 N gHMBC spectrum, where it shows cross peaks with H4 and H14. No stereochemical assignments were made, i.e. H7 and H17 are interchangeable, as well as C8 and C9. In Table A 1, C1 and C2 were assi gned as the most shielded of the pairs C1, C11 and C2, C12; F8 and F9 were assigned as the most deshielded of the pairs F8, F18 and F9, F19.

PAGE 211

211 In a typical assignment procedure, H7 displays cross peaks with a carbon around 20 ppm, assigned as C10, with a car bon around 80 85 ppm, assigned as C1, with a carbon around 150 160 ppm, assigned as C3 and with a carbon around 130 ppm, assigned as C5. H10, H5 and C7 were then identified by one bond correlations, or by the couplings H10 C5, H10 C7, H5 C7. H4 was identif ied as coupling with H5, or by its coupling with C6, the third carbon coupling with H10. One coupling of F8 or F9 with C1 was sufficient to identify these fluorines, since the pairs H8 F9 and F18 F19 are revealed by selective decoupling in the 19 F spectra. The assignments for the positions 11 20 was done in a similar way to the one for positions 1 10. The proton signals for positions 21 27 can be assigned based on their intensity and multiplicity. The carbons in these positions were assigned based on their one bond and long range couplings to protons. The 13 C chemical shifts difference in positions 3/13and 6/16 as well as the 15 N chemical shifts difference between compounds 16 17 and 18 on one hand and 15 19 20 and 21 on the other suggest that in 16 17 and 18 while in 15 19 20 and 21

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212 Figure A 11 1 H NMR (CDCl 3, 300 MHz) spectrum of 8 Figure A 12 Variable Temperature 19 F{ 1 H} NMR (CDCl 3, 300 MHz) spectrum of 8 at 25 C (blue), 35 C (green), 45 C (gray), and 55 C (red)

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213 Figure A 13 13 C{ 1 H} NMR (CDCl 3, 300 MHz) spectrum of 8 Figure A 14 13 C{ 19 F} NMR (CDCl 3, 300 MHz) spectrum of 8

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214 Figure A 15 1 H 13 C gHMBC (C 6 D 6, 500 MHz) spectrum of 8 Figure A 16 1 H 13 C gHMBC (C 6 D 6, 500 MHz) spectrum of 8 expanded.

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215 Figure A 17 1 H 15 N gHMBC (C 6 D 6, 500 MHz) spectrum of 8 Figure A 18 19 F 13 C gHSQC (C 6 D 6, 500 MHz) spectrum of 8

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216 Figure A 19 1 H NMR spectrum of 9 in C 6 D 6 Figure A 20 19 F{ 1 H} NMR spectrum of 9 in C 6 D 6

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217 Figure A 21 1 H{ 13 C} gHSQC NMR spectrum of 9 in C 6 D 6 Figure A 22 1 H{ 13 C} gHMBC NMR spectrum of 9 in C 6 D 6

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218 Figure A 23 1 H{ 15 N} gHMBC NMR spectrum of 9 in C 6 D 6 Figure A 24 19 F{ 1 H} NMR spectra of 9 in C 6 D 6 (bottom) and with selective decoupling (top).

PAGE 219

219 Figure A 25 19 F{ 13 C} gHMBC NMR spectru m of 9 in C 6 D 6 expanded. Figure A 26 19 F{ 13 C} gHSQC NMR spectrum of 9 in C 6 D 6 expanded.

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220 Figure A 27 19 F{ 13 C} gHSQC NMR spectrum of 9 in C 6 D 6 expanded. Figure A 28 1 H NMR spectrum of 1 0 in C 6 D 6

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221 Figure A 29 19 F{ 1 H} NMR spectrum of 1 0 in C 6 D 6 Figure A 30 31 P{ 1 H } NMR spectrum of 1 0 in C 6 D 6

PAGE 222

222 Figure A 31 1 H{ 13 C} gHSQC NMR spectrum of 1 0 in C 6 D 6 Figure A 32 1 H{ 13 C} gHMBC NMR spectrum of 1 0 in C 6 D 6 The signals at 278.5 and 16.0 in f1 are 8.5 and 286. 0, foled.

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223 Figure A 33 1 H{ 15 N} gHMBC NMR spectrum of 10 in C 6 D 6 Figure A 34 19 F{ 1 H} NMR spectra of 10 in C 6 D 6 (bottom) and with selective decoupling (top).

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224 Figure A 35 19 F{ 13 C} gHMBC NMR spectrum of 1 0 in C 6 D 6 expanded. Figure A 36 1 H NMR spectrum of 1 1 in C 6 D 6

PAGE 225

225 Figure A 37 19 F{ 1 H} NMR spectrum of 11 in C 6 D 6 Figure A 38 31 P{ 1 H} NMR spectrum of 11 in C 6 D 6

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226 Figure A 39 1 H{ 13 C} gHMBC NMR spectrum of 1 1 in C 6 D 6 Figure A 40 1 H{ 13 C} gHMBC NMR spec trum of 1 1 in C 6 D 6 expanded.

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227 Figure A 41 1 H{ 13 C} gHMBC NMR spectrum of 1 1 in C 6 D 6 expanded. Figure A 42 1 H{ 13 C} gHMBC NMR spectrum of 1 1 in C 6 D 6 expanded.

PAGE 228

228 Figure A 43 1 H{ 15 N} gHMBC NMR spectrum of 1 1 in C 6 D 6 expanded. Figure A 44 19 F{ 13 C} gHMBC NMR spectrum of 1 1 in C 6 D 6 expanded.

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229 Figure A 45 19 F{ 13 C} gHSQC NMR spectrum of 1 1 in C 6 D 6 Figure A 46 1 H NMR spectrum of 1 2 in C 6 D 6

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230 Figure A 47 19 F{ 1 H} NMR spectrum of 1 2 in C 6 D 6 Figure A 48 1 H{ 13 C} gHMBC NMR spectrum of 1 2 in C 6 D 6

PAGE 231

231 Figure A 49 1 H{ 13 C} gHMBC NMR spectrum of 1 2 in C 6 D 6 expanded. Figure A 50 1 H{ 13 C} gHMBC NMR spectrum of 1 2 in C 6 D 6 expanded.

PAGE 232

232 Figure A 51 1 H{ 13 C} gHMBC NMR spectrum of 1 2 in C 6 D 6 expanded. Figure A 52 1 H{ 13 C} gHMBC NMR spectrum of 1 2 in C 6 D 6 expanded.

PAGE 233

233 Figure A 53 1 H{ 15 N} gHMBC NMR spectrum of 1 2 in C 6 D 6 expanded. Figure A 54 19 F{ 1 H} NMR spectra of 12 in C 6 D 6 (bottom) and with selective decoupling (top).

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234 Figure A 55 19 F{ 13 C} gHMBC NMR spectrum of 1 2 in C 6 D 6 Figure A 56 19 F{ 13 C} gHSQC NMR spectrum of 1 2 in C 6 D 6

PAGE 235

235 Figure A 57 1 H NMR spectrum of 1 3 in C 6 D 6 Figure A 58 19 F{ 1 H} NMR spectrum o f 1 3 in C 6 D 6

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236 Figure A 59 13 C{ 1 H} NMR spectrum of 1 3 in C 6 D 6 Figure A 60 1 H{ 13 C} gHMBC NMR spectrum of 1 3 in C 6 D 6

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237 Figure A 61 1 H{ 15 N} gHMBC NMR spectrum of 1 3 in C 6 D 6 Figure A 62 19 F{ 1 H} NMR spectra of 13 in C 6 D 6 (bottom) and with selective decoupling (top).

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238 Figure A 63 1 H NMR spectrum o f 14 in C 6 D 6 Figure A 64 19 F{ 1 H} NMR spectrum of 14 in C 6 D 6

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239 Figure A 65 13 C{ 1 H} NMR spectrum of 14 in C 6 D 6 Figure A 66 1 H{ 13 C} gHMBC NMR spectrum of 14 in C 6 D 6

PAGE 240

240 Figure A 67 19 F{ 13 C} gHSQC NMR spectrum of 14 in C 6 D 6 Figure A 68 1 H NMR spectrum of 15 in C 6 D 6

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241 Figure A 69 19 F{ 1 H} NMR spectrum of 15 in C 6 D 6 Figure A 70 13 C{ 1 H} NMR spectrum of 15 in C 6 D 6

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242 Figure A 71 1 H{ 13 C} gHMBC NMR spectrum of 15 in C 6 D 6 Figure A 72 1 H{ 15 N} gHMBC NMR spectrum of 15 in C 6 D 6

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243 Figure A 73 19 F{ 13 C} gHMBC NMR spectrum of 15 in C 6 D 6 Figure A 74 19 F{ 13 C} gHSQC NMR spectrum of 15 in C 6 D 6

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244 Figure A 75 1 H NMR spectrum of 1 2 in C 6 D 6 and 15 equiv. of MeCN. ( t BuCCMe = 1.54 and 1.20 ppm; 14 = 3.13 and 1.18 ppm). Figure A 76 19 F{ 1 H} NMR spectrum of 1 2 in C 6 D 6 and 15 equiv. of MeCN (blue) along with 19 F{ 1 H} NMR spectrum of 14 (red)

PAGE 245

245 Figure A 77 Labelling scheme for 1 H and 13 C NMR peaks. Table A 2 1 H, 13 C, 19 F and 15 N chemical shifts in compounds 8,16 20 in C 6 D 6 Compd. 8 16 1 7 a 1 8 c 19 20 C1 80.6 82.9 83.6 83.8 83.1 84.1 C2 120.9 123.5 121.0 122.8 123.1 123.3 C3 143.0 146.1 154.2 145.3 145.8 145.8 C4 12 6.1 123.0 123.3 124.0 123.6 124.7 C5 132.1 131.1 130.3 131.6 131.0 132.6 C6 134.4 133.8 123.0 133.2 134.0 132.9 C7 128.3 126.3 127.2 126.9 126.4 126.9 C8 123.2 124.6 125.8 124.2 124.3 nm C9 123.3 123.6 124.8 123.6 123.4 nm C10 20.2 20.1 20.5 20.2 20. 0 20.0 C11 80.6 83.8 85.6 83.6 84.0 84.6 C12 120.9 126.8 130.9 126.5 126.9 127.4 C13 143.0 145.2 156.3 142.8 145.0 144.8 C14 126.1 123.9 125.0 126.9 123.7 nm C15 132.1 132.3 129.9 131.9 132.0 132.9 C16 134.4 134.5 127.1 134.2 134.5 134.7 C17 128.3 1 27.4 127.2 127.3 127.2 126.7 C18 123.2 124.4 125.3 124.0 124.3 nm C19 123.3 123.8 125.1 123.7 123.5 nm C20 20.2 20.3 20.7 20.4 20.2 20.2

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246 Table A 2 Continued Compd. 8 16 17 a 18 c 19 20 C21 259.6 280.6 284.3 262.1 82.0 C22 32.9 38.6 34.0 31.3 2 6.2 C23 20.7 17.1 18.4 20.6 18.6 C24 89.5 77.8 89.9 C25 29.1 33.5 29.1 0.1 N 66.2 232.1 148.3 217.8 234.2 232.5 H4 6.69 6.56 7.30 6.54 6.51 6.48 H5 6.63 6.63 6.90 6.61 6.61 6.65 H7 7.47 7.69 7.76 7.67 7.68 7.49 H10 1.83 1.97 2.21 1.93 1.97 1.90 H14 6.69 6.55 7.61 6.71 6.53 6.70 H15 6.63 6.78 7.04 6.76 6.76 6.59 H17 7.47 7.68 7.92 7.65 7.66 7.48 H20 1.83 1.93 2.28 1.93 1.93 1.87 H21 7.32 7.20 2.99, 2.95 H22 5.05, 4.76 4.42, 4.38 4.62, 4.50 5.28, 4.91 2.69, 2.58 H23 0.74 0.88 0.70 0.67 0.89 H25 1.18 1.76 1.19 0.12 F8 e 74.16 71.06 70.99 71.10 71.30 70.85 F9 75.69 73.44 73.53 75.63 73.90 73.70 F18 74.16 70.71 68.97 70.83 70.50 68.99 F19 75.69 76.73 75.97 76.28 76.60 75.96 a H26=2.49 ppm, H28=7.12 ppm, H29=16 ppm, H30=7.23 ppm, and C26=8.5 ppm, C27=118.5 ppm, C28=132.5 ppm, C29=130.0 ppm, C30=134.6 ppm. b H26=2.33 ppm, H28=6.99 ppm, H29=6.99 ppm, H30=7.07 ppm, and C26=8.5 ppm, C27=118.7 ppm, C28=132.5 ppm, C29=129.9 ppm, C30 =134.6 ppm. c the methyl in position 26 has H=4.87 ppm and C=23.5 ppm. d Not measured, the sample was too dilute. e The fluorine signals in compounds 16 20 are quartets with a typical coupling constant of 9 10 Hz. In compound 8 the signals are broad due to a fluxional process in the ligand, as demonstrated by the spectrum at 70 C. Compounds 8 16 20 were characterized by 1 H, 13 C, 19 F and 15 N NMR. The chemical shifts are presented in Table A 2 The assignments were made primarily based on the cross pea ks seen in the 1 H 13 C gHMBC spectra. The chemical shifts of the fluorinated carbons were measured in the 19 F 13 C gHSQC spectra, and their assignment to positions 8 and 9 vs. 18 and 19 was made based on the long range coupling of the fluorines to the quater nary carbon two bonds away, coupling seen in the 19 F 13 C gHMBC spectra. The chemical shift of the 15 N was measured in the 1 H 15 N

PAGE 247

247 gHMBC spectrum, where it shows cross peaks with H4 and H14. In the case of compounds 16 and 20 it also shows cross peaks with H21, which confirms the structural integrity of these compounds. No stereochemical assignments were made, i.e. H7 and H17 are interchangeable, as well as C8 and C9. In Table A 2 C1 and C2 were assigned as the most shielded of the pairs C1, C11 and C2, C1 2; F8 and F9 were assigned as the most deshielded of the pairs F8, F18 and F9, F19. In a typical assignment procedure, H7 displays cross peaks with a carbon around 20 ppm, assigned as C10, with a carbon between 80 85 ppm, assigned as C1, with a carbon betw een 150 160 ppm, assigned as C3 and with a carbon at approx 130 ppm, assigned as C5. H10, H5 and C7 were then identified by one bond correlations, or by the couplings H10 C5, H10 C7, H5 C7. H4 was identified as coupling with H5, or by its coupling with C6, the third carbon coupling with H10. One coupling of F8 or F9 with C1 was sufficient to identify these fluorines, since the pairs H8 F9 and F18 F19 are revealed by selective decoupling in the 19 F spectra. The assignments for the positions 11 20 was done in a similar way to the one for positions 1 10. The proton signals for positions 21 27 can be assigned based on their intensity and multiplicity. The carbons in these positions were assigned based on their one bond and long range couplings to protons. The 13 C chemical shifts difference in positions 3/13and 6/16 as well as the 15 N chemical shifts difference between compounds 17 compared to 16 18 19 and 20 suggest that in 17 16 18 19 and 20 it is an amido.

PAGE 248

248 Fi gure A 78 1 H NMR (C 6 D 6 300 MHz) spectrum of 16 Figure A 79 19 F{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 16

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249 Figure A 80 19 F{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 16 with selective decoupling at 73.9 ppm. Figure A 81 13 C{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 16

PAGE 250

250 Figure A 82 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz) spectrum of 16 expanded. Figure A 83 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz) spectrum of 16 full.

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251 Figure A 84 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded. Figure A 85 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded.

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252 Figure A 86 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 full. Figure A 87 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded.

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253 Figure A 88 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded. Figure A 89 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded.

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254 Figure A 90 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 16 Figur e A 91 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded.

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255 Figure A 92 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 16 expanded. Figure A 93 19 F 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 16 expanded.

PAGE 256

256 Figure A 94 1 H NMR (C 6 D 6 300 MHz) spectrum of 1 7 Figure A 95 19 F{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 1 7

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257 Figure A 96 31 P{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 1 7 Figure A 97 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 1 7

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258 Figure A 98 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 1 7 Figure A 99 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 1 7 expanded.

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259 Figure A 100 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 1 7 expanded. Figure A 101 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum o f 1 7 expanded.

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260 Figure A 102 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 1 7 expanded. Figure A 103 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 1 7

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261 Figure A 104 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 1 7 expanded. Figure A 105 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 1 7 expanded.

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262 Figure A 106 19 F 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 1 7 expanded Figure A 107 1 H NMR (C 6 D 6 500 MHz) spectrum of 1 8

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263 Figure A 108 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz) spectrum of 1 8 Figure A 109 1 H 1 H gDQFCOSY (C 6 D 6 500 MHz ) spectrum of 1 8 expanded.

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264 Figure A 110 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 1 8 expanded. Figure A 111 1 H 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 1 8 expanded.

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265 Figure A 112 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 1 8 expanded. Figure A 113 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 1 8 expanded.

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266 Figure A 114 19 F{ 1 H} NMR (C 6 D 6 500 MHz) spectru m of 1 8 Figure A 115 19 F 19 F gDQFCOSY (C 6 D 6 500 MHz) spectrum of 1 8

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267 Figure A 116 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 1 8 expanded. Figure A 117 19 F 13 C gHSQC (C 6 D 6 500 MHz) spectrum of 1 8 expanded.

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268 Figure A 118 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 1 8 Figure A 119 1 H NMR (C 6 D 6 500 MHz) spectrum of 1 9

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269 Figure A 120 1 H 1 H gDQCOSY (C 6 D 6 500 MHz) spectrum of 1 9 Figure A 121 1 H 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded.

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270 Figure A 122 1 H 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded. Figure A 123 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 1 9

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271 Figure A 124 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded. Figure A 125 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded.

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272 Figure A 126 1 H 13 C gHMBCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded. Figure A 127 1 H 15 N gHMBCAD (C 6 D 6 500 MHz) spectrum of 1 9 exp anded.

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273 Figure A 128 19 F{ 1 H} NMR (C 6 D 6 500 MHz) spectrum of 1 9 Figure A 129 19 F 19 F gDQCOSY (C 6 D 6 500 MHz) spectrum of 1 9

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274 Figure A 130 19 F 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded. Figure A 131 19 F 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded.

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275 Figure A 132 19 F 13 C gHSQCAD (C 6 D 6 500 MHz) spectrum of 1 9 expanded. Figure A 133 1 H NMR (C 6 D 6 300 MHz) spectrum of 20

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276 Figure A 134 19 F NMR (C 6 D 6 300 MHz) spectrum of 20 Figure A 135 13 C{ 1 H} NMR (C 6 D 6 300 MHz) spectrum of 20

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277 F igure A 136 1H 13C gHMBC (C6D6, 500 MHz) spectrum of 20 expanded. Figure A 137 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 20 expanded.

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278 Figure A 138 1 H 13 C g HMBC (C 6 D 6 500 MHz) spectrum of 20 expanded. Figure A 139 1 H 13 C gHMBC (C 6 D 6 500 MHz) spectrum of 20 expanded.

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279 Figure A 140 1 H 15 N gHMBC (C 6 D 6 500 MHz) spectrum of 20 Figure A 141 19 F{ 1 H} NMR (C 6 D 6 500 MHz) spectrum of 20 (bottom) and spectra with selective homonuclear decoupling (top).

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280 Figure A 142 1 H NMR (C DCl 3 500 MHz) spectrum of 2 2 Figure A 143 1 3 C { 1 H} NMR (C DCl 3 500 MHz) spectrum of 22

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281 Figure A 144 1 H NMR (C DCl 3 500 MHz) spectrum of 23 Figure A 145 1 H NMR (C DCl 3 500 MHz ) spectrum of 23

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282 A. 2 IR Data Figure A 146 IR spectrum of 2 (thin film) Figure A 147 IR spectrum of 3 (thin fil m).

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283 Figure A 148 IR spectrum of 4 (thin film) Figure A 149 Infrared s pectrum of 5 (thin film )

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284 Figure A 150 IR spectrum of 6 (thin film). Figure A 151 IR spectrum of 8 ( thin film)

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285 Figure A 152 IR spectrum of 16 ( thin film) Figure A 153 IR spectrum of 1 7 ( thin film)

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286 A. 3 UV Vis Data Figure A 154 UV vis spectra of 5 in toluene (1.79 and 8.94 x10 5 M) Figure A 155 UV vis of 6 in THF (0.057 mM, red; 0.113 mM, blue). 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 250 450 650 850 AU (nm) 0.057 mM [tBuOCO]CrO(CH2PPh3) 0.113 mM [tBuOCO]CrO(CH2PPh3)

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287 A. 4 MS Data Figure A 156 DART mass s pectroscopy spectra of 18 OPPh 3 Figure A 157 ESI TOF m ass s pectroscopy spectra of 8

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288 Figure A 158 GC CI m ass s pectroscopy spectra of 22 Figure A 159 ESI m ass s pectrosc opy spectra of 23

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289 A. 5 EPR Data Figure A 160 EPR spectrum of 3 (10 mM solution, toluene) at T = 298 K. Figure A 161 Procedure used to simulate the high frequency (240 GHz) powder EPR spect rum at T = 4.5 K. Individually simulated spectra of an S = 2 (a) and an S = 1.5 (b) systems are added together to get the total spectrum (c) corresponding to the mixture of the dimer ( 4 ) and monomer ( 2 )

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290 Figure A 162 Solut ion EPR of a mixture of 3 and 3 a (5.0 x10 3 M) in toluene ( blue ) and a 3 and 3 a solution (1.6 x10 3 M) in toluene ( blue ) with the addition of 6 equiv. MeCN ( red ) A.6 CV Data Figure A 163 Cyclic voltammograms of 5 x10 3 M solution of 2 4 and 5 in 0.1 M TBAH/CH 2 Cl 2 at 100 mVs 1 ; glassy carbon working and Ag/Ag + reference electrodes. 3.53E+03 3.55E+03 3.57E+03 3.59E+03 toluene acetonitrile

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291 A. 7 X Ray Crystallographic Data Figure A 164 Molecular structure of 1 Hydrogen atoms are omitted for clarity. X ray experimental : Data were collected at 173 K on a Siemens SMART PLATFORM equipped with A CCD area detector and a graphite monochromator utilizing MoK radiation ( = 0.71073 ). Cell parameters were refined using up to 8192 reflections. A fu ll sphere of data (1850 frames) was collected using the scan method (0.3 frame width). The first 50 frames were re measured at the end of data collection to monitor instrument and crystal stability (maximum correction on I was < 1 %). Absorption corre ctions by integration were applied based on measured indexed crystal faces. The structure was solved by the Direct Methods in SHELXTL6, and refined using full matrix least squares. The non H atoms were treated anisotropically, whereas the

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292 hydrogen atoms w ere calculated in ideal positions and were riding on their respective carbon atoms. The coordinated THF molecule is disordered in three parts and was refined as such with the site occupation factors dependently refined. All three THF parts were constrain ed to maintain similar geometries. The largest electron density peak, 1.57 e. 3 is within 0.92 A from K1 and could not be resolved as a disordered site, thus it was attributed to its anisotropy. A total of 328 parameters were refined in the final cycle of refinement using 4418 1 and wR 2 of 7.37% and 22.03%, respectively. Refinement was done using F 2

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293 Table A 3 Crystal data, structure solution and refinement for 1 Item Value identifi cation code jf05 empirical formula C 30 H 36 K 2 O 3 formula weight 522.79 T (K) 173(2) () 0.71073 crystal system Monoclinic space group C2/c a () 18.3698(16) b () 18.2304(15) c () 16.6555(14) (deg) 90 (deg) 94.661(2) (deg) 90 V ( 3 ) 5559.3(8) Z 8 calcd (Mg mm 3 ) 1.249 crystal size (mm 3 ) 0.17 x 0.14 x 0.13 abs coeff (mm 1 ) 0.369 F(000) 2224 range for data collection 1.58 to 27.50 limiting indices no. of reflns collcd 18576 no. of ind reflns (Ri nt) 6361 (0.0591) Completeness to = 27.50 99.70% absorption corr Integration refinement method Full matrix least squares on F2 data / restraints / parameters 6361 / 61 / 328 R 1, a wR 2 b 0.0737, 0.2203 [4418] R 1, a wR 2 b (all data) 0.0977, 0. 2376 GOF c on F 2 1.053 largest diff. peak and hole 1.569 and 0.662 e. 3 2 Fc 2 ) 2 2 ) 2 ]] 1/2 2 Fc 2 ) 2 ] / (n p)] 1/2 2 (Fo 2 )+(m*p) 2 +n*p], p = [max(Fo 2 ,0)+ 2* Fc 2 ]/3, m & n are constants.

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294 Table A 4 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 1 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) K2 1398(1) 1760(1) 9022(1) 53(1) K1 1006(1) 3250(1) 7491(1) 44(1) O1 195(1) 2538(1) 8596(2) 45(1) O2 2154(1) 2743(1) 8328(1) 40(1) C1 1178(2) 3756(2) 9188(2) 35(1) C2 1781(2) 4132(2) 8928(2) 36(1) C3 1647(2) 4804(2) 8529(2) 45(1) C4 954(2) 5071(2) 8382(2) 51(1) C5 35 6(2) 4680(2) 8632(2) 44(1) C6 464(2) 4016(2) 9038(2) 36(1) C7 175(2) 3594(2) 9288(2) 37(1) C8 270(2) 2843(2) 9047(2) 36(1) C9 927(2) 2488(2) 9257(2) 40(1) C10 1404(2) 2870(3) 9701(3) 59(1) C11 1293(2) 3584(3) 9947(3) 73(1) C12 680(2) 3948(2) 9722(3) 57(1) C13 2534(2) 3832(2) 9025(2) 37(1) C14 2684(2) 3133(2) 8681(2) 36(1) C15 3436(2) 2895(2) 8716(2) 42(1) C16 3974(2) 3353(2) 9074(2) 46(1) C17 3815(2) 4032(2) 9397(2) 48(1) C18 3103(2) 4270(2) 9370(2) 44(1) C19 1092(2) 1690(2) 8988(2) 46(1) C20 1836(2 ) 1425(2) 9242(3) 59(1) C21 501(2) 1175(2) 9376(3) 69(1) C22 1123(2) 1600(2) 8072(2) 53(1) C23 3646(2) 2177(2) 8302(2) 52(1) C24 4459(2) 1991(3) 8469(3) 73(1) C25 3215(2) 1522(2) 8557(3) 63(1) C26 3490(2) 2280(3) 7384(2) 67(1) O3 1461(12) 254(9) 8426(14) 65(1) C27 1958(9) 72(11) 7895(13) 85(3) C28 1404(13) 598(16) 7454(13) 140(5) C29 705(10) 557(18) 7908(16) 159(7) C30 947(14) 251(13) 8751(13) 99(3) O3' 1408(7) 302(6) 8509(11) 65(1) C27' 2058(7) 37(7) 8243(11) 85(3) C28' 1844(9) 850(7) 8189(18) 140( 5) C29' 1065(9) 912(7) 8450(17) 159(7) C30' 746(7) 133(8) 8438(13) 99(3) O3" 1728(6) 285(5) 8611(7) 65(1) C27" 2384(6) 153(7) 8775(10) 85(3) C28" 2162(10) 840(11) 8277(18) 140(5) C29" 1329(9) 771(14) 8063(17) 159(7) C30" 1068(7) 158(9) 8609(15) 99(3)

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295 Table A 5 Bond lengths (in ) for 1 Bond Length Bond Length K2 O2 2.596(2) K2 O1 2.673(3) K 2 O3' 2.792(10) K2 O3" 2.852(10) K2 O3 2.924(15) K2 C17#1 3.057(4) K2 C16#1 3.305(4) K2 C18#1 3.338(3) K2 C22#2 3.494(4) K2 C14 3.520(3) K2 K1 3.7543(11) K2 H1 2.93(3) K1 O2 2.601(2) K1 O1 2.780(2) K1 C8#2 2.895(3) K1 C1 2.966(3) K1 O1#2 3.0 29(3) K1 C2 3.128(3) K1 C6 3.162(3) K1 C22#2 3.162(4) K1 C9#2 3.218(3) K1 C7#2 3.282(3) K1 C3 3.474(3) K1 C5 3.492(3) O1 C8 1.307(4) O1 K1#2 3.029(3) O2 C14 1.306(4) C1 C6 1.399(4) C1 C2 1.400(4) C1 H1 0.99(3) C2 C3 1.405(5) C2 C13 1.485(5) C3 C4 1.366(5) C4 C5 1.400(5) C5 C6 1.393(5) C6 C7 1.489(4) C7 C12 1.382(5) C7 C8 1.433(4) C7 K1#2 3.282(3) C8 C9 1.437(4) C8 K1#2 2.895(3) C9 C10 1.381(5) C9 C19 1.544(5) C9 K1#2 3.219(3) C10 C11 1.374(6) C11 C12 1.386(6) C13 C18 1.401(4) C 13 C14 1.433(5) C14 C15 1.445(5) C15 C16 1.392(5) C15 C23 1.542(5) C16 C17 1.390(5) C16 K2#1 3.305(4) C17 C18 1.375(5) C17 K2#1 3.057(4) C18 K2#1 3.338(3) C19 C22 1.531(5) C19 C21 1.538(5) C19 C20 1.541(5) C22 K1#2 3.162(4) C22 K2#2 3.494(4) C23 C25 1.513(6) C23 C24 1.535(5) C23 C26 1.544(5) O3 C27 1.449(5) O3 C30 1.454(5) C27 C28 1.541(5) C28 C29 1.543(5) C29 C30 1.543(5) O3' C27' 1.445(5) O3' C30' 1.449(5) C27' C28' 1.534(5) C28' C29' 1.533(5) C29' C30' 1.536(5) O3" C27" 1.454( 5) O3" C30" 1.456(5) C27" C28" 1.538(5) C28" C29" 1.547(5) C29" C30" 1.542(5) Symmetry transformations used to generate equivalent atoms: Table A 6 Bond angles () for 1 Bond Angle Bond Angle O2 K2 O1 88.61(7) O2 K2 O3' 120.3(3) O1 K2 O3' 116.8(4) O2 K2 O3" 114.4(2) O1 K2 O3" 128.6(2) O3' K2 O3" 12.1(4) O2 K2 O3 117.4(3) O1 K2 O3 117.6(5) O3' K2 O3 2.9(6) O3" K2 O3 11.0(5) O2 K2 C17#1 145.09(9) O1 K2 C17#1 108.59(9) O3' K2 C17#1 79.5(4) O3" K2 C17#1 78.8(2) O3 K2 C17#1 82.0(4) O2 K2 C16#1 129.02(9) O1 K2 C16#1 93.27(8) O3' K2 C16#1 104.0(4)

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296 Table A 6 Continued. Bond Angle Bond Angle O3" K2 C16#1 103.7(2) O3 K2 C16#1 106.5(4) C17#1 K2 C16#1 24.85(10) O2 K2 C18#1 128.57(8) O1 K2 C18#1 132.75(8) O3' K2 C18#1 72.6(4) O3" K 2 C18#1 67.2(2) O3 K2 C18#1 74.2(5) C17#1 K2 C18#1 24.32(9) C16#1 K2 C18#1 42.22(9) O2 K2 C22#2 69.68(8) O1 K2 C22#2 74.35(8) O3' K2 C22#2 67.7(4) O3" K2 C22#2 72.5(2) O3 K2 C22#2 65.8(5) C17#1 K2 C22#2 143.37(10) C16#1 K2 C22#2 158.16(10) C18#1 K2 C22#2 1 39.64(9) O2 K2 C14 17.56(7) O1 K2 C14 97.51(7) O3' K2 C14 127.3(2) O3" K2 C14 118.3(2) O3 K2 C14 124.6(3) C17#1 K2 C14 127.53(9) C16#1 K2 C14 113.12(8) C18#1 K2 C14 112.65(8) C22#2 K2 C14 86.72(9) O2 K2 K1 43.80(5) O1 K2 K1 47.69(5) O3' K2 K1 119.1(4) O3" K2 K1 123.5(2) O3 K2 K1 117.4(5) C17#1 K2 K1 153.62(8) C16#1 K2 K1 130.80(7) C18#1 K2 K1 167.63(7) C22#2 K2 K1 51.58(6) C14 K2 K1 58.00(5) O2 K2 H1 61.0(6) O1 K2 H1 59.0(6) O3' K2 H1 175.7(7) O3" K2 H1 172.1(6) O3 K2 H1 175.7(8) C17#1 K2 H1 101.5(7) C16#1 K2 H1 76.8(7) C18#1 K2 H1 110.0(6) C22#2 K2 H1 110.1(6) C14 K2 H1 55.3(6) K1 K2 H1 58.5(6) O2 K1 O1 86.26(7) O2 K1 C8#2 133.12(8) O1 K1 C8#2 103.29(8) O2 K1 C1 65.21(8) O1 K1 C1 62.39(8) C8#2 K1 C1 158.35(9) O2 K1 O1#2 133.45(7) O1 K1 O1#2 78.03(8) C8#2 K1 O1#2 25.37(8) C1 K1 O1#2 136.01(8) O2 K1 C2 58.26(8) O1 K1 C2 88.22(8) C8#2 K1 C2 163.60(9) C1 K1 C2 26.39(8) O1#2 K1 C2 160.29(8) O2 K1 C6 90.90(8) O1 K1 C6 56.35(7) C8#2 K1 C6 132.77(9) C1 K1 C6 26.15(8) O1#2 K1 C6 114.46(7) C2 K1 C6 45.86(8) O2 K1 C22# 2 75.50(9) O1 K1 C22#2 78.79(9) C8#2 K1 C22#2 62.12(9) C1 K1 C22#2 125.05(10) O1#2 K1 C22#2 58.63(9) C2 K1 C22#2 132.70(9) C6 K1 C22#2 134.05(9) O2 K1 C9#2 107.85(8) O1 K1 C9#2 114.22(8) C8#2 K1 C9#2 26.53(8) C1 K1 C9#2 171.88(9) O1#2 K1 C9#2 45.37(7) C2 K 1 C9#2 153.89(9) C6 K1 C9#2 159.03(8) C22#2 K1 C9#2 47.21(9) O2 K1 C7#2 148.11(8) O1 K1 C7#2 116.88(8) C8#2 K1 C7#2 25.87(8) C1 K1 C7#2 143.77(9) O1#2 K1 C7#2 43.93(7) C2 K1 C7#2 137.84(8) C6 K1 C7#2 119.80(8) C22#2 K1 C7#2 87.27(9) C9#2 K1 C7#2 44.14(8) O 2 K1 C3 78.20(8) O1 K1 C3 103.27(8) C8#2 K1 C3 139.81(9) C1 K1 C3 42.80(8) O1#2 K1 C3 147.93(8) C2 K1 C3 23.84(8) C6 K1 C3 49.53(8) C22#2 K1 C3 153.44(10) C9#2 K1 C3 142.21(9) C7#2 K1 C3 114.00(8) O2 K1 C5 105.75(8) O1 K1 C5 76.32(8) C8#2 K1 C5 121.13(9)

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297 T able A 6 Continued. Bond Angle Bond Angle C1 K1 C5 42.61(8) O1#2 K1 C5 112.37(7) C2 K1 C5 49.79(8) C6 K1 C5 23.50(8) C22#2 K1 C5 154.92(10) C9#2 K1 C5 145.27(8) C7#2 K1 C5 101.17(8) C3 K1 C5 40.32(8) C8 O1 K2 129.6(2) C8 O1 K1 126.30(19) K2 O1 K1 86.99(7) C8 O1 K1#2 71.56(17) K2 O1 K1#2 158.73(10) K1 O1 K1#2 78.92(7) C14 O2 K2 125.57(19) C14 O2 K1 126.2(2) K2 O2 K1 92.50(7) C6 C1 C 2 122.2(3) C6 C1 K1 84.76(17) C2 C1 K1 83.28(17) C6 C1 H1 120.3(18) C2 C1 H1 117.5(18) K1 C1 H1 104.0(19) C1 C2 C3 117.4(3) C1 C2 C13 122.6(3) C3 C2 C13 119.9(3) C1 C2 K1 70.33(16) C3 C2 K1 92.0(2) C13 C2 K1 104.83(19) C4 C3 C2 121.3(3) C4 C3 K1 85.9(2) C2 C3 K1 64.15(17) C3 C4 C5 120.5(3) C6 C5 C4 120.2(3) C6 C5 K1 64.80(18) C4 C5 K1 84.7(2) C5 C6 C1 118.3(3) C5 C6 C7 120.0(3) C1 C6 C7 121.7(3) C5 C6 K1 91.7(2) C1 C6 K1 69.10(16) C7 C6 K1 107.88(18) C12 C7 C8 121.4(3) C12 C7 C6 118.9(3) C8 C7 C6 119.7(3) C 12 C7 K1#2 106.3(2) C8 C7 K1#2 61.81(16) C6 C7 K1#2 99.53(18) O1 C8 C7 119.8(3) O1 C8 C9 123.2(3) C7 C8 C9 116.6(3) O1 C8 K1#2 83.07(18) C7 C8 K1#2 92.32(19) C9 C8 K1#2 89.40(18) C10 C9 C8 119.0(3) C10 C9 C19 120.8(3) C8 C9 C19 120.2(3) C10 C9 K1#2 106.5(3 ) C8 C9 K1#2 64.07(16) C19 C9 K1#2 98.63(19) C11 C10 C9 123.5(3) C10 C11 C12 118.5(4) C7 C12 C11 120.8(4) C18 C13 C14 120.7(3) C18 C13 C2 119.5(3) C14 C13 C2 119.4(3) O2 C14 C13 120.2(3) O2 C14 C15 122.0(3) C13 C14 C15 117.7(3) O2 C14 K2 36.87(14) C13 C14 K2 114.53(19) C15 C14 K2 115.6(2) O2 C14 K1 36.44(15) C13 C14 K1 89.06(19) C15 C14 K1 145.9(2) K2 C14 K1 64.32(6) C16 C15 C14 118.7(3) C16 C15 C23 120.4(3) C14 C15 C23 120.7(3) C17 C16 C15 122.5(3) C17 C16 K2#1 67.5(2) C15 C16 K2#1 100.3(2) C18 C17 C16 119 .8(3) C18 C17 K2#1 89.4(2) C16 C17 K2#1 87.6(2) C17 C18 C13 120.6(3) C17 C18 K2#1 66.29(19) C13 C18 K2#1 99.0(2) C22 C19 C21 108.7(4) C22 C19 C20 106.2(3) C21 C19 C20 107.7(3) C22 C19 C9 112.4(3) C21 C19 C9 109.8(3) C20 C19 C9 111.9(3) C19 C22 K1#2 101.3(2 ) C19 C22 K2#2 167.4(3) K1#2 C22 K2#2 68.46(8) C25 C23 C24 107.3(4) C25 C23 C15 112.9(3) C24 C23 C15 112.5(3) C25 C23 C26 108.3(3) C24 C23 C26 107.8(3) C15 C23 C26 107.9(3) C27 O3 C30 115.4(11) C27 O3 K2 129.5(11) C30 O3 K2 115.0(10)

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298 Table A 6 Continued Bond Angle Bond Angle O3 C27 C28 97.0(9) C27 C28 C29 106.2(4) C28 C29 C30 106.0(4) O3 C30 C29 92.2(12) C27' O3' C30' 116.7(8) C27 O3' K2 121.8(8) C30' O3' K2 121.3(7) O3' C27' C28' 102.6(7) C29' C28' C27' 107.2(4) C28' C29' C30' 107.0(4) O3' C30' C29' 100.8(8) C27" O3" C30" 111.9(9) C27" O3" K2 131.5(8) C30" O3" K2 109.3(7) O3" C27" C28" 99.5(7) C27" C28" C29" 105.8(4) C30" C29" C2 8" 105.8(4) O3" C30" C29" 96.0(10) Symmetry transformations used to generate equivalent atoms: Table A 7 Anisotropic displacement parameters ( 2 x 10 3 ) for 1 The anisotropic displacement factor exponent takes the form: 2 a* b* U12 ] U 11 U 22 U 33 U 23 U 13 U 12 K2 55(1) 41(1) 64(1) 13(1) 23(1) 4(1) K1 49(1) 43(1) 38(1) 6(1) 1(1) 1(1) O1 45(1) 32(1) 58(1) 6(1) 17(1) 6(1) O2 38(1) 40(1) 43(1) 6(1) 5(1) 6(1) C1 43(2) 32(2) 30(1) 4(1) 4(1) 5(1) C2 45(2) 28(2) 34(2) 3(1) 3(1) 8(1) C3 52(2) 35(2) 48(2) 5(1) 3(2) 13(1) C4 63(2) 30(2) 59(2) 9(2) 4(2) 7(2) C5 51(2) 33(2) 48(2) 2(1) 1(2) 1(1) C6 44(2) 31(2) 34(2) 8(1) 5(1) 4(1) C7 40(2) 36(2) 35(2) 5(1) 4(1) 4(1) C8 39(2) 37(2) 31(1) 2(1) 4(1) 6(1) C9 39(2) 43(2) 36(2) 6(1) 1(1) 9(1) C10 44(2) 72(3) 64(2) 10(2) 17(2) 20(2) C11 54(2) 81(3) 90(3) 38(3) 34(2) 13(2) C12 52(2) 56(2) 65(2) 26(2) 19(2) 9(2) C13 41(2) 37(2) 33(2) 5(1) 6(1) 10(1) C14 38(2) 41(2) 30(1) 2(1) 8(1) 8(1) C15 42(2) 54(2) 31(2) 1(1) 7(1) 5(2) C16 35(2) 62(2) 41(2) 1(2) 3(1) 9(2) C17 43(2) 54(2) 47(2) 5(2) 4(1) 17(2) C18 51(2) 39(2) 43(2) 5(1) 1(1) 12(2) C19 46(2) 39(2) 53(2) 13(2) 3(2) 12 (1) C20 49(2) 55(2) 71(3) 18(2) 0(2) 19(2) C21 52(2) 49(2) 104(4) 29(2) 9(2) 9(2) C22 69(2) 32(2) 58(2) 6(2) 5(2) 12(2) C23 42(2) 69(3) 45(2) 13(2) 4(2) 7(2) C24 47(2) 96(3) 74(3) 28(3) 1(2) 14(2) C25 64(3) 53(2) 72(3) 13(2) 6(2) 6(2) C26 59(2) 101(4) 41(2) 22(2) 9(2) 7(2)

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299 Figure A 165 Molecular structure of 2 with ellipsoids drawn at the 50% probability level and two THF lattice solvent molecule s are removed for clarity. X ray experimental : Data were collected at 173 K on a Siemens SMART PLATFORM equipped with A CCD area detector and a graphite monochromator utilizing MoK radiation ( = 0.71073 ). Cell parameters were refined using up to 8192 reflections. A full sphere of data (1850 frames) was collected using the scan method (0.3 frame width). The first 50 frames were re measured at the end of data collection to m onitor instrument and crystal stability (maximum correction on I was < 1 %). Absorption corrections by integration were applied based on measured indexed crystal faces. The structure was solved by the Direct Methods in SHELXTL6, and refined using full mat rix least squares. The non H atoms were treated anisotropically, whereas the hydrogen atoms were calculated in ideal positions and were riding on their respective carbon atoms. There are two thf solvent molecules in the asymmetric unit in, addition to th e Cr complex. Two of the three coordinated thf molecules have three of the C atoms

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300 disordered and were refined in two parts with their site occupation factors adding up to 1.00. One solvent molecule is wholly disordered while the second has only two C at oms disordered. They were treated in the same manner like the coordinated thf molecules. A total of 484 parameters were refined in the final cycle of refinement using 6265 reflections with I > 2 (I) to yield R 1 and wR 2 of 5.22 % and 12.20 %, respectively. Refinement was done using F 2 SHELXTL6 (2000). Bruker AXS, Madison, Wisconsin, USA. Table A 8 Crystal data and structure refinement for 2 Item Value Identificatio n code orei10 Empirical formula C46 H67 Cr O7 Formula weight 784.00 Temperature 100(2) K Wavelength 0.71073 Crystal system Monoclinic Space group P2(1)/c Unit cell dimensions a = 22.0077(19) = 90. b = 10.5772(9) = 91.428(1). c = 18.0096( 15) = 90. Volume 4191.0(6) 3 Z 4 Density (calculated) 1.243Mg/m 3 Absorption coefficient 0.322 mm 1 F(000) 1692 Crystal size 0.21 x 0.20 x 0.17 mm 3 Theta range for data collection 0.93 to 25.00. Index ranges Reflections c ollected 24248 Independent reflections 7343 [R(int) = 0.0310] Completeness to theta = 27.50 99.4 % Absorption correction None Max. and min. transmission 0.9457 and 0.9360 Refinement method Full matrix least squares on F 2 Data / restraints / parameters 7 343 / 0 / 484 Goodness of fit on F 2 1.040 Final R indices [I>2sigma(I)] R1 = 0.0522, wR2 = 0.1220 [6265] R indices (all data) R1 = 0.0619, wR2 = 0.1282 Largest diff. peak and hole 0.780 and 0.520 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants.

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301 Table A 9 Atomic coordinates ( x 10 4 ) and equiva lent isotropic displacement parameters ( 2 x 10 3 ) for 2 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) Cr1 2516(1) 4740(1) 2400(1) 12(1) O1 3312(1) 3987(2) 2423(1) 15(1) O2 1723(1) 5500(2) 2447(1) 15(1) O3 2548(1) 4641(2) 3617(1) 19(1) O4 2953(1) 6461(2) 2485(1) 17(1) O5 2077(1) 3024(2) 2411(1) 18(1) C1 2502(1) 4817(2) 1284(1) 14(1) C2 2124(1) 5717(2) 906(1) 16(1) C3 2119(1) 5745(3) 124(2) 21(1) C4 2502(1) 4976(3) 273(2) 23(1) C5 2883(1) 4129(3) 93(2) 21(1) C6 2876(1) 4005(2) 870(1) 17(1) C7 3515(1) 3117(2) 1957(1) 14(1) C8 3286(1) 3025(2) 1215(2) 17(1) C9 3459(1) 1982(3) 789(2) 21(1) C10 3870(1) 1092(3) 1054(2) 22(1) C11 4135(1) 1257(2) 1754(2) 20(1) C12 3977(1) 2251(2) 2215(2) 16(1) C13 4277(1) 2402(2) 299 4(2) 17(1) C14 4796(1) 1452(3) 3125(2) 23(1) C15 3809(1) 2170(3) 3601(2) 20(1) C16 4552(1) 3737(3) 3082(2) 22(1) C17 1503(1) 6429(2) 2021(1) 13(1) C18 1718(1) 6628(2) 1290(1) 16(1) C19 1529(1) 7725(3) 912(2) 19(1) C20 1119(1) 8559(3) 1202(2) 22(1) C21 871( 1) 8298(2) 1888(2) 18(1) C22 1047(1) 7248(2) 2306(1) 15(1) C23 760(1) 6994(2) 3063(1) 16(1) C24 251(1) 7936(3) 3229(2) 23(1) C25 1241(1) 7113(3) 3696(2) 23(1) C26 476(1) 5659(3) 3061(2) 21(1) C27 2089(1) 4048(3) 4065(2) 24(1) C28 2140(1) 4652(3) 4834(2) 26 (1) C29 2653(1) 5627(3) 4770(2) 24(1) C30 3010(1) 5150(3) 4118(2) 20(1) C31 2727(1) 7654(2) 2780(2) 22(1) C32 3190(3) 8612(6) 2678(5) 26(2) C33 3703(3) 7988(7) 2335(6) 31(2) C34 3537(4) 6656(8) 2140(5) 21(2) C32' 3079(3) 8666(6) 2333(6) 33(2) C33' 3612(3) 8046(6) 2046(6) 29(2) C34' 3449(4) 6746(7) 1978(5) 18(2) C35 2325(1) 1788(2) 2612(2) 22(1) C36 1802(2) 875(5) 2597(4) 25(2) C37 1271(3) 1617(6) 2314(5) 32(2) C38 1551(3) 2780(6) 1916(4) 19(2) C36' 1902(4) 850(8) 2230(7) 42(3) C37' 1357(3) 1533(6) 1974(5) 1 8(2) C38' 1455(4) 2896(8) 2104(6) 23(2) O6 828(1) 2097(3) 140(2) 63(1)

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302 Table A 9 Continued. Atom X Y Z U(eq) C39 295(2) 2050(4) 323(2) 59(1) C40 415(4) 2872(8) 944(5) 64(2) C41 899(3) 3757(7) 656(4) 47(2) C40' 70(4) 3482(8) 448(5) 46(2) C41' 611(5) 4218(10) 112(6) 65(3) C42 1059(2) 3330(4) 61(3) 62(1) O7 4042(3) 8255(7) 200(6) 45(2) C43 3955(5) 6900(9) 110(6) 28(3) C44 4201(5) 6263(10) 580(7) 45(3) C45 4729(6) 7058(13) 783(9) 59(4) C46 4603(5) 8222(11) 579(8) 43(3) O7' 4139(2) 8102(5) 128(4) 48( 2) C43' 3832(4) 6983(7) 103(5) 47(2) C44' 4342(3) 6062(6) 233(4) 39(2) C45' 4853(3) 6852(6) 518(4) 34(2) C46' 4676(3) 8211(6) 305(5) 38(2) Table A 10 Bond lengths [] for 2 Bond Length Bond Length Cr1 O1 1.9227(17) Cr1 O2 1.9248(17) Cr1 C1 2.011(3) Cr1 O5 2.0566(18) Cr1 O4 2.0624(18) Cr1 O3 2.1938(18) O1 C7 1.331(3) O2 C17 1.331(3) O3 C30 1.446(3) O3 C27 1.449(3) O4 C34 1.458(8) O4 C31 1.461(3) O4 C34' 1.472(7) O5 C35 1.459(3) O5 C38 1.466(6) O5 C38' 1.469(8) C1 C6 1.414(4) C1 C2 1.426(4) C2 C3 1.408(4) C2 C18 1.494(4) C3 C4 1.384(4) C4 C5 1.383(4) C5 C6 1.406(4) C6 C8 1.49 9(4) C7 C8 1.419(4) C7 C12 1.436(4) C8 C9 1.402(4) C9 C10 1.381(4) C10 C11 1.388(4) C11 C12 1.389(4) C12 C13 1.544(4) C13 C14 1.536(4) C13 C15 1.541(4) C13 C16 1.542(4) C17 C18 1.426(4) C17 C22 1.431(4) C18 C19 1.402(4) C19 C20 1.375(4) C21 C 22 1.391(4) C22 C23 1.541(4) C23 C24 1.533(4) C23 C25 1.541(4) C23 C26 1.544(4) C27 C28 1.527(4) C28 C29 1.535(4) C29 C30 1.514(4) C31 C32 1.451(7) C31 C32' 1.557(8) C32 C33 1.458(9) C33 C34 1.495(10) C32' C33' 1.450(9) C33' C34' 1.426(10) C3 5 C36 1.501(6) C35 C36' 1.514(9) C36 C37 1.486(8) C37 C38 1.558(9) C36' C37' 1.464(10) C37' C38' 1.475(11) O6 C42 1.409(5) O6 C39 1.422(5) C39 C40 1.447(9) C39 C40' 1.607(10) C40 C41 1.501(10) C41 C42 1.405(8) C40' C41' 1.535(13) C41' C42 1.3 91(11) O7 C46 1.425(13) O7 C43 1.552(13)

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303 Table A 1 0 C ontinued Bond Length Bond Length C43 C44 1.527(15) C44 C45 1.488(16) C 45 C46 1.316(17) O7' C43' 1.420(9) O7' C46' 1.436(8) C43' C44' 1.509(10) C44' C45' 1.501(8) C45' C46' 1.541(9) Symmetry transformations used to generate equivalent atoms: Table A 11 Bond angles [] for 2 Bond Angle Bond Angle O1 Cr1 O2 176.20(8) O1 Cr1 C1 91.70(9) O2 Cr1 C1 92.08(9) O1 Cr1 O5 93.57(7) O2 Cr1 O5 86.62(7) C1 Cr1 O5 92.88(9) O1 Cr1 O4 86.67(7) O2 Cr1 O4 92.82(7) C1 Cr1 O4 91.96(9) O5 Cr1 O4 175.14(7) O1 Cr1 O3 87.27(7) O2 Cr1 O3 88.95(7) C1 Cr1 O3 178.98(9) O5 Cr1 O3 87.19(7) O4 Cr1 O3 87.97(7) C7 O1 Cr1 126.42(16) C17 O2 Cr1 126.86(16) C30 O3 C27 107.6(2) C30 O3 Cr1 127.58(16) C 27 O3 Cr1 124.85(16) C34 O4 C31 110.2(3) C34 O4 C34' 14.1(4) C31 O4 C34' 108.2(3) C34 O4 Cr1 120.5(3) C31 O4 Cr1 128.87(16) C34' O4 Cr1 119.0(3) C35 O5 C38 106.1(3) C35 O5 C38' 110.5(3) C38 O5 C38' 16.5(4) C35 O5 Cr1 128.35(15) C38 O5 Cr1 120.9(2) C38' O5 Cr1 120.8(3) C6 C1 C2 119.6(2) C6 C1 Cr1 120.50(19) C2 C1 Cr1 119.88(19) C3 C2 C1 118.7(2) C3 C2 C18 117.3(2) C1 C2 C18 123.9(2) C4 C3 C2 121.0(3) C5 C4 C3 120.2(3) C4 C5 C6 120.9(3) C5 C6 C1 119.3(2) C5 C6 C8 117.1(2) C1 C6 C8 123.6(2) O1 C7 C8 121.5(2) O 1 C7 C12 118.9(2) C8 C7 C12 119.6(2) C9 C8 C7 118.2(2) C9 C8 C6 119.1(2) C7 C8 C6 122.7(2) C10 C9 C8 122.2(3) C9 C10 C11 119.0(3) C10 C11 C12 122.1(3) C11 C12 C7 118.4(2) C11 C12 C13 120.8(2) C7 C12 C13 120.7(2) C14 C13 C15 107.1(2) C14 C13 C16 107.2(2) C1 5 C13 C16 109.9(2) C14 C13 C12 111.9(2) C15 C13 C12 110.5(2) C16 C13 C12 110.2(2) O2 C17 C18 121.2(2) O2 C17 C22 119.3(2) C18 C17 C22 119.6(2) C19 C18 C17 118.0(2) C19 C18 C2 118.8(2) C17 C18 C2 123.2(2) C20 C19 C18 122.4(3) C19 C20 C21 119.1(2) C20 C21 C2 2 122.0(2) C21 C22 C17 118.5(2) C21 C22 C23 120.2(2) C17 C22 C23 121.2(2) C24 C23 C22 112.1(2) C24 C23 C25 107.1(2) C22 C23 C25 110.6(2) C24 C23 C26 107.3(2) C22 C23 C26 109.4(2) C25 C23 C26 110.3(2) O3 C27 C28 106.7(2) C27 C28 C29 104.5(2) C30 C29 C28 103 .4(2) O3 C30 C29 103.8(2) C32 C31 O4 108.1(3) C32 C31 C32' 25.2(3) O4 C31 C32' 103.2(3) C31 C32 C33 106.9(5) C32 C33 C34 109.9(6) O4 C34 C33 104.2(5)

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304 Table A 1 1 Continued Bond Angle Bond Angle C33' C32' C31 106.9(5) C34' C33' C32' 105.2(6) C33' C34' O4 109.5(5) O5 C35 C36 106.9(3) O5 C35 C36' 104.6(4) C36 C35 C36' 26.9(4) C37 C36 C35 105.2(4) C36 C37 C38 105.0(5) O5 C38 C37 100.0(4 ) C37' C36' C35 108.0(6) C36' C37' C38' 108.5(6) O5 C38' C37' 106.3(6) C42 O6 C39 105.6(3) O6 C39 C40 105.5(5) O6 C39 C40' 107.2(4) C40 C39 C40' 52.2(5) C39 C40 C41 104.4(6) C42 C41 C40 106.1(6) C41' C40' C39 100.9(7) C42 C41' C40' 106.5(8) C41' C42 C41 54 .3(5) C41' C42 O6 113.1(6) C41 C42 O6 107.8(4) C46 O7 C43 105.4(7) C44 C43 O7 93.7(9) C45 C44 C43 104.2(9) C46 C45 C44 106.7(11) C45 C46 O7 110.4(10) C43' O7' C46' 107.5(5) O7' C43' C44' 103.5(6) C45' C44' C43' 105.1(5) C44' C45' C46' 103.7(5) O7' C46' C45 106.1(5) Symmetry transformations used to generate equivalent atoms: Table A 12 Anisotropic displacement parameters ( 2 x 10 3 ) for 2 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 Cr1 13(1) 10(1) 12(1) 0(1) 1(1) 1(1) O1 14(1) 15(1) 15(1) 3(1) 1(1) 3(1) O2 15(1) 14(1) 15(1) 2(1) 1(1) 3(1) O3 18(1) 27(1) 13(1) 2(1) 1(1) 1(1) O4 17(1) 13(1) 20(1) 2(1) 4(1) 0(1) O5 16(1) 13 (1) 23(1) 1(1) 3(1) 1(1) C1 14(1) 15(1) 14(1) 1(1) 1(1) 4(1) C2 14(1) 17(1) 15(1) 1(1) 0(1) 3(1) C3 22(1) 22(1) 18(1) 3(1) 2(1) 0(1) C4 31(2) 28(2) 11(1) 1(1) 0(1) 1(1) C5 23(1) 23(1) 17(1) 5(1) 3(1) 1(1) C6 16(1) 18(1) 17(1) 1 (1) 0(1) 3(1) C7 12(1) 11(1) 21(1) 2(1) 5(1) 2(1) C8 15(1) 17(1) 20(1) 2(1) 4(1) 2(1) C9 21(1) 22(1) 20(1) 5(1) 2(1) 2(1) C10 24(2) 16(1) 28(2) 8(1) 7(1) 1(1) C11 16(1) 15(1) 28(2) 2(1) 4(1) 2(1) C12 13(1) 13(1) 22(1) 2(1) 5(1) 2(1) C13 15(1) 16(1) 19(1) 2(1) 2(1) 2(1) C14 20(1) 25(2) 25(2) 1(1) 0(1) 5(1) C15 19(1) 21(1) 20(1) 1(1) 2(1) 2(1) C16 19(1) 20(1) 26(2) 2(1) 3(1) 2(1) C17 12(1) 12(1) 15(1) 1(1) 3(1) 3(1) C18 13(1) 17(1) 18(1) 2(1) 2(1) 3(1) C19 1 9(1) 21(1) 18(1) 5(1) 0(1) 2(1) C20 22(1) 18(1) 28(2) 8(1) 1(1) 2(1) C21 15(1) 16(1) 25(2) 2(1) 0(1) 2(1) C22 12(1) 15(1) 17(1) 0(1) 3(1) 3(1) C23 14(1) 17(1) 16(1) 2(1) 2(1) 1(1)

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305 Table A 1 2 Continued. U 11 U 22 U 33 U 23 U 13 U 12 C24 22(1) 23(2) 24(2) 1(1) 4(1) 5(1) C25 23(2) 29(2) 18(1) 2(1) 0(1) 4(1) C26 19(1) 20(1) 26(2) 3(1) 6(1) 1(1) C27 31(2) 22(2) 20(2) 2(1) 9(1) 2(1) C28 27(2) 32(2) 19(2) 2(1) 7(1) 3(1) C29 28(2) 27(2) 17(1) 4(1) 1(1) 4(1) C30 19(1) 24(1 ) 17(1) 0(1) 1(1) 3(1) C31 21(1) 14(1) 32(2) 7(1) 4(1) 4(1) C35 21(1) 12(1) 34(2) 4(1) 2(1) 3(1) O6 51(2) 48(2) 90(2) 7(2) 18(2) 5(1) C39 55(3) 68(3) 53(3) 19(2) 2(2) 17(2) C42 54(3) 46(2) 85(3) 13(2) 24(2) 14(2)

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306 Figure A 166 X ray structure of 3 with ellipsoids drawn at the 50% probability level X ray experimental : Data were collected at 173 K on a Siemens SMART PLATFORM equipped with A CCD area detector and a graphite monochromator utilizing MoK radiation ( = 0.71073 ). Cell parameters were refined using up to 8192 reflections. A full sphere of data (1850 frames) was collected using the scan method (0.3 frame width). The first 50 frames were re measured at the end of data collection t o monitor instrument and crystal stability (maximum correction on I was < 1 %). Absorption corrections by integration were applied based on measured indexed crystal faces. The structure was solved by the Direct Methods in SHELXTL6, and refined using full matrix least squares. The non H atoms were treated anisotropically, whereas the hydrogen atoms were calculated in ideal positions and were riding on their respective carbon atoms. A total of 316 parameters were refined in the final cycle of refinement

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307 us ing 3691 reflections with I > 2 (I) to yield R 1 and wR 2 of 4.08% and 8.66%, respectively. Refinement was done using F 2 SHELXTL6 (2000). Bruker AXS, Madison, Wisconsin, USA. Table A 13 Crystal data and structure refinement for 3 Item Value Identification code orei2 Empirical formula C 30 H 35 CrO 4 Formula weight 511.58 Temperature 100(2) K Wavelength 0.71073 Crystal system Monoclinic Space group P2(1)/n Unit cell dimensions a = 8.845(2) = 90. b = 11.774(3) = 9 2.553(4). c = 24.758(6) = 90. Volume 2575.8(10) 3 Z 4 Density (calculated) 1.319 Mg/m 3 Absorption coefficient 0.478 mm 1 F(000) 1084 Crystal size 0.33 x 0.06 x 0.03 mm 3 Theta range for data collection 1.65 to 26.14. Index ranges Reflections collected 16375 Independent reflections 5110 [R(int) = 0.0523] Completeness to theta = 27.50 99.6 % Absorption correction None Max. and min. transmission 0.9882 and 0.8598 Refinement method Full matrix least squares on F 2 Data / res traints / parameters 5110 / 0 / 316 Goodness of fit on F 2 1.027 Final R indices [I>2sigma(I)] R1 = 0.0408, wR2 = 0.0866 [3691] R indices (all data) R1 = 0.0695, wR2 = 0.0996 Largest diff. peak and hole 0.500 and 0.493 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants.

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308 Table A 14 Atomic coordinates ( x 10 4 ) and equivalent isotropic displ acement parameters ( 2 x 10 3 ) for 3 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) Cr1 5610(1) 919(1) 1734(1) 12(1) O1 6541(2) 1165(1) 2389(1) 14(1) O2 5782(2) 1771(1) 1128(1) 14(1) O3 7813(2) 260(1) 1529(1) 16(1) O4 4739(2) 234(1) 1656(1) 19(1) C1 3881(3) 1897(2) 1955(1) 13(1) C2 2999(3) 2477(2) 1554(1) 14(1) C3 1880(3) 3232(2) 1720(1) 18(1) C4 1628(3) 3397(2) 2258(1) 19(1) C5 2474(3) 2817(2) 2649(1) 16(1) C6 3595(3) 2041(2) 2506(1) 13(1) C7 5951(3) 1093(2) 2888(1) 13(1) C8 4459(3) 1450(2) 2951(1) 13(1) C9 3821(3) 1275(2) 3454(1) 16(1) C10 4671(3) 815(2) 3881(1) 17(1) C11 6175(3) 532(2) 3817(1) 16(1) C12 6866(3) 654(2) 3326(1) 14(1) C13 8520(3) 322(2) 3259(1) 17(1) C14 8598(3) 664(2) 2852(1) 24(1) C15 9416( 3) 1359(2) 3061(1) 22(1) C16 9304(3) 77(2) 3789(1) 22(1) C17 4651(3) 2096(2) 772(1) 13(1) C18 3229(3) 2377(2) 966(1) 14(1) C19 2049(3) 2629(2) 588(1) 17(1) C20 2295(3) 2669(2) 46(1) 20(1) C21 3736(3) 2467(2) 136(1) 17(1) C22 4949(3) 2173(2) 213(1) 14(1) C23 6533(3) 1961(2) 2(1) 16(1) C24 6552(3) 2114(2) 614(1) 22(1) C25 7659(3) 2823(2) 254(1) 20(1) C26 7061(3) 738(2) 124(1) 21(1) C27 8048(3) 912(2) 1358(1) 20(1) C28 9611(3) 933(2) 1137(1) 28(1) C29 10438(3) 1(2) 1460(1) 29(1) C30 9226(3) 893(2) 1506(1 ) 21(1) Table A 15 Bond length [] for 3 Bond Length Bond Length Cr1 O4 1.5683(18) Cr1 O1 1.80 98(17) Cr1 O2 1.8166(17) Cr1 C1 2.009(2) Cr1 O3 2.1781(17) O1 C7 1.364(3) O2 C17 1.359(3) O3 C30 1.459(3) O3 C27 1.461(3) C1 C6 1.410(3) C1 C2 1.411(4) C2 C3 1.405(3) C2 C18 1.483(3) C3 C4 1.376(4) C4 C5 1.378(4) C5 C6 1.405(3) C6 C8 1.485(3 ) C7 C8 1.401(3) C7 C12 1.421(3) C8 C9 1.405(3) C9 C10 1.381(4) C10 C11 1.387(4) C11 C12 1.393(3) C12 C13 1.530(3)

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309 Table A 1 5 Continued Bond Length Bond Length C13 C16 1.532(4) C13 C14 1.541(4) C13 C15 1.548(4) C17 C18 1.406(3) C17 C22 1.424(3) C18 C19 1.403(3) C19 C20 1.371(4) C20 C21 1.391(4) C21 C22 1.391(4) C22 C23 1.538(3) C23 C25 1.535(4) C23 C24 1.535(3) C23 C26 1.540(4) C27 C28 1.510(4) C28 C29 1.526(4) C29 C30 1.510(4) Symmetry transformations used to generate equivalent atoms: Table A 16 Bond angles [] for 3 Bond Angl es Bond Angles O4 Cr1 O1 116.73(9) O4 Cr1 O2 115.82(9) O1 Cr1 O2 126.89(8) O4 Cr1 C1 98.84(9) O1 Cr1 C1 89.21(9) O2 Cr1 C1 90.06(9) O4 Cr1 O3 95.88(8) O1 Cr1 O3 83.67(7) O2 C r1 O3 84.00(7) C1 Cr1 O3 165.27(8) C7 O1 Cr1 128.63(15) C17 O2 Cr1 127.20(15) C30 O3 C27 109.76(18) C30 O3 Cr1 127.16(14) C27 O3 Cr1 122.98(14) C6 C1 C2 120.3(2) C6 C1 Cr1 120.27(19) C2 C1 Cr1 119.37(17) C3 C2 C1 118.5(2) C3 C2 C18 117.7(2) C1 C2 C18 123.7 (2) C4 C3 C2 121.2(2) C3 C4 C5 120.3(2) C4 C5 C6 120.9(2) C5 C6 C1 118.8(2) C5 C6 C8 117.6(2) C1 C6 C8 123.6(2) O1 C7 C8 118.8(2) O1 C7 C12 119.0(2) C8 C7 C12 122.1(2) C7 C8 C9 118.2(2) C7 C8 C6 121.0(2) C9 C8 C6 120.8(2) C10 C9 C8 120.7(2) C9 C10 C11 120. 0(2) C10 C11 C12 122.3(2) C11 C12 C7 116.6(2) C11 C12 C13 121.8(2) C7 C12 C13 121.7(2) C12 C13 C16 112.6(2) C12 C13 C14 109.5(2) C16 C13 C14 107.3(2) C12 C13 C15 109.8(2) C16 C13 C15 107.2(2) C14 C13 C15 110.4(2) O2 C17 C18 119.2(2) O2 C17 C22 119.1(2) C18 C17 C22 121.6(2) C19 C18 C17 118.1(2) C19 C18 C2 120.5(2) C17 C18 C2 121.2(2) C20 C19 C18 121.0(2) C19 C20 C21 119.9(2) C20 C21 C22 122.3(2) C21 C22 C17 116.7(2) C21 C22 C23 121.3(2) C17 C22 C23 122.0(2) C25 C23 C24 106.9(2) C25 C23 C22 109.8(2) C24 C23 C 22 111.6(2) C25 C23 C26 110.7(2) C24 C23 C26 106.8(2) C22 C23 C26 111.0(2) O3 C27 C28 105.4(2) C27 C28 C29 102.9(2) C30 C29 C28 102.4(2) O3 C30 C29 105.0(2) Symmetry transformations used to generate equivalent atoms:

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310 Table A 17 Anisotropic displacement parameters ( 2 x 10 3 ) for 3 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 Cr1 12(1) 14(1) 11(1) 0(1) 1(1) 0(1) O1 12(1) 20(1) 11(1) 0(1) 0(1) 2(1) O2 11(1) 19(1) 12(1) 3(1) 1(1) 1(1) O3 14(1) 15(1) 19(1) 1(1) 3(1) 3(1) O4 21(1) 16(1) 20(1) 2(1) 3(1) 1(1) C1 11(1) 11(1) 16(1) 2(1) 2(1) 4(1) C2 11(1) 15(1) 15(1) 0(1) 1(1) 2(1) C3 17(1) 17(1) 20(1) 4(1) 0(1) 4(1) C4 15(1) 19(1) 22(1) 1(1) 4(1) 2(1) C5 17(1) 16(1) 15(1) 2(1) 4(1) 1(1) C6 11(1) 13(1) 16(1) 0(1) 1(1) 3(1) C7 17(1) 10(1) 11(1) 2(1) 1(1) 2(1) C8 15(1) 11(1) 13(1) 3(1) 0(1) 3(1) C9 17(1) 15(1) 16(1) 4(1) 1(1) 2(1) C10 21(1) 17(1) 13(1) 1(1) 4(1) 4(1) C11 23(2) 13(1) 12(1) 1(1) 6(1) 0(1) C12 16(1) 11(1) 15(1) 1(1) 3(1) 0(1) C13 17(1) 19(1) 14(1) 1(1) 1(1) 2(1) C14 25(2) 26(2) 20(1) 2(1) 0(1) 9(1) C15 15(1) 28(2) 23(2) 4(1) 1(1) 1(1) C16 21(2) 25(2) 20(1) 2(1) 2(1) 6(1) C17 13(1) 10(1) 16(1) 1(1) 2(1) 2(1) C18 14(1) 12(1) 16(1) 2(1) 0(1) 1(1) C19 11(1) 22(1) 19(1) 3(1) 1(1) 0(1) C20 16(1) 26(2) 17(1) 5(1) 6(1) 0(1) C21 19(1) 20(1) 13(1) 2(1) 0(1) 2(1) C22 16(1) 12(1) 14(1) 0(1 ) 1(1) 2(1) C23 15(1) 20(1) 12(1) 2(1) 2(1) 1(1) C24 20(2) 30(2) 16(1) 0(1) 4(1) 4(1) C25 13(1) 27(2) 20(1) 1(1) 2(1) 2(1) C26 21(2) 24(2) 19(1) 1(1) 5(1) 6(1) C27 24(2) 15(1) 21(1) 3(1) 3(1) 3(1) C28 28(2) 22(1) 34(2) 1(1) 9(1) 9(1) C29 17(2) 33(2) 36(2) 7(1) 5(1) 4(1) C30 17(1) 22(1) 24(1) 1(1) 4(1) 3(1)

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311 Figure A 167 Molecular structure of 4 with ellipsoids drawn at the 50% probability level and hydrogen atoms and an ether lattice molecule removed for clarity. X ray experimental : Data were collected at 173 K on a Siemens SMART PLATFORM equipped with A CCD area detector and a graphite monochromator utilizing MoK radiation ( = 0.71073 ). Cell parameters were refined using up to 8192 reflec tions. A full sphere of data (1850 frames) was collected using the scan method (0.3 frame width). The first 50 frames were re measured at the end of data collection to monitor instrument and crystal stability (maximum correction on I was < 1 %). Abso rption corrections by integration were applied based on measured indexed crystal faces. The structure was solved by the Direct Methods in SHELXTL6, and refined using full matrix least squares. The non H atoms were treated anisotropically, whereas the hyd rogen atoms were calculated in ideal positions and were riding on their respective carbon atoms. The molecules are located on 2 fold rotation axes, thus only half a

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312 molecule is in the asymmetric unit. There is also a disordered diethyl ether molecule in the asymmetric unit. The solvent molecule was refined in two parts with their site occupation factors dependently refined. A total of 353 parameters were refined in the final cycle of refinement using 5027 reflections with I > 2 (I) to yield R 1 and wR 2 of 5.18 % and 12.27 %, respectively. Refinement was done using F 2 SHELXTL6 (2000). Bruker AXS, Madison, Wisconsin, USA. Table A 18 X ray crystallographic structure parameters and refinement data for 4 Item Value empirical formula C 68 H 90 Cr 2 O 9 formula weight 1155.4 crystal system Monoclinic space group I2/a crystal dimensions (mm) 0.23 0.18 0.14 a () 24.7961(16) b () 11.9905(8) c () 21.8533(14) (deg) 104.6550(10) volume ( 3 ) 6286.0(7) Z () 4 absorption coeff (mm 1 ) 0.400 F (000) 2472 D calcd (g/cm 3 ) 1.221 0.71073 Temperature (K) 173(2) range (deg) 1.70 to 27.50 completeness to max 99.70% index ranges 5, reflections collected 20039 indep reflections [ R int ] 7215 [0.0525] data/restraints/param 7215/7/353 final R 1 indices [I > R1 = 0.0518, wR2 = 0.1227 [5027] R indices (all data) R1 = 0.0849, wR2 = 0.1345 largest dif f peak/hole e. 3 0.499/ 0.339 goodness of fit on F 2 0.989

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313 Table A 19 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacement parameters ( 2 x 10 3 ) for 4 U(eq) is defined as one third of the trace of the or thogonalized U ij tensor. Atom X Y Z U(eq) Cr1 1792(1) 605(1) 4671(1) 20(1) O1 1408(1) 1462(1) 5087(1) 27(1) O2 1490(1) 270(1) 3995(1) 23(1) O3 2500 336(2) 5000 26(1) O4 1574(1) 784(1) 5244(1) 29(1) C1 1866(1) 1872(2) 4114(1) 23(1) C2 1939(1) 1647(2) 3502 (1) 25(1) C3 1974(1) 2540(2) 3102(1) 32(1) C4 1931(1) 3623(2) 3290(1) 39(1) C5 1851(1) 3849(2) 3876(1) 36(1) C6 1822(1) 2986(2) 4302(1) 27(1) C7 1709(1) 3309(2) 4914(1) 30(1) C8 1809(1) 4393(2) 5147(1) 40(1) C9 1663(1) 4720(2) 5687(1) 48(1) C10 1392(1) 398 6(2) 5992(1) 42(1) C11 1280(1) 2896(2) 5793(1) 33(1) C12 1468(1) 2552(2) 5258(1) 28(1) C13 961(1) 2089(2) 6128(1) 37(1) C14 777(1) 2670(3) 6671(1) 51(1) C15 1337(1) 1107(3) 6414(1) 43(1) C16 430(1) 1681(3) 5652(1) 43(1) C17 1944(1) 502(2) 3247(1) 23(1) C18 2185(1) 295(2) 2742(1) 31(1) C19 2162(1) 738(2) 2471(1) 35(1) C20 1881(1) 1603(2) 2680(1) 33(1) C21 1632(1) 1464(2) 3181(1) 25(1) C22 1684(1) 401(2) 3474(1) 22(1) C23 1315(1) 2428(2) 3395(1) 29(1) C24 1271(1) 3448(2) 2955(1) 41(1) C25 1620(1) 2797( 2) 4065(1) 37(1) C26 715(1) 2066(2) 3365(1) 37(1) C27 1004(1) 1174(2) 5176(1) 38(1) C28 1053(1) 2210(3) 5566(2) 54(1) C29 1574(1) 2001(3) 6085(1) 54(1) C30 1946(1) 1385(2) 5749(1) 40(1) C31 168(3) 1108(6) 3496(4) 82(2) C32 316(6) 2236(10) 3489(9) 151( 7) O5 138(2) 2876(3) 3432(2) 70(2) C33 91(5) 4074(7) 3484(5) 129(4) C34 182(5) 4481(9) 4097(5) 121(4) C31' 272(4) 1210(8) 3148(5) 73(3) C32' 336(5) 2310(8) 3443(7) 50(4) O5' 175(3) 2977(6) 3877(4) 88(3) C33' 273(7) 4129(11) 3797(8) 121(6) C34' 170(7) 465 7(13) 4400(8) 119(6)

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314 Table A 20 Bond lengths [] for 4 Bond Length Bond Length Cr1 O3 1.7497( 5) Cr1 O1 1.7962(15) Cr1 O2 1.8129(15) Cr1 C1 1.983(2) Cr1 O4 2.2308(16) O1 C12 1.357(3) O2 C22 1.353(3) O3 Cr1#1 1.7496(5) O4 C30 1.440(3) O4 C27 1.460(3) C1 C6 1.411(3) C1 C2 1.419(3) C2 C3 1.400(3) C2 C17 1.483(3) C3 C4 1.374(4) C4 C5 1.3 72(4) C5 C6 1.406(3) C6 C7 1.486(3) C7 C8 1.395(3) C7 C12 1.406(3) C8 C9 1.376(4) C9 C10 1.377(4) C10 C11 1.384(4) C11 C12 1.425(3) C11 C13 1.546(4) C13 C15 1.534(4) C13 C16 1.536(4) C13 C14 1.540(3) C17 C18 1.405(3) C17 C22 1.412(3) C18 C19 1.367(3) C19 C20 1.389(3) C20 C21 1.397(3) C21 C22 1.418(3) C21 C23 1.535(3) C23 C25 1.534(3) C23 C26 1.536(3) C23 C24 1.543(3) C27 C28 1.494(4) C28 C29 1.509(4) C29 C30 1.509(4) C31 C32 1.403(11) C32 O5 1.342(12) O5 C33 1.443(9) C33 C34 1.4 25(12) C31' C32' 1.459(11) C32' O5' 1.375(11) O5' C33' 1.421(12) C33' C34' 1.540(16) Symmetry transformations used to generate equivalent atoms: Table A 21 Bond angles [] for 4 Bond Angles Bond Angles O4 Cr1 O1 116.73(9) O3 Cr1 O1 120.18(7) O3 Cr1 O2 113.13(7) O1 Cr1 O2 125.50(7) O3 Cr1 C1 98.90(8) O1 Cr1 C1 90.92(8) O2 Cr1 C1 91.51(8) O3 Cr1 O4 89.54(7) O1 Cr1 O4 84.70(7) O2 Cr1 O4 85.20(6) C1 Cr1 O4 171.55(7) C12 O1 Cr1 130.97(15) C22 O2 Cr1 126.29(14) Cr1#1 O3 Cr1 158.69(14) C30 O4 C27 109.45(19) C30 O4 Cr1 127.19(15) C27 O4 Cr1 123.27(14) C6 C1 C2 119.4(2) C6 C1 Cr1 121.40(17) C2 C1 Cr1 11 9.08(17) C3 C2 C1 119.1(2) C3 C2 C17 117.7(2) C1 C2 C17 123.1(2) C4 C3 C2 121.0(2) C5 C4 C3 120.5(2) C4 C5 C6 121.1(2) C5 C6 C1 119.0(2) C5 C6 C7 117.2(2) C1 C6 C7 123.7(2) C8 C7 C12 117.8(2) C8 C7 C6 121.0(2) C12 C7 C6 121.1(2) C9 C8 C7 121.2(3) C8 C9 C10 119.9(3) C9 C10 C11 122.5(3) C10 C11 C12 116.7(3) C10 C11 C13 122.0(2) C12 C11 C13 121.3(2) O1 C12 C7 120.4(2) O1 C12 C11 118.0(2) C7 C12 C11 121.6(2) C15 C13 C16 111.1(2) C15 C13 C14 107.5(2) C16 C13 C14 107.3(2) C15 C13 C11 110.0(2) C16 C13 C11 109.3(2) C14 C13 C11 111.6(2) C18 C17 C22 117.6(2)

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315 Table A 2 1 Continued Bond Angles Bond Angles C18 C17 C2 120.4(2) C22 C17 C2 121.9(2 ) C19 C18 C17 121.4(2) C18 C19 C20 120.3(2) C19 C20 C21 121.8(2) C20 C21 C22 116.9(2) C20 C21 C23 120.7(2) C22 C21 C23 122.3(2) O2 C22 C17 119.84(19) O2 C22 C21 118.3(2) C17 C22 C21 121.9(2) C25 C23 C21 110.0(2) C25 C23 C26 111.2(2) C21 C23 C26 109.8(2) C2 5 C23 C24 107.8(2) C21 C23 C24 111.62(19) C26 C23 C24 106.3(2) O4 C27 C28 105.8(2) C27 C28 C29 102.7(2) C28 C29 C30 103.2(2) O4 C30 C29 105.4(2) O5 C32 C31 109.7(11) C32 O5 C33 120.9(8) C34 C33 O5 115.1(8) O5' C32' C31' 144.4(11) C32' O5' C33' 113.1(9) O5' C33' C34' 102.9(11) Symmetry transformations used to generate equivalent atoms: Table A 22 Anisotropic displacement parameters ( 2 x 10 3 ) for 4 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ]. U 11 U 22 U 33 U 23 U 13 U 12 Cr1 23(1) 22(1) 17(1) 2(1) 6(1) 0(1) O1 31(1) 27(1) 27(1) 3(1) 13(1) 3(1) O2 28(1) 24(1) 17(1) 3(1) 8(1) 3(1) O3 26(1) 27(1) 23(1) 0 5(1) 0 O4 29(1) 35(1) 23(1) 5(1) 5(1) 4(1) C1 20(1) 24(1) 23(1) 1(1) 4(1) 1(1) C2 24(1) 24(1) 25(1) 1(1) 7(1) 0(1) C3 40(2) 30(1) 30(1) 5(1) 15(1) 1(1) C4 52(2) 26(1) 44(2) 9(1) 22(1) 2(1) C5 49(2) 19(1) 44(2) 1(1) 17(1) 1(1) C6 29(1) 25(1) 30(1) 1(1) 9(1) 0(1) C7 29 (1) 27(1) 35(1) 5(1) 8(1) 4(1) C8 44(2) 29(1) 48(2) 8(1) 11(1) 1(1) C9 57(2) 35(2) 48(2) 21(1) 10(2) 5(1) C10 46(2) 47(2) 34(2) 17(1) 10(1) 13(1) C11 27(1) 42(2) 30(1) 7(1) 5(1) 12(1) C12 25(1) 30(1) 28(1) 6(1) 4(1) 6(1) C13 34(1) 53(2) 28(1) 5(1) 12(1) 9(1) C14 45(2) 75(2) 36(2) 12(2) 16(1) 17(2) C15 45(2) 57(2) 29(2) 1(1) 14(1) 12(1) C16 35(2) 59(2) 39(2) 4(1) 15(1) 2(1) C17 25(1) 24(1) 19(1) 1(1) 5(1) 1(1) C18 37(1) 33(1) 25(1) 4(1) 13(1) 2(1) C19 45(2) 41( 2) 25(1) 6(1) 18(1) 2(1) C20 41(2) 31(1) 26(1) 9(1) 10(1) 1(1) C21 28(1) 25(1) 23(1) 1(1) 4(1) 1(1) C22 23(1) 25(1) 16(1) 1(1) 4(1) 1(1) C23 36(1) 22(1) 29(1) 6(1) 10(1) 5(1) C24 52(2) 28(2) 45(2) 11(1) 17(1) 10(1) C25 48(2) 28( 1) 36(2) 2(1) 13(1) 2(1) C26 35(2) 35(2) 43(2) 6(1) 12(1) 9(1) C27 34(1) 46(2) 37(2) 1(1) 13(1) 9(1)

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316 Table A 2 2 Continued U 11 U 22 U 33 U 23 U 13 U 12 C28 63(2) 52(2) 53(2) 5(2) 28(2) 17(2) C29 89(2) 43(2) 33(2) 10(1) 20(2) 3(2) C30 46( 2) 42(2) 29(1) 10(1) 3(1) 3(1) Figure A 168 X ray structure of 5 X ray experimental : Data were collected at 173 K on a Siemens SMART PLATFORM equipped with A CCD area detector and a graphite monochromator utilizing MoK radiation ( = 0.71073 ). Cell parameters were refined using up to 8192 reflections. A full sphere of data (1850 frames) was collected using the scan method (0.3 frame width). The first 50 frames were re measured at the end of data collection to m onitor instrument and crystal stability (maximum correction on I was < 1 %). Absorption corrections by integration were applied based on measured indexed crystal faces. The structure was solved by the Direct Methods in SHELXTL6, and refined using full ma trix least squares. The non H atoms were treated anisotropically,

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317 whereas the hydrogen atoms were calculated in ideal positions and were riding on their respective carbon atoms. In addition to the Cr complex, a dichloromethane solvent molecule was found and refined. A total of 655 parameters were refined in the final cycle of refinement using 9004 reflections with I > 2 (I) to yield R 1 and wR 2 of 3.25 % and 8.48 %, respectively. Refinement was done using F 2 SHELXTL6 (2000). Bruker AXS, Madison, Wisconsi n, USA. Table A 23 Crystal data and structure refinement for 5 Item Value Identification code orei1 Empirical formula C 63 H 59 Cl 2 Cr O 4 P 2 Formula weight 1064.94 Temperature 173(2) K Wavelength 0.71073 Crystal system Mon oclinic Space group P2(1)/n Unit cell dimensions a = = 20.0532(14) = 90. b = 11.8927(8) = 112.310(1). c = 23.8911(17) = 90. Volume 5271.2(6) 3 Z 4 Density (calculated) 1.342 Mg/m 3 Absorption coefficient 0.429 mm 1 F(000) 2228 Crystal size 0.32 x 0.21 x 0.11 mm 3 Theta range for data collection 1.13 to 25.97 Index ranges Reflections collected 33198 Independent reflections 10292 [R(int) = 0.0249] Completeness to theta = 27.50 99.5 % Absorption correction None Max. and min. transmission 0.9544 and 0.8751 Refinement method Full mat rix least squares on F 2 Data / restraints / parameters 10292 / 0 / 655 Goodness of fit on F 2 1.029 Final R indices [I>2sigma(I)] R1 = 0.0325, wR2 = 0.0848 [9004] R indices (all data) R1 = 0.0383, wR2 = 0.0887 Largest diff. peak and hole 0.438 and 0.439 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants.

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318 Table A 24 Atomic coordinates ( x 10 4 ) and eq uivalent isotropic displacement parameters ( 2 x 10 3 ) for 5 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) Cr1 4987(1) 4834(1) 2215(1) 12(1) P1 4353(1) 6479(1) 3054(1) 14(1) P2 6226(1) 3809(1) 1654(1) 13(1) Cl1 931(1) 3063(1) 64(1) 40(1) Cl2 309(1) 4276(1) 788(1) 47(1) O1 5542(1) 4307(1) 3018(1) 14(1) O2 4463(1) 5484(1) 1429(1) 14(1) O3 4434(1) 5820(1) 2548(1) 17(1) O4 5768(1) 4396(1) 1937(1) 16(1) C1 4362(1) 3489(1) 2043(1) 15(1) C2 4630(1) 2462(1) 2342(1 ) 16(1) C3 4171(1) 1522(2) 2192(1) 21(1) C4 3495(1) 1580(2) 1733(1) 25(1) C5 3244(1) 2582(2) 1429(1) 22(1) C6 3658(1) 3568(1) 1595(1) 16(1) C7 5381(1) 2330(1) 2805(1) 16(1) C8 5794(1) 3262(1) 3136(1) 14(1) C9 6477(1) 3076(1) 3618(1) 16(1) C10 6741(1) 1981( 2) 3729(1) 18(1) C11 6359(1) 1075(1) 3384(1) 19(1) C12 5691(1) 1254(1) 2930(1) 18(1) C13 6910(1) 4070(1) 3997(1) 18(1) C14 6463(1) 4707(2) 4292(1) 20(1) C15 7132(1) 4885(2) 3596(1) 21(1) C16 7608(1) 3668(2) 4510(1) 26(1) C17 3330(1) 4658(1) 1312(1) 16(1) C 18 3748(1) 5587(1) 1251(1) 15(1) C19 3400(1) 6618(1) 992(1) 17(1) C20 2650(1) 6676(2) 804(1) 20(1) C21 2242(1) 5772(2) 861(1) 22(1) C22 2579(1) 4781(2) 1115(1) 19(1) C23 3830(1) 7645(2) 927(1) 19(1) C24 4204(1) 7365(2) 488(1) 24(1) C25 3345(1) 8675(2) 668( 1) 31(1) C26 4396(1) 8005(2) 1545(1) 25(1) C27 4092(1) 5625(1) 3558(1) 16(1) C28 4423(1) 4579(2) 3736(1) 21(1) C29 4246(1) 3929(2) 4146(1) 26(1) C30 3744(1) 4313(2) 4369(1) 24(1) C31 3408(1) 5343(2) 4186(1) 22(1) C32 3581(1) 6004(2) 3783(1) 19(1) C33 3661( 1) 7520(1) 2763(1) 17(1) C34 3002(1) 7165(2) 2327(1) 23(1) C35 2427(1) 7908(2) 2127(1) 32(1) C36 2510(1) 8997(2) 2352(1) 35(1) C37 3163(1) 9361(2) 2766(1) 29(1) C38 3744(1) 8619(2) 2981(1) 23(1) C39 5184(1) 7157(1) 3512(1) 16(1) C40 5317(1) 7462(2) 4108(1) 23(1) C41 5966(1) 7967(2) 4456(1) 26(1) C42 6488(1) 8144(2) 4218(1) 27(1)

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319 Table A 2 4 Continued. Atom X Y Z U(eq) C43 6359(1) 7838(2) 3623(1) 26(1) C44 5705(1) 7355(2) 3269(1) 21(1) C45 5825(1) 2501(1) 1308(1) 16(1) C46 6224(1) 1629(2) 1199(1) 21(1) C47 5878(1) 664(2) 902(1) 26(1) C48 5135(1) 568(2) 717(1) 27(1) C49 4734(1) 1438(2) 818(1) 27(1) C50 5076(1) 2410(2) 1110(1) 21(1) C51 7125(1) 3515(1) 2188(1) 14(1) C52 7686(1) 4276(1) 2275(1) 17(1) C53 8368(1) 4071(2) 2714(1) 21(1) C54 8490(1) 3114(2) 3066(1 ) 22(1) C55 7930(1) 2367(2) 2994(1) 24(1) C56 7249(1) 2563(2) 2557(1) 19(1) C57 6296(1) 4668(1) 1056(1) 15(1) C58 5788(1) 5514(2) 821(1) 21(1) C59 5790(1) 6148(2) 331(1) 26(1) C60 6293(1) 5932(2) 76(1) 20(1) C61 6800(1) 5088(2) 308(1) 19(1) C62 6802(1) 445 5(2) 796(1) 18(1) C63 581(1) 3840(2) 612(1) 47(1) Table A 25 Bond lengths [] for 5 Bond Length Bond Length Cr1 O1 1.9211(11) Cr1 O2 1.9312(11) Cr1 C1 1.9761(17) Cr1 O3 1.9771(12) Cr1 O4 1.9896(11) P1 O3 1.5007(12) P1 C33 1.7915(17) P1 C27 1.7986(17) P1 C39 1.7997(17) P2 O4 1.5029(12) P2 C45 1.8007(17) P2 C57 1.8040(16) P2 C51 1.8047(16 ) Cl1 C63 1.759(2) Cl2 C63 1.750(2) O1 C8 1.330(2) O2 C18 1.3384(19) C1 C2 1.413(2) C1 C6 1.415(2) C2 C3 1.406(2) C2 C7 1.501(2) C3 C4 1.384(3) C4 C5 1.387(3) C5 C6 1.403(2) C6 C17 1.495(2) C7 C12 1.403(2) C7 C8 1.429(2) C8 C9 1.432(2) C9 C1 0 1.393(2) C9 C13 1.542(2) C10 C11 1.395(2) C11 C12 1.383(2) C13 C14 1.533(2) C13 C15 1.544(2) C13 C16 1.545(2) C17 C22 1.403(2) C17 C18 1.427(2) C18 C19 1.431(2) C19 C20 1.398(2) C19 C23 1.538(2) C20 C21 1.389(3) C21 C22 1.380(3) C23 C25 1. 540(2) C23 C24 1.540(2) C23 C26 1.542(2) C27 C28 1.398(2) C27 C32 1.399(2) C28 C29 1.394(3) C29 C30 1.383(3) C30 C31 1.387(3) C31 C32 1.387(2) C33 C38 1.393(2) C33 C34 1.402(2) C34 C35 1.385(3) C35 C36 1.389(3) C36 C37 1.377(3) C37 C38 1.395( 3) C39 C40 1.393(2)

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320 Table A 2 5 Continued Bond Length Bond Length C39 C44 1.396(2) C40 C41 1.386(3) C41 C42 1.384(3) C42 C4 3 1.393(3) C43 C44 1.386(3) C45 C46 1.394(2) C45 C50 1.396(2) C46 C47 1.388(3) C47 C48 1.389(3) C48 C49 1.386(3) C49 C50 1.389(3) C51 C56 1.397(2) C51 C52 1.398(2) C52 C53 1.392(2) C53 C54 1.382(3) C54 C55 1.389(3) C55 C56 1.388(2) C57 C58 1 .389(2) C57 C62 1.399(2) C58 C59 1.394(2) C59 C60 1.386(3) C60 C61 1.385(2) C61 C62 1.387(2) Symmetry transformations used to generate equivalent atoms: Table A 26 Bond angles [] for 5 Bond Angle Bond Angle O1 Cr1 O2 175.28(5) O1 Cr1 C1 91.46(6) O2 Cr1 C1 93.07(6) O1 Cr1 O3 89.59(5) O2 Cr1 O3 88.40(5) C1 Cr1 O3 98.96(6) O1 Cr1 O4 90.97(5) O2 Cr1 O4 89.24(5) C1 Cr1 O4 103.62(6) O3 Cr1 O4 157.38(5) O3 P1 C33 110.65(7) O3 P1 C27 113.16(7) C33 P1 C27 105.68(8) O3 P1 C39 111.47(7) C33 P1 C39 109.12(8) C27 P1 C39 106.47(8) O4 P2 C45 111.40(7) O4 P2 C57 109.74(7) C45 P2 C57 106.36(7) O4 P2 C51 112.84 (7) C45 P2 C51 108.03(8) C57 P2 C51 108.22(8) C8 O1 Cr1 123.01(10) C18 O2 Cr1 117.9(1) P1 O3 Cr1 151.94(7) P2 O4 Cr1 164.78(8) C2 C1 C6 121.22(15) C2 C1 Cr1 120.29(12) C6 C1 Cr1 118.43(12) C3 C2 C1 118.14(15) C3 C2 C7 118.74(15) C1 C2 C7 123.12(15) C4 C3 C 2 120.83(16) C3 C4 C5 120.57(16) C4 C5 C6 120.77(16) C5 C6 C1 118.15(15) C5 C6 C17 119.06(14) C1 C6 C17 122.75(15) C12 C7 C8 118.25(15) C12 C7 C2 119.44(15) C8 C7 C2 122.30(15) O1 C8 C7 120.97(14) O1 C8 C9 118.97(14) C7 C8 C9 120.01(15) C10 C9 C8 118.41(15 ) C10 C9 C13 121.10(15) C8 C9 C13 120.49(14) C9 C10 C11 121.73(15) C12 C11 C10 119.67(16) C11 C12 C7 121.70(16) C14 C13 C9 110.61(14) C14 C13 C15 109.42(14) C9 C13 C15 110.30(13) C14 C13 C16 107.49(14) C9 C13 C16 111.57(14) C15 C13 C16 107.34(14) C22 C17 C 18 118.78(15) C22 C17 C6 118.27(15) C18 C17 C6 122.93(14) O2 C18 C17 119.81(14) O2 C18 C19 120.25(15) C17 C18 C19 119.94(14) C20 C19 C18 118.01(15) C20 C19 C23 120.37(15) C18 C19 C23 121.62(14) C21 C20 C19 122.17(16) C22 C21 C20 119.67(16) C21 C22 C17 121. 43(16) C19 C23 C25 112.21(14) C19 C23 C24 109.55(14) C25 C23 C24 107.19(15) C19 C23 C26 111.13(14) C25 C23 C26 106.67(15) C24 C23 C26 109.97(15)

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321 Table A 2 6 Continued Bond Angle Bond Angle C28 C27 C32 120.18(16) C28 C27 P1 118.69(13) C32 C27 P1 121.11(13) C29 C28 C27 119.23(16) C30 C29 C28 120.27(17) C29 C30 C31 120.56(17) C32 C31 C30 119.93(16) C31 C32 C27 119.81(16) C38 C33 C34 120.35(16) C38 C33 P1 122.60(13) C34 C33 P1 116.92(13) C35 C34 C33 119.36(18) C34 C35 C36 120.02(19) C37 C36 C35 120.81(18) C36 C37 C38 120.00(18) C33 C38 C37 119.42(18) C40 C39 C44 119.84(16) C40 C39 P1 120.85(13) C44 C39 P1 119.29(13) C41 C40 C39 119.90( 17) C42 C41 C40 120.21(17) C41 C42 C43 120.18(17) C44 C43 C42 119.86(17) C43 C44 C39 119.98(16) C46 C45 C50 119.90(16) C46 C45 P2 122.69(13) C50 C45 P2 117.27(13) C47 C46 C45 119.96(17) C46 C47 C48 119.85(18) C49 C48 C47 120.49(17) C48 C49 C50 119.92(17) C 49 C50 C45 119.87(17) C56 C51 C52 119.43(15) C56 C51 P2 119.62(13) C52 C51 P2 120.74(13) C53 C52 C51 120.16(16) C54 C53 C52 120.02(16) C53 C54 C55 120.15(16) C56 C55 C54 120.28(17) C55 C56 C51 119.93(16) C58 C57 C62 119.68(15) C58 C57 P2 117.67(13) C62 C57 P2 122.46(13) C57 C58 C59 119.76(16) C60 C59 C58 120.17(17) C61 C60 C59 120.31(16) C60 C61 C62 119.81(16) C61 C62 C57 120.27(16) Cl2 C63 Cl1 113.04(12) Symmetry transformations used to generate equivalent atoms: Table A 27 Anisotropic displacement parameters ( 2 x 10 3 ) for 5 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 W1 9(1) 13(1) 11(1) 1(1) 0(1) 0(1) Cr1 11(1) 12(1) 12(1) 0(1) 4( 1) 1(1) P1 13(1) 14(1) 13(1) 1(1) 5(1) 2(1) P2 12(1) 13(1) 13(1) 1(1) 5(1) 1(1) Cl1 36(1) 49(1) 33(1) 3(1) 11(1) 2(1) Cl2 41(1) 42(1) 64(1) 18(1) 27(1) 14(1) O1 16(1) 13(1) 14(1) 0(1) 5(1) 2(1) O2 11(1) 17(1) 15(1) 3(1) 5(1) 1(1) O3 17( 1) 18(1) 16(1) 1(1) 6(1) 3(1) O4 15(1) 18(1) 16(1) 1(1) 8(1) 2(1) C1 16(1) 16(1) 14(1) 2(1) 8(1) 1(1) C2 18(1) 16(1) 16(1) 1(1) 8(1) 1(1) C3 22(1) 15(1) 26(1) 3(1) 8(1) 2(1) C4 22(1) 19(1) 31(1) 2(1) 7(1) 8(1) C5 16(1) 23(1) 22(1 ) 2(1) 3(1) 5(1) C6 16(1) 18(1) 15(1) 1(1) 7(1) 2(1) C7 18(1) 17(1) 16(1) 2(1) 9(1) 1(1) C8 15(1) 15(1) 14(1) 2(1) 8(1) 2(1) C9 17(1) 17(1) 15(1) 2(1) 8(1) 1(1) C10 17(1) 21(1) 18(1) 4(1) 7(1) 4(1) C11 23(1) 14(1) 23(1) 5(1) 13(1) 6 (1)

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322 Table A 2 7 Continued. U 11 U 22 U 33 U 23 U 13 U 12 C12 22(1) 15(1) 20(1) 0(1) 10(1) 2(1) C13 17(1) 18(1) 16(1) 0(1) 3(1) 2(1) C14 22(1) 22(1) 16(1) 2(1) 6(1) 0(1) C15 17(1) 21(1) 23(1) 2(1) 7(1) 2(1) C16 22(1) 23(1) 23(1) 1(1) 1(1) 3(1) C17 16(1) 20(1) 12(1) 1(1) 5(1) 2(1) C18 13(1) 20(1) 11(1) 1(1) 4(1) 1(1) C19 16(1) 20(1) 13(1) 0(1) 4(1) 1(1) C20 17(1) 23(1) 18(1) 4(1) 4(1) 5(1) C21 12(1) 33(1) 19(1) 4(1) 3(1) 2(1) C22 15(1) 25(1) 17(1) 1(1) 4(1) 4(1) C23 16( 1) 17(1) 21(1) 3(1) 5(1) 2(1) C24 31(1) 20(1) 25(1) 6(1) 15(1) 0(1) C25 24(1) 20(1) 45(1) 10(1) 9(1) 4(1) C26 26(1) 24(1) 24(1) 0(1) 7(1) 6(1) C27 13(1) 18(1) 14(1) 1(1) 3(1) 3(1) C28 19(1) 22(1) 24(1) 2(1) 10(1) 3(1) C29 28(1) 20(1) 31(1) 7(1) 13(1) 4(1) C30 27(1) 26(1) 22(1) 3(1) 11(1) 4(1) C31 19(1) 28(1) 19(1) 2(1) 9(1) 1(1) C32 17(1) 20(1) 18(1) 1(1) 5(1) 1(1) C33 18(1) 18(1) 16(1) 4(1) 9(1) 4(1) C34 22(1) 24(1) 21(1) 2(1) 6(1) 3(1) C35 22(1) 40(1) 27(1) 5(1 ) 1(1) 11(1) C36 35(1) 37(1) 31(1) 10(1) 11(1) 23(1) C37 40(1) 20(1) 33(1) 2(1) 19(1) 12(1) C38 27(1) 20(1) 23(1) 0(1) 12(1) 4(1) C39 15(1) 15(1) 18(1) 0(1) 4(1) 1(1) C40 20(1) 28(1) 20(1) 4(1) 9(1) 3(1) C41 28(1) 30(1) 18(1) 5(1) 5(1) 6(1) C42 24(1) 26(1) 25(1) 0(1) 3(1) 10(1) C43 23(1) 30(1) 27(1) 2(1) 11(1) 8(1) C44 23(1) 21(1) 19(1) 1(1) 9(1) 2(1) C45 18(1) 15(1) 13(1) 2(1) 6(1) 1(1) C46 21(1) 19(1) 23(1) 1(1) 6(1) 1(1) C47 34(1) 16(1) 25(1) 2(1) 10(1) 3(1) C48 37(1) 21(1) 21(1) 3(1) 9(1) 12(1) C49 24(1) 35(1) 22(1) 6(1) 10(1) 11(1) C50 19(1) 27(1) 17(1) 3(1) 8(1) 2(1) C51 14(1) 16(1) 14(1) 1(1) 6(1) 3(1) C52 20(1) 17(1) 17(1) 0(1) 8(1) 0(1) C53 16(1) 26(1) 20(1) 3(1) 7(1) 4(1) C54 14(1) 27(1) 22(1) 0(1) 4(1) 4(1) C55 23(1) 20(1) 24(1) 6(1) 5(1) 3(1) C56 18(1) 17(1) 21(1) 2(1) 6(1) 1(1) C57 16(1) 14(1) 13(1) 1(1) 4(1) 2(1) C58 21(1) 24(1) 22(1) 5(1) 12(1) 6(1) C59 28(1) 25(1) 26(1) 10(1) 13(1) 10(1) C60 24(1) 2 1(1) 16(1) 4(1) 8(1) 2(1) C61 19(1) 23(1) 18(1) 2(1) 10(1) 1(1) C62 18(1) 19(1) 18(1) 1(1) 7(1) 3(1) C63 41(1) 50(2) 65(2) 27(1) 36(1) 13(1)

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323 Figure A 169 Molecular Structure of 6 X ray experimental : Data were collected at 173 K on a Siemens SMART PLATFORM equipped with A CCD area detector and a graphite monochromator utilizing MoK radiation ( = 0.71073 ). Cell parameters were refined using up to 8192 reflections. A full sphere of data (1850 frames) wa s collected using the scan method (0.3 frame width). The first 50 frames were re measured at the end of data collection to monitor instrument and crystal stability (maximum correction on I was < 1 %). Absorption corrections by integration were applied based on measured indexed crystal faces.

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324 The structure was solved by the Direct Methods in SHELXTL6, and refined using full matrix least squares. The non H atoms were treated anisotropically, whereas the hydrogen atoms were calculated in ideal positions and were riding on their respective carbon atoms The asymmetric unit consists of the Cr complex and two toluene solvent molecules. A total of 593 parameters were refined in the final cycle of refinement using 7354 reflections with I > 2 (I) to yield R 1 and wR 2 of 3.60 % and 7.60 %, respectively. Refinement was done using F 2 SHELXTL6 (2000). Bruker AXS, Madison, Wisconsin, USA. Table A 28 Crystal data and structure refinement for 6 Item Value Identifica tion code orei20 Empirical formula C 59 H 60 CrO 3 P Formula weight 900.04 Temperature 100(2) K Wavelength 0.71073 Crystal system Triclinic Space group P 1 Unit cell dimensions a = 11.0808(10) = 90 . b = 16.9424(15) = 101.572(2) . c = 25.884(2) = 90 . Volume 4760.6(7) 3 Z 4 Density (calculated) 1.256 Mg/m 3 Absorption coefficient 0.320 mm 1 F(000) 1908 Crystal size 0.26 x 0.12 x 0.06 mm 3 Theta range for data collection 1.45 to 27.50 . Index ranges Reflections coll ected 58088 Independent reflections 10940 [R(int) = 0.0625 ] Completeness to theta = 25.48 100.0 % Absorption correction Numerical Max. and min. transmission 0.9805 and 0.9227 Refinement method Full matrix least squares on F 2 Data / restraints / parameter s 10940 / 0 / 593 Goodness of fit on F 2 0.911 Final R indices [I>2sigma(I)] R1 = 0.0360 wR2 = 0.0760 [7354 ] R indices (all data) R1 = 0.0674 wR2 = 0.0828 Largest diff. peak and hole 0.482 and 0.510 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants.

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325 Table A 29 Atomic coordinates ( x 10 4 ) and equi valent isotropic displacement parameters ( 2 x 10 3 ) for 6 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) Cr1 218(1) 6781(1) 1991(1) 12(1) P1 2582(1) 6690(1) 2818(1) 12(1) O1 835(1) 6998(1) 1532(1) 13(1) O2 493(1) 6242(1) 2582(1) 13(1) O4 1255(1) 7424(1) 1869(1) 16(1) C1 508(2) 7011(1) 1000(1) 14(1) C2 867(2) 7658(1) 717(1) 16(1) C3 546(2) 7620(1) 169(1) 19(1) C4 112(2) 6993(1) 94(1) 22(1) C5 470(2) 6376(1) 189(1) 20(1) C6 152(2) 6368(1) 739(1) 15(1) C 7 542(2) 5706(1) 1041(1) 16(1) C8 687(2) 4959(1) 801(1) 20(1) C9 1150(2) 4332(1) 1040(1) 23(1) C10 1551(2) 4445(1) 1506(1) 21(1) C11 1434(2) 5185(1) 1756(1) 16(1) C12 833(2) 5808(1) 1545(1) 14(1) C13 2000(2) 5284(1) 2224(1) 15(1) C14 3059(2) 4855(1 ) 2266(1) 18(1) C15 3589(2) 4941(1) 2699(1) 19(1) C16 3073(2) 5456(1) 3098(1) 16(1) C17 2034(2) 5908(1) 3079(1) 15(1) C18 1506(2) 5817(1) 2622(1) 13(1) C19 1551(2) 8373(1) 997(1) 17(1) C20 768(2) 8777(1) 1351(1) 19(1) C21 2798(2) 8108(1) 1325(1) 22(1) C22 1823(2) 9002(1) 605(1) 27(1) C23 1469(2) 6462(1) 3529(1) 16(1) C24 2219(2) 6487(1) 3968(1) 24(1) C25 166(2) 6168(1) 3775(1) 20(1) C26 1430(2) 7313(1) 3324(1) 18(1) C27 1281(2) 7271(1) 2557(1) 13(1) C28 2276(2) 5650(1) 2722(1) 14(1) C29 1961(2) 5355 (1) 2208(1) 16(1) C30 1635(2) 4572(1) 2124(1) 19(1) C31 1618(2) 4075(1) 2550(1) 21(1) C32 1935(2) 4362(1) 3061(1) 19(1) C33 2262(2) 5147(1) 3149(1) 17(1) C34 3116(2) 6852(1) 3519(1) 13(1) C35 2454(2) 7311(1) 3810(1) 16(1) C36 2895(2) 7422(1) 4348(1) 18(1) C37 3988(2) 7078(1) 4593(1) 19(1) C38 4660(2) 6622(1) 4305(1) 19(1) C39 4226(2) 6512(1) 3771(1) 18(1) C40 3880(2) 6962(1) 2531(1) 15(1) C41 4371(2) 7716(1) 2650(1) 19(1) C42 5376(2) 7964(1) 2450(1) 24(1) C43 5894(2) 7463(1) 2127(1) 23(1) C44 5420(2) 6721(1 ) 2015(1) 23(1) C45 4418(2) 6460(1) 2216(1) 18(1) C46 3300(2) 6126(1) 563(1) 52(1)

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326 Table A 29 Continued. Atom X Y Z U(eq) C47 3689(2) 5294(1) 711(1) 28(1) C48 2891(2) 4777(1) 878(1) 34(1) C49 3246(3) 4007(2) 1012(1) 50(1) C50 4400(3) 3744(1) 980(1) 47(1 ) C51 5205(2) 4257(2) 816(1) 44(1) C52 4857(2) 5022(1) 683(1) 40(1) C53 6617(2) 7217(1) 720(1) 34(1) C54 6686(2) 8096(1) 635(1) 22(1) C55 5813(2) 8608(1) 767(1) 25(1) C56 5846(2) 9409(1) 661(1) 30(1) C57 6767(2) 9716(1) 433(1) 31(1) C58 7651(2) 9217(1) 313 (1) 31(1) C59 7610(2) 8416(1) 409(1) 26(1) Table A 30 Bond lengths [] for 6 Bond Length Bond Length Cr1 O4 1.5699(11) Cr1 O2 1.8576(11) Cr1 O1 1.8615(11) Cr1 C12 2.0495(17) Cr1 C27 2.1483(17) P1 C27 1.7650(17) P1 C28 1.8007(18) P1 C40 1.8060(17) P1 C34 1.8144(17) O1 C1 1.3535(19) O2 C18 1.3551(19) C1 C6 1.406(2) C1 C2 1.419(2) C2 C3 1. 392(2) C2 C19 1.533(2) C3 C4 1.388(3) C4 C5 1.379(3) C5 C6 1.398(2) C6 C7 1.481(2) C7 C8 1.405(2) C7 C12 1.415(2) C8 C9 1.378(2) C9 C10 1.380(2) C10 C11 1.405(2) C11 C12 1.415(2) C11 C13 1.481(2) C13 C18 1.397(2) C13 C14 1.402(2) C14 C15 1.3 74(2) C15 C16 1.386(2) C16 C17 1.392(2) C17 C18 1.428(2) C17 C23 1.529(2) C19 C21 1.536(2) C19 C22 1.541(2) C19 C20 1.542(2) C23 C24 1.536(2) C23 C25 1.539(2) C23 C26 1.541(2) C27 H27B 0.938(18) C27 H27A 0.933(19) C28 C33 1.397(2) C28 C29 1.3 99(2) C29 C30 1.381(2) C30 C31 1.391(2) C31 C32 1.385(2) C32 C33 1.385(2) C34 C35 1.390(2) C34 C39 1.396(2) C35 C36 1.392(2) C36 C37 1.379(2) C37 C38 1.388(2) C38 C39 1.382(2) C40 C45 1.394(2) C40 C41 1.399(2) C41 C42 1.383(2) C42 C43 1.392(3 ) C43 C44 1.371(3) C44 C45 1.390(2) C46 C47 1.500(3) C47 C48 1.375(3) C47 C52 1.390(3) C48 C49 1.386(3) C49 C50 1.373(3) C50 C51 1.373(3) C51 C52 1.375(3) C53 C54 1.509(3) C54 C59 1.386(3) C54 C55 1.393(3) C55 C56 1.386(3) Symmetry transforma tions used to generate equivalent atoms:

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327 Table A 31 Bond angles [] for 6 Bond Angle Bond Angle O4 Cr 1 O2 105.86(6) O4 Cr1 O1 105.10(6) O2 Cr1 O1 148.23(5) O4 Cr1 C12 107.32(6) O2 Cr1 C12 88.71(6) O1 Cr1 C12 88.82(6) O4 Cr1 C27 107.62(6) O2 Cr1 C27 82.05(6) O1 Cr1 C27 82.01(6) C12 Cr1 C27 145.05(7) C27 P1 C28 112.13(8) C27 P1 C40 110.91(8) C28 P1 C40 109. 69(8) C27 P1 C34 112.10(8) C28 P1 C34 107.45(8) C40 P1 C34 104.20(8) C1 O1 Cr1 125.4(1) C18 O2 Cr1 126.87(10) O1 C1 C6 118.91(15) O1 C1 C2 119.43(15) C6 C1 C2 121.63(15) C3 C2 C1 116.69(16) C3 C2 C19 121.25(16) C1 C2 C19 122.05(15) C4 C3 C2 122.45(17) C5 C 4 C3 119.86(17) C4 C5 C6 120.59(17) C5 C6 C1 118.74(16) C5 C6 C7 120.37(16) C1 C6 C7 120.85(15) C8 C7 C12 119.45(16) C8 C7 C6 117.92(15) C12 C7 C6 122.54(16) C9 C8 C7 120.98(17) C8 C9 C10 119.95(17) C9 C10 C11 120.70(17) C10 C11 C12 119.67(16) C10 C11 C13 117.56(16) C12 C11 C13 122.72(15) C7 C12 C11 118.42(15) C7 C12 Cr1 120.44(12) C11 C12 Cr1 120.76(12) C18 C13 C14 119.17(15) C18 C13 C11 120.64(15) C14 C13 C11 120.18(16) C15 C14 C13 120.64(16) C14 C15 C16 119.69(16) C15 C16 C17 122.69(16) C16 C17 C18 116.7 0(16) C16 C17 C23 121.64(15) C18 C17 C23 121.64(15) O2 C18 C13 119.61(15) O2 C18 C17 119.31(15) C13 C18 C17 121.07(15) C2 C19 C21 109.56(14) C2 C19 C22 112.21(15) C21 C19 C22 107.03(14) C2 C19 C20 110.35(14) C21 C19 C20 110.64(14) C22 C19 C20 106.98(15) C1 7 C23 C24 112.44(14) C17 C23 C25 108.86(14) C24 C23 C25 107.75(14) C17 C23 C26 110.33(14) C24 C23 C26 106.58(14) C25 C23 C26 110.84(14) P1 C27 Cr1 120.32(9) P1 C27 H27B 109.5(11) Cr1 C27 H27B 101.8(11) P1 C27 H27A 108.2(11) Cr1 C27 H27A 107.2(11) H27B C27 H27A 109.5(16) C33 C28 C29 119.55(16) C33 C28 P1 121.33(13) C29 C28 P1 118.97(13) C30 C29 C28 120.07(16) C29 C30 C31 120.09(17) C32 C31 C30 120.17(17) C31 C32 C33 120.11(17) C32 C33 C28 120.00(16) C35 C34 C39 119.30(15) C35 C34 P1 121.67(13) C39 C34 P1 119 .03(13) C34 C35 C36 120.02(16) C37 C36 C35 120.12(17) C36 C37 C38 120.30(16) C39 C38 C37 119.72(16) C38 C39 C34 120.53(16) C45 C40 C41 119.49(16) C45 C40 P1 123.71(14) C41 C40 P1 116.78(13) C42 C41 C40 120.15(17) C41 C42 C43 119.94(18) C44 C43 C42 119.98(1 7) C43 C44 C45 120.86(17) C44 C45 C40 119.56(17) C48 C47 C52 117.9(2) C48 C47 C46 120.6(2) C52 C47 C46 121.5(2) C47 C48 C49 120.7(2) C50 C49 C48 120.7(2) C49 C50 C51 119.0(2) C51 C52 C47 121.2(2) C59 C54 C55 117.87(19) C59 C54 C53 120.73(18)

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328 Table A 3 1 Continued Bond Angle Bond Angle C55 C54 C53 121.38(18) C56 C55 C54 120.98(18) C57 C56 C55 120.30(19) C58 C57 C56 119.1(2) C57 C58 C 59 120.75(19) C58 C59 C54 120.92(19) Symmetry transformations used to generate equivalent atoms: Table A 32 Anisotropic displacement parameters ( 2 x 10 3 ) for 6 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 Cr1 12(1) 12(1) 11(1) 0(1) 3(1) 0(1) P1 13(1) 13(1) 11(1) 0(1) 2(1) 0(1) O1 15(1) 16(1) 10(1) 0(1) 3(1) 1(1) O2 14(1) 14(1) 11(1) 0(1) 4(1) 4(1) O4 15(1) 15(1) 16(1) 2(1) 2 (1) 1(1) C1 13(1) 18(1) 12(1) 0(1) 4(1) 4(1) C2 15(1) 18(1) 14(1) 1(1) 6(1) 4(1) C3 21(1) 22(1) 16(1) 4(1) 8(1) 6(1) C4 26(1) 31(1) 10(1) 0(1) 5(1) 8(1) C5 22(1) 23(1) 16(1) 6(1) 4(1) 2(1) C6 15(1) 18(1) 14(1) 2(1) 5(1) 2(1) C7 13(1) 18(1) 16(1) 4(1) 2(1) 0(1) C8 21(1) 22(1) 18(1) 7(1) 6(1) 1(1) C9 25(1) 16(1) 29(1) 9(1) 10(1) 4(1) C10 23(1) 16(1) 25(1) 4(1) 9(1) 6(1) C11 14(1) 16(1) 17(1) 2(1) 2(1) 0(1) C12 12(1) 14(1) 14(1) 3(1) 1(1) 1(1) C13 17(1) 13(1) 16 (1) 2(1) 5(1) 1(1) C14 21(1) 13(1) 20(1) 2(1) 3(1) 4(1) C15 18(1) 18(1) 22(1) 2(1) 6(1) 4(1) C16 17(1) 16(1) 17(1) 3(1) 7(1) 2(1) C17 16(1) 14(1) 14(1) 2(1) 2(1) 2(1) C18 14(1) 11(1) 14(1) 4(1) 3(1) 1(1) C19 20(1) 16(1) 17(1) 4(1) 6(1 ) 1(1) C20 23(1) 16(1) 20(1) 0(1) 6(1) 0(1) C21 19(1) 22(1) 24(1) 2(1) 5(1) 2(1) C22 34(1) 22(1) 25(1) 5(1) 10(1) 4(1) C23 18(1) 19(1) 11(1) 0(1) 5(1) 1(1) C24 28(1) 29(1) 16(1) 4(1) 10(1) 6(1) C25 21(1) 23(1) 15(1) 1(1) 1(1) 1(1) C26 23(1) 17(1) 16(1) 2(1) 6(1) 1(1) C27 14(1) 12(1) 13(1) 1(1) 4(1) 0(1) C28 12(1) 13(1) 16(1) 1(1) 3(1) 1(1) C29 18(1) 17(1) 13(1) 2(1) 2(1) 4(1) C30 23(1) 17(1) 16(1) 4(1) 2(1) 2(1) C31 24(1) 13(1) 26(1) 2(1) 5(1) 1(1) C32 22(1) 16(1) 20(1) 4(1) 6(1) 0(1) C33 17(1) 20(1) 15(1) 0(1) 3(1) 2(1) C34 14(1) 12(1) 14(1) 1(1) 3(1) 2(1) C35 15(1) 16(1) 16(1) 3(1) 2(1) 1(1) C36 22(1) 18(1) 15(1) 2(1) 5(1) 1(1) C37 22(1) 21(1) 12(1) 0(1) 0(1) 2(1) C38 15(1) 22(1) 19(1) 4(1) 0(1) 1(1)

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329 Table A 3 2 Continued. U 11 U 22 U 33 U 23 U 13 U 12 C39 17(1) 18(1) 18(1) 0(1) 4(1) 1(1) C40 13(1) 17(1) 14(1) 3(1) 2(1) 2(1) C41 16(1) 20(1) 21(1) 0(1) 5(1) 1(1) C42 17(1) 22(1) 30(1) 6(1) 2(1) 1(1) C43 14(1) 31(1) 26(1) 11( 1) 7(1) 3(1) C44 22(1) 27(1) 22(1) 6(1) 10(1) 8(1) C45 19(1) 18(1) 19(1) 2(1) 6(1) 3(1) C46 58(2) 36(2) 62(2) 10(1) 14(1) 11(1) C47 30(1) 25(1) 29(1) 0(1) 4(1) 2(1) C48 32(1) 38(1) 37(1) 2(1) 15(1) 1(1) C49 68(2) 37(2) 52(2) 3(1) 31(1) 10(1) C50 75(2) 29(1) 36(1) 4(1) 8(1) 16(1) C51 35(1) 46(2) 48(2) 5(1) 3(1) 13(1) C52 30(1) 38(1) 55(2) 1(1) 13(1) 0(1) C53 35(1) 35(1) 28(1) 2(1) 1(1) 0(1) C54 19(1) 32(1) 13(1) 2(1) 3(1) 1(1) C55 18(1) 40(1) 19(1) 8(1) 4(1) 6(1 ) C56 26(1) 37(1) 27(1) 12(1) 2(1) 4(1) C57 39(1) 30(1) 21(1) 2(1) 2(1) 4(1) C58 28(1) 47(2) 18(1) 1(1) 6(1) 10(1) C59 20(1) 41(1) 18(1) 5(1) 3(1) 3(1)

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330 Figure A 170 Molecular Structure of 12 X Ray e xperimental : X Ray Intensity data were collected at 100 K on a Bruker DUO diffractometer using MoK radiation ( = 0.71073 ) and an APEXII CCD area detector. Raw data frames were read by program SAINT 1 and integrated using 3D profiling algorithms. The r esulting data were reduced to produce hkl reflections and their intensities and estimated standard deviations. The data were corrected for Lorentz and polarization effects and numerical absorption corrections were applied based on indexed and measured fac es. The structure was solved and refined in SHELXTL6.1, using full matrix least squares refinement. The non H atoms were refined with anisotropic thermal parameters and all of the H atoms were calculated in idealized positions and refined riding on thei r parent atoms. The C28 unit is disordered and was refined in two parts

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331 refined to this value. In the final cycle of refinement, 7092 reflections (of which 5724 ar e observed with I > 2 (I)) were used to refine 412 parameters and the resulting R 1 wR 2 and S (goodness of fit) were 2.42 %, 4.73 % and 1.056 respectively. The refinement was carried out by minimizing the wR 2 function using F 2 rather than F values. R 1 is calculated to provide a reference to the conventional R value but its function is not minimized. SHELXTL6 (2008). Bruker AXS, Madison, Wisconsin, USA. Table A 33 Crystal data and structure refinement for 12 Item Value Identification code orei3 6 Empirical formula C29 H31 F12 N O3 W Formula weight 853.40 Temperature 100(2) K Wavelength 0.71073 Crystal system Monoclinic Space group P2 1 /n Unit cell dimensions a = 11.4139(18) = 90. b = 9.5278(15) = 97.389(3). c = 28.609(5) = 90. Volume 3085.4(8) 3 Z 4 Density (calculated) 1.837 Mg/m 3 Absorption coefficient 3.849 mm 1 F(000) 1672 Crystal size 0.42 x 0.10 x 0.02 mm 3 Theta range for data collection 1.85 to 27.50. In dex ranges Reflections collected 43295 Independent reflections 7092 [R(int) = 0.0459] Completeness to theta = 27.50 100.0 % Absorption correction Numerical Max. and min. transmission 0.9201 and 0.2954 Refinement method Full m atrix least squares on F 2 Data / restraints / parameters 7092 / 0 / 412 Goodness of fit on F 2 1.056 Final R indices [I>2sigma(I)] R1 = 0.0242, wR2 = 0.0473 [5724] R indices (all data) R1 = 0.0350, wR2 = 0.0496 Largest diff. peak and hole 1.537 and 0.767 e . 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants.

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332 Table A 34 Atomic coordinates ( x 10 4 ) and eq uivalent isotropic displacement parameters ( 2 x 10 3 ) for 12 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) W1 2542(1) 10022(1) 3572(1) 11(1) F1 169(2) 9337(2) 4292(1) 25(1) F2 986(1) 8840(2) 3594(1) 24(1 ) F3 989(1) 7324(2) 4146(1) 22(1) F4 145(2) 6522(2) 3193(1) 25(1) F5 330(2) 5315(2) 3824(1) 23(1) F6 1667(2) 5973(2) 3408(1) 24(1) F7 5320(2) 9786(2) 2600(1) 22(1) F8 5440(2) 11870(2) 2887(1) 20(1) F9 6908(1) 10462(2) 3030(1) 20(1) F10 5896(2) 12077(2) 3 826(1) 25(1) F11 6946(1) 10217(2) 3957(1) 21(1) F12 5303(2) 10409(2) 4241(1) 19(1) O1 1225(2) 8710(2) 3522(1) 13(1) O2 4023(2) 10487(2) 3342(1) 13(1) O3 1593(2) 11282(2) 3045(1) 18(1) N1 3447(2) 8401(2) 3889(1) 11(1) C1 874(2) 7769(3) 3846(1) 12(1) C2 1784 (2) 7498(3) 4282(1) 12(1) C3 2994(2) 7754(3) 4276(1) 11(1) C4 3782(2) 7388(3) 4674(1) 14(1) C5 3396(3) 6796(3) 5064(1) 15(1) C6 2201(3) 6538(3) 5077(1) 15(1) C7 1421(2) 6892(3) 4685(1) 14(1) C8 329(3) 8312(3) 3973(1) 17(1) C9 671(3) 6385(3) 3569(1) 17(1) C10 1781(3) 5899(4) 5507(1) 24(1) C11 5172(2) 10001(3) 3417(1) 12(1) C12 5214(2) 8391(3) 3468(1) 11(1) C13 4359(2) 7689(3) 3699(1) 12(1) C14 4446(2) 6221(3) 3734(1) 14(1) C15 5331(3) 5482(3) 3560(1) 17(1) C16 6184(2) 6156(3) 3339(1) 17(1) C17 6109(2) 7610( 3) 3301(1) 15(1) C18 5726(2) 10532(3) 2982(1) 16(1) C19 5836(2) 10677(3) 3866(1) 15(1) C20 7151(3) 5346(3) 3147(1) 25(1) C21 2363(2) 11017(3) 4074(1) 13(1) C22 2411(3) 11896(3) 4508(1) 16(1) C23 2936(3) 11016(4) 4933(1) 27(1) C24 1174(3) 12400(3) 4579(1) 2 3(1) C25 3202(3) 13175(3) 4454(1) 26(1) C26 890(3) 12526(3) 3135(1) 24(1) C27 347(3) 12141(4) 3193(2) 43(1) C28 1156(7) 10644(8) 2583(2) 29(2) C28' 1660(6) 11005(7) 2542(2) 22(1) C29 1877(3) 9493(4) 2466(1) 35(1)

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333 Table A 35 Bond angles [ ] for 12 Bond Angle Bond Angle C21 W1 O2 110.62(11) C21 W1 O1 103.76(10) O2 W1 O1 144.97(8) C21 W1 N1 98.87(11) O2 W1 N1 84.79(8) O1 W1 N1 83.51(9) C21 W1 O3 100.02(10) O2 W1 O3 90.97(8) O1 W1 O3 89.50(8) N1 W1 O3 160.94(8) C1 O1 W1 130.73(16) C11 O2 W1 136.15(16) C26 O3 C28' 114.4(3) C26 O3 C28 111.0(3) C28' O3 C28 27.1(3) C26 O3 W1 124.91(17) C28' O3 W1 120.6(3) C28 O3 W1 119.1(3) C13 N1 C3 117.0(2) C13 N1 W1 123.92(17) C3 N1 W1 117.86(17) O1 C1 C2 115.4(2) O1 C1 C9 104.3(2) C2 C1 C9 108.3(2) O1 C1 C8 106.4(2) C2 C1 C8 113.0(2) C9 C1 C8 109.0(2) C7 C2 C3 118.4(2) C7 C2 C1 119.8(2) C3 C2 C1 121.6(2) C4 C3 C2 118.6( 2) C4 C3 N1 118.8(2) C2 C3 N1 122.7(2) C5 C4 C3 121.5(3) C4 C5 C6 120.9(3) C7 C6 C5 117.8(2) C7 C6 C10 121.5(3) C5 C6 C10 120.7(3) C6 C7 C2 122.8(3) F1 C8 F2 107.0(2) F1 C8 F3 107.2(2) F2 C8 F3 106.3(2) F1 C8 C1 110.9(2) F2 C8 C1 110.9(2) F3 C8 C1 114.1(2) F4 C9 F6 106.7(2) F4 C9 F5 106.9(2) F6 C9 F5 106.4(2) F4 C9 C1 111.9(2) F6 C9 C1 110.5(2) F5 C9 C1 114.0(2) O2 C11 C12 111.5(2) O2 C11 C19 110.1(2) C12 C11 C19 109.3(2) O2 C11 C18 104.1(2) C12 C11 C18 112.9(2) C19 C11 C18 108.9(2) C17 C12 C13 119.1(2) C17 C12 C11 120.9(2) C13 C12 C11 120.0(2) C14 C13 N1 120.0(2) C14 C13 C12 117.2(2) N1 C13 C12 122.8(2) C15 C14 C13 122.2(3) C14 C15 C16 121.3(3) C15 C16 C17 117.3(3) C15 C16 C20 121.3(3) C17 C16 C20 121.4(3) C16 C17 C12 122.9(3) F8 C18 F7 106.9(2) F8 C18 F9 1 06.6(2) F7 C18 F9 107.3(2) F8 C18 C11 111.1(2) F7 C18 C11 110.4(2) F9 C18 C11 114.2(2) F12 C19 F11 107.5(2) F12 C19 F10 107.1(2) F11 C19 F10 106.6(2) F12 C19 C11 111.4(2) F11 C19 C11 112.2(2) F10 C19 C11 111.7(2) C22 C21 W1 171.2(2) C21 C22 C24 110.5(2) C2 1 C22 C23 108.8(2) C24 C22 C23 109.9(2) C21 C22 C25 108.7(2) C24 C22 C25 109.2(2) C23 C22 C25 109.8(3) O3 C26 C27 111.5(3) C29 C28 O3 112.6(5) O3 C28' C29 110.3(4) C28 C29 C28' 27.4(3) Symmetry transformations used to generate equivalent atoms:

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334 Table A 36 Bond lengths [ ] for 12 Bond Length Bond Length W1 C21 1.754(3) W1 O2 1.9419(18) W1 O1 1 .9462(18) W1 N1 2.008(2) W1 O3 2.1144(19) F1 C8 1.332(3) F2 C8 1.335(3) F3 C8 1.340(3) F4 C9 1.335(3) F5 C9 1.340(3) F6 C9 1.339(3) F7 C18 1.336(3) F8 C18 1.336(3) F9 C18 1.340(3) F10 C19 1.341(3) F11 C19 1.335(3) F12 C19 1.325(3) O1 C1 1.38 5(3) O2 C11 1.382(3) O3 C26 1.473(3) O3 C28' 1.474(6) O3 C28 1.481(7) N1 C13 1.409(3) N1 C3 1.422(3) C1 C2 1.538(4) C1 C9 1.540(4) C1 C8 1.554(4) C2 C7 1.399(4) C2 C3 1.405(4) C3 C4 1.401(4) C4 C5 1.371(4) C5 C6 1.391(4) C6 C7 1.383(4) C6 C1 0 1.505(4) C11 C12 1.541(4) C11 C19 1.544(4) C11 C18 1.551(4) C12 C17 1.397(4) C12 C13 1.414(4) C13 C14 1.406(4) C14 C15 1.375(4) C15 C16 1.384(4) C16 C17 1.392(4) C16 C20 1.507(4) C21 C22 1.494(4) C22 C24 1.530(4) C22 C23 1.534(4) C22 C25 1 .536(4) C26 C27 1.488(5) C28 C29 1.437(8) C28' C29 1.483(7) Symmetry transformations used to generate equivalent atoms: Table A 37 Anisotropic displacement parameters ( 2 x 10 3 ) for 12 The anisotropic displacement fact or exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 W1 10(1) 11(1) 12(1) 3(1) 2(1) 1(1) F1 22(1) 24(1) 31(1) 10(1) 8(1) 3(1) F2 13(1) 33(1) 27(1) 9(1) 1(1) 4(1) F3 14(1) 27(1) 27(1) 5(1) 8(1) 4(1) F4 26(1) 29(1) 18(1) 5(1) 6(1) 6(1) F5 31(1) 13(1) 26(1) 0(1) 4(1) 8(1) F6 22(1) 23(1) 27(1) 10(1) 9(1) 0(1) F7 31(1) 22(1) 12(1) 1(1) 4(1) 7(1) F8 26(1) 15(1) 21(1) 6(1) 6(1) 3(1) F9 14(1) 25(1) 24(1) 3(1) 9(1) 4(1) F10 42(1) 11(1) 21(1) 1(1) 3(1) 4(1) F11 14(1) 29(1) 20(1) 2(1) 2(1) 1(1) F12 22(1) 24(1) 11(1) 0(1) 4(1) 0(1) O1 10(1) 16(1) 12(1) 5(1) 0(1) 3(1) O2 8(1) 15(1) 17(1) 6(1) 4(1) 2(1) O3 18(1) 19(1) 15(1) 3(1) 0(1) 5(1) N1 12(1) 10(1) 12(1) 3 (1) 4(1) 2(1) C1 13(1) 13(1) 11(1) 0(1) 3(1) 2(1) C2 12(1) 12(1) 12(1) 2(1) 1(1) 0(1) C3 16(1) 7(1) 10(1) 1(1) 4(1) 1(1)

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335 Table A 3 7 Continued. U 11 U 22 U 33 U 23 U 13 U 12 C4 13(1) 14(1) 14(1) 2(1) 2(1) 0(1) C5 18(1) 14(1) 11(1) 0(1) 3(1) 1(1) C6 20(2) 16(1) 10(1) 0(1) 4(1) 2(1) C7 14(1) 13(1) 15(1) 1(1) 4(1) 2(1) C8 16(2) 18(1) 18(1) 2(1) 4(1) 2(1) C9 17(1) 17(1) 18(1) 2(1) 2(1) 3(1) C10 22(2) 32(2) 16(2) 7(1) 4(1) 5(1) C11 10(1) 14(1) 13(1) 1(1) 1(1) 1(1) C12 12(1) 12(1) 11(1) 1(1) 0(1) 1(1) C13 11(1) 13(1) 12(1) 0(1) 1(1) 0(1) C14 14(1) 15(1) 15(1) 2(1) 3(1) 1(1) C15 17(2) 12(1) 20(1) 2(1) 1(1) 3(1) C16 14(1) 17(1) 20(1) 3(1) 2(1) 2(1) C17 13(1) 16(1) 16(1) 1(1) 3(1) 2(1) C18 13(1) 17( 1) 17(1) 1(1) 2(1) 3(1) C19 16(1) 13(1) 15(1) 0(1) 1(1) 1(1) C20 21(2) 19(2) 35(2) 3(1) 10(1) 5(1) C21 12(1) 9(1) 18(1) 4(1) 4(1) 1(1) C22 17(2) 13(1) 18(1) 0(1) 3(1) 0(1) C23 38(2) 27(2) 14(1) 1(1) 2(1) 6(2) C24 23(2) 23(2) 24(2) 3(1) 8(1) 2(1) C25 28(2) 20(2) 30(2) 7(1) 10(1) 4(1) C26 24(2) 18(2) 29(2) 5(1) 0(1) 11(1) C27 22(2) 32(2) 74(3) 1(2) 7(2) 5(2) Figure A 171 Molecular Structure of 13

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336 X Ray experim ental : X Ray Intensity data were collected at 100 K on a Bruker DUO diffractometer using MoK radiation ( = 0.71073 ) and an APEXII CCD area detector. Raw data frames were read by program SAINT 1 and integrated using 3D profiling algorithms. The resulting data were reduced to produce hkl reflections and their intensities and estimated standar d deviations. The data were corrected for Lorentz and polarization effects and numerical absorption corrections were applied based on indexed and measured faces. The structure was solved and refined in SHELXTL6.1, using full matrix least squares refinem ent. The non H atoms were refined with anisotropic thermal parameters and all of the H atoms were calculated in idealized positions and refined riding on their parent atoms. In the final cycle of refinement, 7644 reflections (of which 6905 are observed w ith I > 2 (I)) were used to refine 457 parameters and the resulting R 1 wR 2 and S (goodness of fit) were 1.45 %, 3.69 % and 1.052 respectively. The refinement was carried out by minimizing the wR 2 function using F 2 rather than F values. R 1 is calculated to provide a reference to the conventional R value but its function is not minimized. SHELXTL6 (2008). Bruker AXS, Madison, Wisconsin, USA. Table A 38 Crystal data and structure refinement for 13 Item Value Identification code orei33 Empirical formula C34 H29 F12 N O2 W Formula weight 895.43 Temperature 100(2) K Wavelength 0.71073 Crystal system Monoclinic Space group P2 1 /c Unit cell dimensions a = 10.6462(5) = 90. b = 15.7072(7) = 95.374(1).

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337 Table A 39 Continued. Item Value Unit cell dimensions (continued) c = 19.9882(9) = 90. Volume 3327.8(3) 3 Z 4 Density (calculated) 1.787 Mg/m 3 Absorption coefficient 3.571 mm 1 F( 000) 1752 Crystal size 0.29 x 0.17 x 0.05 mm 3 Theta range for data collection 1.65 to 27.50. Index ranges Reflections collected 104900 Independent reflections 7644 [R(int) = 0.0372] Completeness to theta = 27.50 100.0 % Abso rption correction Numerical Max. and min. transmission 0.8388 and 0.4230 Refinement method Full matrix least squares on F 2 Data / restraints / parameters 7644 / 0 / 457 Goodness of fit on F 2 1.052 Final R indices [I>2sigma(I)] R1 = 0.0145, wR2 = 0.0369 [69 05] R indices (all data) R1 = 0.0178, wR2 = 0.0376 Largest diff. peak and hole 0.827 and 0.431 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants. Table A 39 Atomic coordinates ( x 10 4 ) and equivalent isotropic displacem ent parameters ( 2 x 10 3 ) for 13 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) W1 8673(1) 598(1) 7892(1) 11(1) F1 7832(1) 1208(1) 6441(1) 32(1) F2 8375(1) 2040(1) 7270(1) 28(1) F3 6512(1) 2135(1) 6766(1) 36(1) F4 6882(1) 2032(1) 8278(1) 28(1) F5 5113(1) 1625(1) 7770(1) 32(1) F6 6092(1) 823(1) 8517(1) 27(1) F7 8904(1) 2190(1) 9782(1) 24(1) F8 10130(1) 2773(1) 9122(1) 26(1) F9 8534(1) 3467(1) 9412(1) 25(1) F10 9046(1) 3305(1) 7921(1) 27(1) F11 7195(1) 36 03(1) 8206(1) 23(1) F12 7438(1) 2605(1) 7491(1) 21(1) O1 8067(1) 570(1) 7793(1) 15(1) O2 8856(1) 1626(1) 8453(1) 15(1) N1 6835(1) 861(1) 7957(1) 13(1) C1 6965(2) 903(1) 7468(1) 15(1) C2 6095(2) 235(1) 7109(1) 13(1) C3 6036(2) 584(1) 7386(1) 13(1) C4 520 2(2) 1178(1) 7062(1) 14(1) C5 4463(2) 974(1) 6482(1) 15(1) C6 4521(2) 166(1) 6194(1) 15(1)

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338 Table A 39 Continued. Atom X Y Z U(eq) C7 5329(2) 424(1) 6517(1) 15(1) C8 7423(2) 1581(1) 6980(1) 23(1) C9 6256(2) 1353(1) 8010(1) 21(1) C10 3713(2) 54(1) 555 6(1) 20(1) C11 8117(2) 2293(1) 8633(1) 15(1) C12 6823(2) 1997(1) 8808(1) 13(1) C13 6242(2) 1309(1) 8456(1) 13(1) C14 5050(2) 1043(1) 8618(1) 15(1) C15 4448(2) 1443(1) 9114(1) 17(1) C16 5014(2) 2125(1) 9471(1) 18(1) C17 6188(2) 2393(1) 9309(1) 17(1) C18 892 4(2) 2690(1) 9241(1) 20(1) C19 7953(2) 2959(1) 8059(1) 18(1) C20 4356(2) 2569(1) 10010(1) 28(1) C21 9510(2) 830(1) 7111(1) 15(1) C22 10556(2) 552(1) 7576(1) 16(1) C23 10325(2) 268(1) 8256(1) 15(1) C24 9449(2) 1152(1) 6394(1) 19(1) C25 8051(2) 1245(1) 6143( 1) 24(1) C26 10067(2) 516(1) 5947(1) 35(1) C27 10080(2) 2033(1) 6374(1) 31(1) C28 11910(2) 610(1) 7410(1) 22(1) C29 11243(2) 60(1) 8818(1) 18(1) C30 12231(2) 520(1) 8764(1) 26(1) C31 13060(2) 703(1) 9321(1) 32(1) C32 12921(2) 314(1) 9931(1) 32(1) C33 11 938(2) 250(1) 9992(1) 29(1) C34 11096(2) 435(1) 9438(1) 22(1) Table A 40 Bond lengths [] for 13 Bond Length Bond Length W1 C21 1.9046(16) W1 C23 1.9106(18) W1 O1 1.9489(11) W1 O2 1.9631(11) W1 N1 2.0158(14) W1 C22 2.1589(18) F1 C8 1.335(2) F2 C8 1.331(2) F3 C8 1.343(2) F4 C9 1.342(2) F5 C9 1.336(2) F6 C9 1.336(2) F7 C18 1.339(2) F8 C18 1.334(2) F9 C18 1.3435(19 ) F10 C19 1.337(2) F11 C19 1.3436(19) F12 C19 1.335(2) O1 C1 1.389(2) O2 C11 1.3797(19) N1 C13 1.417(2) N1 C3 1.426(2) C1 C2 1.533(2) C1 C9 1.548(2) C1 C8 1.552(2) C2 C3 1.404(2) C2 C7 1.404(2) C3 C4 1.404(2) C4 C5 1.377(2) C5 C6 1.397(2) C6 C7 1.383(2) C6 C10 1.511(2) C11 C12 1.525(2) C11 C19 1.550(2) C11 C18 1.551(2) C12 C13 1.402(2) C12 C17 1.404(2) C13 C14 1.402(2) C14 C15 1.382(2) C15 C16 1.393(3) C16 C17 1.386(2) C16 C20 1.510(2) C21 C22 1.450(3) C21 C24 1.514(2)

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339 Table A 40 Continued Bond Length Bond Length C22 C23 1.473(2) C22 C28 1.512(2) C23 C29 1.455(2) C24 C26 1.531(3) C24 C25 1.533(3) C 24 C27 1.540(3) C29 C34 1.394(3) C29 C30 1.403(3) C30 C31 1.385(3) C31 C32 1.383(3) C32 C33 1.386(3) C33 C34 1.389(3) Symmetry transformations used to generate equivalent atoms: Table A 40 Bond angles [] for 13 Bon d Angle Bond Angle C21 W1 C23 83.09(7) C21 W1 O1 105.78(6) C23 W1 O1 93.85(6) C21 W1 O2 106.38(6) C23 W1 O2 88.16(6) O1 W1 O2 14 7.78(5) C21 W1 N1 122.99(7) C23 W1 N1 153.60(6) O1 W1 N1 83.38(5) O2 W1 N1 80.83(5) C21 W1 C22 41.22(7) C23 W1 C22 41.90(7) O1 W1 C22 104.24(6) O2 W1 C22 98.61(6) N1 W1 C22 163.57(6) C1 O1 W1 131.31(10) C11 O2 W1 138.19(11) C13 N1 C3 116.32(14) C13 N1 W1 1 30.22(11) C3 N1 W1 113.36(10) O1 C1 C2 114.02(13) O1 C1 C9 106.85(14) C2 C1 C9 109.08(14) O1 C1 C8 104.57(14) C2 C1 C8 112.85(14) C9 C1 C8 109.19(14) C3 C2 C7 118.82(15) C3 C2 C1 119.39(15) C7 C2 C1 121.78(15) C4 C3 C2 118.50(15) C4 C3 N1 118.07(14) C2 C3 N1 123.32(15) C5 C4 C3 121.35(15) C4 C5 C6 120.94(16) C7 C6 C5 117.82(16) C7 C6 C10 121.38(15) C5 C6 C10 120.79(15) C6 C7 C2 122.54(15) F2 C8 F1 107.27(15) F2 C8 F3 106.62(14) F1 C8 F3 107.86(15) F2 C8 C1 111.70(15) F1 C8 C1 110.52(14) F3 C8 C1 112.62(16) F6 C9 F5 106.99(15) F6 C9 F4 106.68(15) F5 C9 F4 106.91(14) F6 C9 C1 110.76(13) F5 C9 C1 112.46(15) F4 C9 C1 112.69(15) O2 C11 C12 112.18(13) O2 C11 C19 110.28(13) C12 C11 C19 109.54(14) O2 C11 C18 102.83(14) C12 C11 C18 112.89(13) C19 C11 C18 108.93(13) C 13 C12 C17 118.71(15) C13 C12 C11 119.03(14) C17 C12 C11 122.26(15) C14 C13 C12 118.67(15) C14 C13 N1 119.17(15) C12 C13 N1 122.14(15) C15 C14 C13 121.41(16) C14 C15 C16 120.66(16) C17 C16 C15 118.04(15) C17 C16 C20 121.02(17) C15 C16 C20 120.93(17) C16 C1 7 C12 122.50(16) F8 C18 F7 106.83(15) F8 C18 F9 106.42(14) F7 C18 F9 107.32(13) F8 C18 C11 111.85(14) F7 C18 C11 110.29(14) F9 C18 C11 113.77(15) F12 C19 F10 106.87(13) F12 C19 F11 106.97(15) F10 C19 F11 106.87(13) F12 C19 C11 110.96(13) F10 C19 C11 112.80 (15) F11 C19 C11 112.03(13) C22 C21 C24 132.01(15) C22 C21 W1 78.84(10) C24 C21 W1 149.07(14) C21 C22 C23 119.89(15)

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340 Table A 4 1 Continued Bond Angle Bond Angle C21 C22 C28 122.13(16) C23 C22 C28 117.78(16) C21 C22 W1 59.94(9) C23 C22 W1 60.00(9) C28 C22 W1 173.09(13) C29 C23 C22 128.45(16) C29 C23 W1 151.93(13) C22 C23 W1 78.11(10) C21 C24 C26 110.58(15) C21 C24 C25 107.23(14) C2 6 C24 C25 109.11(16) C21 C24 C27 110.19(15) C26 C24 C27 111.07(16) C25 C24 C27 108.54(16) C34 C29 C30 119.30(17) C34 C29 C23 117.92(16) C30 C29 C23 122.75(17) C31 C30 C29 119.94(19) C32 C31 C30 120.3(2) C31 C32 C33 120.31(19) C32 C33 C34 119.92(19) C33 C34 C29 120.24(18) Symmetry transformations used to generate equivalent atoms: Table A 41 Anisotropic displacement parameters ( 2 x 10 3 ) for 13 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 W1 9(1) 13(1) 11(1) 1(1) 0(1) 0(1) F1 34(1) 38(1) 24(1) 6(1) 5(1) 14(1) F2 24(1) 23(1) 36(1) 7(1) 7(1) 12(1) F3 33(1) 20(1) 49(1) 16(1) 18(1) 4(1) F4 25(1) 20(1) 39(1) 13 (1) 0(1) 4(1) F5 18(1) 29(1) 49(1) 14(1) 5(1) 10(1) F6 31(1) 25(1) 26(1) 6(1) 10(1) 2(1) F7 28(1) 29(1) 15(1) 1(1) 3(1) 2(1) F8 18(1) 31(1) 28(1) 10(1) 0(1) 8(1) F9 30(1) 20(1) 26(1) 11(1) 2(1) 2(1) F10 21(1) 29(1) 31(1) 8(1) 7(1 ) 7(1) F11 27(1) 16(1) 27(1) 2(1) 6(1) 4(1) F12 27(1) 22(1) 14(1) 2(1) 1(1) 1(1) O1 11(1) 13(1) 21(1) 2(1) 3(1) 0(1) O2 12(1) 16(1) 16(1) 3(1) 1(1) 1(1) N1 11(1) 14(1) 13(1) 2(1) 1(1) 0(1) C1 13(1) 12(1) 20(1) 1(1) 2(1) 0(1) C2 9(1) 14(1) 17(1) 0(1) 0(1) 1(1) C3 11(1) 15(1) 13(1) 0(1) 3(1) 2(1) C4 13(1) 14(1) 16(1) 0(1) 4(1) 1(1) C5 12(1) 18(1) 15(1) 5(1) 2(1) 1(1) C6 12(1) 20(1) 14(1) 1(1) 2(1) 3(1) C7 14(1) 15(1) 17(1) 2(1) 1(1) 2(1) C8 22(1) 19(1) 27(1 ) 5(1) 6(1) 4(1) C9 16(1) 16(1) 30(1) 6(1) 3(1) 1(1) C10 19(1) 24(1) 18(1) 0(1) 3(1) 2(1) C11 16(1) 14(1) 13(1) 2(1) 1(1) 2(1) C12 15(1) 13(1) 12(1) 2(1) 2(1) 1(1) C13 13(1) 13(1) 11(1) 2(1) 2(1) 3(1) C14 14(1) 16(1) 15(1) 4(1) 0 (1) 1(1) C15 14(1) 20(1) 18(1) 7(1) 5(1) 3(1) C16 21(1) 19(1) 15(1) 4(1) 6(1) 6(1) C17 21(1) 15(1) 14(1) 0(1) 2(1) 2(1) C18 21(1) 19(1) 20(1) 5(1) 2(1) 2(1) C19 17(1) 17(1) 20(1) 0(1) 5(1) 3(1)

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341 Table A 4 2 Continued. U 11 U 22 U 33 U 23 U 13 U 12 C20 32(1) 30(1) 25(1) 3(1) 13(1) 4(1) C21 12(1) 19(1) 15(1) 3(1) 3(1) 2(1) C22 13(1) 18(1) 19(1) 4(1) 3(1) 1(1) C23 13(1) 14(1) 17(1) 1(1) 0(1) 0(1) C24 16(1) 29(1) 12(1) 1(1) 2(1) 2(1) C25 19(1) 37(1) 15(1) 4(1) 0(1) 2(1) C26 32(1) 55(1) 18(1) 4(1) 7(1) 10(1) C27 29(1) 40(1) 22(1) 11(1) 3(1) 13(1) C28 11(1) 30(1) 25(1) 1(1) 4(1) 1(1) C29 12(1) 20(1) 21(1) 5(1) 1(1) 3(1) C30 22(1) 25(1) 30(1) 4(1) 1(1) 4(1) C31 22(1) 31(1) 42(1) 14(1) 2(1) 7(1) C32 2 2(1) 43(1) 30(1) 22(1) 7(1) 6(1) C33 24(1) 42(1) 20(1) 9(1) 1(1) 6(1) C34 18(1) 29(1) 21(1) 7(1) 2(1) 1(1) Figure A 172 Molecular Structure of 14 X Ray experimental : X Ray Intensity data were collected at 100 K on a Bruker DUO diffractometer using MoK radiation ( = 0.71073 ) and an APEXII CCD area detector. Raw data frames were read by program SAINT 1 and integrated using 3D profiling algorithms. The resulting data were reduced to produce hkl reflections and their intensities and estimated standard deviations. The data were corrected for Lorentz

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342 and polarization effects and numerical absorption corrections were applied based on indexed and measured faces. The structure was solved and refined in SHELXT L6.1, using full matrix least squares refinement. The non H atoms were refined with anisotropic thermal parameters and all of the H atoms were calculated in idealized positions and refined riding on their parent atoms. The W center is disordered and was refined in two positions with their site occupation factors dependently refine to 0.930(1) and 0.070(1), for the major and minor parts respectively. It is worth noting here that the major W center is symmetrically coordinated to the C21/C23 atoms while W2 is asymmetrically coordinated to them; 1.882(3)/1.908(3) for W1 compared to2.387(6)/1.768(4) In the final cycle of refinement, 7570 reflections (of which 6697 are observed with I > 2 (I)) were used to refine 441 parameters and the resulting R 1 wR 2 and S (goodness of fit) were 2.20 %, 4.82 % and 1.089 respectively. The refinement was carried out by minimizing the wR 2 function using F 2 rather than F values. R 1 is calculated to provide a reference to the conventional R value but its function is not minimized. Table A 42 Crystal data and structure refinement for 14 Item Value Identification code orei35 Empirical formula C 32 H 33 F 12 N O 2 W Formula weight 875.44 Temperature 100(2) K Wavelength 0.71073 Crystal system Monoclinic Space group P2 1 /c Unit cell dimensions a = 17.6465(14) = 90. b = 9.8689(8) = 104.391(1). c = 19.5331(16) = 90. Volume 3295.0(5) 3 Z 4 Density (calculated) 1.765 Mg/m 3 Absorption coefficient 3.604 mm 1 F(000) 1720 Crystal size 0.19 x 0.09 x 0.02 mm 3 Theta range for data collection 2.15 to 27.50.

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343 Table A 4 3 Continued. Item Value Index ranges Reflections collected 59838 Independent reflections 7570 [R(int) = 0.0320] Completeness to theta = 27.50 100.0 % Absorption correction Semi empirical from equivalents Max. and min. transmission 0.9314 and 0.5475 Refinement method Full matrix least squares on F 2 Data / restraints / parameters 7570 / 0 / 441 Goodness of fit on F 2 1.089 Final R indices [I>2sigma(I)] R1 = 0.0220, wR2 = 0.0482 [6697] R indices (all data) R1 = 0.0276, wR2 = 0.0496 Largest diff. peak and hole 0.866 and 0.821 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants. Table A 43 Atomic coordinates ( x 10 4 ) and equi valent isotropic displacement parameters ( 2 x 10 3 ) for 14 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) W1 2613(1) 1137(1) 8118(1) 15(1) W2 2678(2) 1030(3) 8412(3) 38(1) F1 1224(1) 963(2) 9763(1) 32(1) F2 809(1) 2705(2) 9123(1) 34(1) F3 22(1) 1070(2) 9161(1) 32(1) F4 659(1) 545(2) 7273(1) 30(1) F5 248(1) 2288(2) 7732(1) 33(1) F6 267(1) 334(2) 7801(1) 31(1) F7 4121(1) 506(2) 6899(1) 40(1) F8 4953(1) 483(2) 7909(1) 42(1) F9 4865(1) 1236(2) 7222(1) 45(1) F1 0 3652(1) 2318(2) 8712(1) 33(1) F11 4386(1) 3044(2) 8064(1) 44(1) F12 4794(1) 1458(2) 8819(1) 52(1) O1 1715(1) 1362(2) 8529(1) 21(1) O2 3606(1) 223(2) 8162(1) 23(1) N1 2182(1) 767(2) 7962(1) 18(1) C1 1029(1) 680(3) 8526(1) 18(1) C2 1154(1) 845(2) 8626 (1) 17(1) C3 1712(1) 1484(3) 8334(1) 18(1) C4 1799(2) 2893(3) 8414(1) 22(1) C5 1362(2) 3640(3) 8776(1) 23(1) C6 821(2) 3015(3) 9078(1) 22(1) C7 722(1) 1628(3) 8992(1) 20(1) C8 757(2) 1359(3) 9144(1) 24(1) C9 405(2) 969(3) 7824(1) 23(1) C10 358(2) 382 2(3) 9491(2) 30(1) C11 3800(2) 856(3) 7790(1) 22(1) C12 3108(1) 1465(3) 7245(1) 21(1) C13 2356(1) 1429(2) 7370(1) 19(1)

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344 Table A 4 4 Continued. Atom X Y Z U(eq) C14 1738(2) 1999(3) 6858(1) 22(1) C15 1852(2) 2570(3) 6246(1) 25(1) C16 2592(2) 2604(3) 6112(1) 25(1) C17 3207(2) 2063(3) 6623(1) 25(1) C18 4443(2) 281(3) 7451(2) 33(1) C19 4166(2) 1933(3) 8348(2) 31(1) C20 2719(2) 3167(3) 5431(2) 34(1) C21 2509(2) 2400(3) 7378(1) 24(1) C22 2945(2) 3188(3) 7978(2) 28(1) C23 3166(2) 2579(3) 8677(1) 25(1) C 24 2188(2) 2786(3) 6614(2) 30(1) C25 1922(2) 1468(3) 6207(2) 37(1) C26 1479(2) 3727(3) 6554(2) 36(1) C27 2805(2) 3456(4) 6292(2) 42(1) C28 3201(2) 4628(3) 7880(2) 35(1) C29 3631(2) 3070(3) 9381(2) 35(1) C30 3195(2) 4179(4) 9680(2) 59(1) C31 4448(2) 3544(4) 9343(2) 56(1) C32 3717(2) 1810(4) 9859(2) 51(1) Table A 44 Bond lengths [] for 14 Bond Length Bond Length W1 C21 1.882(3) W1 C23 1.908(3) W1 O2 1.9549(17) W1 O1 1.9587(17) W1 N1 2.022(2) W1 C22 2.144(3) W2 C21 2.387(6) W2 C23 1.768(4) W2 O1 1.800(3) W2 O2 1.989(3) W2 N1 2.074(3) W2 C22 2.383(5) W2 C21 2.387(6) F1 C8 1.341(3) F2 C8 1. 334(3) F3 C8 1.337(3) F4 C9 1.333(3) F5 C9 1.334(3) F6 C9 1.332(3) F7 C18 1.336(4) F8 C18 1.333(3) F9 C18 1.345(3) F10 C19 1.338(3) F11 C19 1.330(3) F12 C19 1.337(3) O1 C1 1.384(3) O2 C11 1.380(3) N1 C3 1.420(3) N1 C13 1.426(3) C1 C2 1.527(3 ) C1 C8 1.556(3) C1 C9 1.557(3) C2 C7 1.400(3) C2 C3 1.403(3) C3 C4 1.403(4) C4 C5 1.382(4) C5 C6 1.386(4) C6 C7 1.384(4) C6 C10 1.510(3) C11 C12 1.530(4) C11 C19 1.544(4) C11 C18 1.556(4) C12 C17 1.400(4) C12 C13 1.407(3) C13 C14 1.401(3) C 14 C15 1.381(4) C15 C16 1.393(4) C16 C17 1.386(4) C16 C20 1.510(4) C21 C22 1.456(4) C21 C24 1.508(4) C22 C23 1.453(4) C22 C28 1.517(4) C23 C29 1.496(4) C24 C27 1.536(4) C24 C25 1.536(4) C24 C26 1.539(4) C29 C30 1.533(5) C29 C31 1.535(5) C29 C 32 1.539(5) Symmetry transformations used to generate equivalent atoms:

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345 Table A 45 Bond angles [] for 14 Bond Angle Bond Angle C21 W1 C23 83.30(12) C21 W1 O2 104.73(9) C23 W1 O2 89.61(10) C21 W1 O1 107.80(9) C23 W1 O1 91.81(9) O2 W1 O1 147.39(8) C21 W1 N1 122.65(10) C23 W1 N1 154.02(10) O2 W1 N1 82.92(8) O1 W1 N1 81.68(8) C21 W1 C22 41.79(11) C23 W1 C22 41.52(11) O2 W1 C22 99.81(9) O1 W1 C22 102.70(8) N1 W1 C22 164.43(10) C23 W2 O1 102.23(16) C23 W2 O2 92.69(15) O1 W2 O2 164.89(18) C23 W2 N1 170.7(3) O1 W2 N1 84.13(12) O2 W2 N1 80.77(12) C23 W2 C22 37.41(14) O1 W2 C22 99.12(15) O2 W2 C22 91.27(16) N1 W2 C22 135.5(3) C23 W2 C21 72.92(18) O1 W2 C21 94.62(19) O2 W2 C21 87.46(18) N1 W2 C21 100.1(2) C22 W2 C21 35.55(12) C1 O1 W2 139.76(18) C1 O1 W1 137.67(15) W2 O1 W1 16.71(16) C11 O2 W1 132.08(16) C11 O2 W2 139.98(18) W1 O2 W2 16.54(14) C3 N1 C13 117.2 (2) C3 N1 W1 129.19(16) C13 N1 W1 113.54(15) C3 N1 W2 116.6(2) C13 N1 W2 125.63(19) W1 N1 W2 15.89(14) O1 C1 C2 112.3(2) O1 C1 C8 103.1(2) C2 C1 C8 112.9(2) O1 C1 C9 109.9(2) C2 C1 C9 109.9(2) C8 C1 C9 108.5(2) C7 C2 C3 119.1(2) C7 C2 C1 121.9(2) C3 C2 C1 119.0(2) C4 C3 C2 117.9(2) C4 C3 N1 119.2(2) C2 C3 N1 122.8(2) C5 C4 C3 121.7(2) C4 C5 C6 120.8(2) C7 C6 C5 117.9(2) C7 C6 C10 121.2(2) C5 C6 C10 120.9(2) C6 C7 C2 122.6(2) F2 C8 F3 106.7(2) F2 C8 F1 106.7(2) F3 C8 F1 107.3(2) F2 C8 C1 111.6(2) F3 C8 C1 11 4.6(2) F1 C8 C1 109.6(2) F6 C9 F4 107.5(2) F6 C9 F5 107.5(2) F4 C9 F5 107.3(2) F6 C9 C1 111.9(2) F4 C9 C1 110.4(2) F5 C9 C1 112.0(2) O2 C11 C12 114.2(2) O2 C11 C19 105.9(2) C12 C11 C19 110.0(2) O2 C11 C18 104.2(2) C12 C11 C18 112.8(2) C19 C11 C18 109.3(2) C17 C12 C13 119.2(2) C17 C12 C11 121.3(2) C13 C12 C11 119.6(2) C14 C13 C12 117.8(2) C14 C13 N1 118.4(2) C12 C13 N1 123.7(2) C15 C14 C13 121.8(2) C14 C15 C16 121.1(2) C17 C16 C15 117.3(2) C17 C16 C20 121.0(2) C15 C16 C20 121.7(3) C16 C17 C12 122.9(2) F8 C18 F7 107.1(2) F8 C18 F9 106.4(2) F7 C18 F9 107.4(2) F8 C18 C11 111.3(2) F7 C18 C11 110.2(2) F9 C18 C11 114.1(2) F11 C19 F12 107.3(2) F11 C19 F10 107.1(2) F12 C19 F10 106.9(3) F11 C19 C11 112.7(2) F12 C19 C11 111.9(2) F10 C19 C11 110.5(2) C22 C21 C24 130.9(2 ) C22 C21 W1 78.78(16) C24 C21 W1 150.2(2) C22 C21 W2 72.07(17)

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346 Table A 4 6 Continued. Bond Angle Bond Angle C24 C21 W2 156.6(2) W1 C21 W2 7.04(7) C23 C22 C21 120.0(2) C23 C22 C28 119.2(3) C21 C22 C28 120.8(3) C23 C22 W1 60.53(15) C21 C22 W1 59.43(14) C28 C22 W1 178.6(2) C23 C22 W2 47.66(18) C21 C22 W2 72.38(19) C28 C22 W2 166.8(2) W1 C22 W2 13.10(11) C22 C23 C29 133.4(3) C22 C23 W2 94.9(3) C29 C23 W2 131.7(3) C22 C23 W1 77.96(17) C29 C23 W1 148.6(2) W2 C23 W1 17.25(17) C21 C24 C27 112.6(3) C21 C24 C25 106.9(2) C27 C24 C25 108.0(2) C21 C24 C26 109.1(2) C27 C24 C26 110.7(2) C25 C24 C26 109.4(3) C23 C29 C30 111.6(3) C23 C29 C31 111.2(3 ) C30 C29 C31 111.5(3) C23 C29 C32 104.2(3) C30 C29 C32 109.2(3) C31 C29 C32 108.8(3) Symmetry transformations use d to generate equivalent atoms: Table A 46 Anisotropic displacement parameters (2x 103) for 14 The anisotr opic displacement factor exponent takes the form: 2 2 [ h 2 a 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 W1 14(1) 13(1) 18(1) 2(1) 4(1) 1(1) F1 39(1) 37(1) 21(1) 6(1) 7(1) 1(1) F2 41(1) 20(1) 48(1) 6(1) 23(1) 1(1) F3 28(1) 31(1) 43(1) 3(1) 21(1) 1(1) F4 30(1) 40(1) 20(1) 5(1) 4 (1) 7(1) F5 33(1) 24(1) 41(1) 12(1) 7(1) 9(1) F6 18(1) 39(1) 34(1) 10(1) 2(1) 3(1) F7 35(1) 42(1) 47(1) 8(1) 16(1) 12(1) F8 22(1) 46(1) 59(1) 9(1) 13(1) 15(1) F9 23(1) 53(1) 66(1) 14(1) 23(1) 4(1) F10 32(1) 31(1) 34(1) 9(1) 4(1) 3( 1) F11 32(1) 26(1) 77(1) 3(1) 18(1) 12(1) F12 30(1) 41(1) 70(1) 12(1) 19(1) 3(1) O1 18(1) 18(1) 28(1) 2(1) 9(1) 1(1) O2 16(1) 19(1) 32(1) 1(1) 4(1) 0(1) N1 15(1) 15(1) 24(1) 0(1) 8(1) 0(1) C1 16(1) 18(1) 22(1) 1(1) 6(1) 1(1) C2 17(1) 18(1) 16(1) 1(1) 1(1) 0(1) C3 16(1) 18(1) 20(1) 1(1) 3(1) 2(1) C4 20(1) 19(1) 28(1) 1(1) 7(1) 2(1) C5 26(1) 17(1) 26(1) 4(1) 5(1) 1(1) C6 21(1) 23(1) 21(1) 3(1) 4(1) 5(1) C7 20(1) 23(1) 19(1) 0(1) 5(1) 0(1) C8 25(1) 21(2) 29(1) 1(1 ) 10(1) 2(1) C9 21(1) 22(1) 27(1) 7(1) 6(1) 3(1) C10 35(2) 27(2) 32(1) 5(1) 15(1) 4(1) C11 16(1) 18(1) 34(1) 0(1) 8(1) 0(1) C12 17(1) 17(1) 30(1) 2(1) 7(1) 0(1) C13 18(1) 14(1) 25(1) 3(1) 7(1) 0(1) C14 17(1) 21(1) 28(1) 2(1) 7(1) 1(1) C15 24(1) 24(1) 26(1) 0(1) 5(1) 4(1)

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347 Table A 4 7 Continued. U 11 U 22 U 33 U 23 U 13 U 12 C16 30(1) 21(1) 27(1) 2(1) 11(1) 0(1) C17 22(1) 23(1) 33(1) 2(1) 14(1) 1(1) C18 19(1) 34(2) 47(2) 3(1) 13(1) 5(1) C19 17(1) 25(2) 47(2) 2(1) 1(1) 2(1) C20 40(2) 36(2) 29(1) 3(1) 14(1) 0(1) C21 23(1) 21(1) 30(1) 6(1) 11(1) 5(1) C22 21(1) 25(2) 41(2) 3(1) 15(1) 3(1) C23 19(1) 24(1) 32(1) 3(1) 8(1) 2(1) C24 31(2) 31(2) 31(1) 11(1) 14(1) 9(1) C25 40(2) 43(2) 27(1) 7(1) 9(1) 7(1) C26 36(2 ) 38(2) 34(2) 13(1) 13(1) 10(1) C27 45(2) 46(2) 43(2) 14(2) 24(2) 6(2) C28 35(2) 22(2) 53(2) 1(1) 21(1) 2(1) C29 30(2) 39(2) 34(2) 7(1) 2(1) 4(1) C30 65(3) 71(3) 39(2) 23(2) 10(2) 3(2) C31 36(2) 68(3) 59(2) 12(2) 0(2) 17(2) C32 43( 2) 72(3) 32(2) 4(2) 4(1) 7(2) Figure A 173 Molecular Structure of 15 X Ray experimental : X Ray Intensity data were collected at 100 K on a Bruker DUO diffractometer using MoK radiation ( = 0.71073 ) and an APEXII CCD area detector.

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348 Raw data frames were read by program SAINT 1 and integrated using 3D profiling algorithms. The resulting data were reduced to produce hkl reflections and their intensities and estimated stan dard deviations. The data were corrected for Lorentz and polarization effects and numerical absorption corrections were applied based on indexed and measured faces. The structure was solved and refined in SHELXTL6.1, using full matrix least squares refi nement. The non H atoms were refined with anisotropic thermal parameters and all of the H atoms were calculated in idealized positions and refined riding on their parent atoms. The C30 C31 unit is disordered and was refined against C3 In the final cycle of refinement, 7274 reflections (of which 6082 are observed with I > 2 (I)) were used to refine 446 parameters and the resulting R 1 wR 2 and S (goodness of fit) were 2.09 %, 4.48 % and 0.962 respectively. The refinement was carried out by minimizing the wR 2 function using F 2 rather than F values. R 1 is calculated to provide a reference to the conventional R value but its function is not minimized. SHELXTL6 (2008). Bruker AXS, Madison, Wisconsin, USA. T able A 47 Crystal data and structure refinement for 15 Item Value Identification code orei34 Empirical formula C 33 H 33 F 12 N O 2 W Formula weight 887.45 Temperature 100(2) K Wavelength 0.71073 Crystal system Monoclinic Space group P2 1 /c Unit cell dimensions a = 19.6072(11) = 90. b = 9.2537(5) = 112.5630(10). c = 18.9077(10) = 90. Volume 3168.0(3) 3 Z 4 Density (calculated) 1.861 Mg/m 3 Absorption coefficient 3.750 mm 1

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349 T able A 4 8 Continued Item Value F(000) 1744 Crystal size 0.16 x 0.13 x 0.01 mm 3 Theta range for data collection 2.17 to 27.50. Index ranges Reflections collected 52389 Independent reflections 7274 [R(int) = 0.0410] Completeness to theta = 27.50 100.0 % Absorption correction Numerical Max. and min. transmission 0.9529 and 0.5941 Refinement method Full matrix least squares on F 2 Data / restraints / parameters 7274 / 0 / 446 Goodness of fit on F 2 0.962 Final R indices [I>2sigma(I)] R1 = 0.0209, wR2 = 0.0448 [6082] R indices (all data) R1 = 0.0297, wR2 = 0.0462 Largest diff. peak and hole 1.338 and 0.787 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants. Table A 48 Atomic coordinates ( x 10 4 ) and equi valent isotropic displacement parameters (2x 10 3 ) for 15 U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. Atom X Y Z U(eq) W1 2478(1) 775(1) 2714(1) 13(1) F1 826(1) 2223(2) 1992(1) 26(1) F2 146(1) 423(2) 2012(1) 27(1) F3 210(1) 2259(2) 2733(1) 25(1) F4 388(1) 689(2) 3386(1) 27(1) F5 921(1) 1027(2) 4164(1) 26(1) F6 1521(1) 900(2) 4142(1) 26(1) F7 3997(1) 4513(2) 3826(1) 21(1) F8 4397(1) 3594(2) 3016(1) 19(1) F9 5088(1) 3576(2) 4214(1) 21(1) F10 4774(1) 777(2) 3183(1) 24(1 ) F11 5187(1) 742(2) 4415(1) 20(1) F12 4257(1) 577(1) 3754(1) 20(1) O1 1499(1) 397(2) 2734(1) 16(1) O2 3400(1) 1895(2) 3117(1) 14(1) N1 2833(1) 166(2) 3826(1) 13(1) C1 1281(1) 717(3) 3094(2) 16(1) C2 1898(1) 1802(3) 3509(2) 15(1) C3 2617(1) 1283(3) 390 7(1) 13(1) C4 3160(1) 2263(3) 4349(2) 17(1) C5 3002(2) 3715(3) 4362(2) 17(1) C6 2306(2) 4261(3) 3926(2) 19(1) C7 1758(2) 3286(3) 3525(2) 18(1) C8 608(2) 1416(3) 2452(2) 20(1) C9 1020(1) 31(3) 3699(2) 18(1) C10 2161(2) 5868(3) 3853(2) 27(1) C11 4030( 1) 1943(2) 3777(1) 12(1)

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350 Table A 4 9 Continued. Atom X Y Z U(eq) C12 3863(1) 1823(2) 4503(1) 12(1) C13 3290(1) 903(3) 4496(1) 13(1) C14 3168(1) 747(3) 5178(2) 17(1) C15 3597(2) 1462(3) 5840(2) 18(1) C16 4167(2) 2375(3) 5856(2) 18(1) C17 4287(1) 2537(3) 5 181(1) 16(1) C18 4387(1) 3415(3) 3714(2) 16(1) C19 4572(1) 713(3) 3786(1) 15(1) C20 4659(2) 3116(3) 6584(2) 29(1) C21 2530(2) 436(3) 1918(2) 18(1) C22 2220(1) 869(3) 1500(2) 19(1) C23 2092(1) 2132(3) 1906(2) 18(1) C24 2782(2) 1836(3) 1678(2) 22(1) C25 21 68(2) 2544(3) 992(2) 30(1) C26 3464(2) 1553(3) 1488(2) 29(1) C27 2998(2) 2871(3) 2360(2) 26(1) C28 1984(2) 1014(3) 639(2) 28(1) C29 1148(2) 698(4) 215(2) 41(1) C30 600(3) 1599(6) 545(3) 29(1) C31 644(3) 3253(5) 506(3) 30(1) C30' 664(5) 1767(9) 101(5) 30 (2) C31' 532(4) 2126(9) 823(5) 24(2) C32 1017(2) 3825(5) 1272(2) 53(1) C33 1855(2) 3609(3) 1585(2) 33(1) Table A 50 Bond lengths [] for 15 Bond Length Bond Length W1 C23 1.897(3) W1 C21 1.911(3) W1 O1 1.9648(17) W1 O2 1.9664(16) W1 N1 2.023(2) W1 C22 2.156(3) F1 C8 1.336(3) F2 C8 1.335(3) F3 C8 1.349(3) F4 C9 1.330(3) F5 C9 1.339(3) F6 C9 1.332(3) F7 C18 1.337(3) F8 C18 1.337(3) F9 C18 1.345(3) F10 C19 1.343(3) F11 C19 1.331(3) F12 C19 1.335(3) O1 C1 1.390(3) O2 C11 1.379(3) N1 C13 1.416(3) N1 C3 1.432(3) C1 C2 1.536(4) C1 C8 1.550(4) C1 C9 1.558(3) C2 C7 1.403(3) C2 C3 1.403(3) C3 C4 1.404(3) C4 C5 1.381(4) C5 C6 1.390(4) C6 C7 1.386(4) C6 C10 1.511(4) C11 C12 1.532(3) C11 C19 1.553(3) C11 C18 1.557(3) C12 C17 1.398(3) C12 C13 1.405(3) C13 C14 1.406(3) C14 C15 1.379(4) C15 C16 1.391(4) C16 C17 1.392(3) C16 C20 1.509(4) C21 C22 1.443(4 ) C21 C24 1.516(4) C22 C23 1.473(4) C22 C28 1.517(4) C23 C33 1.496(4) C24 C27 1.530(4) C24 C26 1.536(4) C24 C25 1.538(4) C28 C29 1.550(4) C29 C30' 1.330(9)

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351 Table A 50 Continued Bond Length Bond Length C29 C30 1.659(6) C30 C31 1.536(7) C31 C32 1.449(6) C30' C31' 1.521(12) C31' C32 1.865(9) C32 C33 1.531(4) Symmetry transformations used to generate equivalent atoms : Table A 49 Bond angles [] for 15 Bond Angle Bond Angle C23 W1 C21 83.04(11) C23 W1 O1 92.39( 9) C21 W1 O1 104.95(9) C23 W1 O2 89.20(9) C21 W1 O2 107.16(9) O1 W1 O2 147.80(7) C23 W1 N1 153.22(10) C21 W1 N1 123.66(10) O1 W1 N1 83.14(8) O2 W1 N1 81.16(7) C23 W1 C22 42.03(11) C21 W1 C22 41.01(10) O1 W1 C22 101.27(9) O2 W1 C22 101.29(8) N1 W1 C22 164.6 2(9) C1 O1 W1 128.81(15) C11 O2 W1 137.59(14) C13 N1 C3 117.82(19) C13 N1 W1 130.02(15) C3 N1 W1 111.98(15) O1 C1 C2 113.9(2) O1 C1 C8 104.8(2) C2 C1 C8 113.2(2) O1 C1 C9 107.9(2) C2 C1 C9 107.9(2) C8 C1 C9 108.9(2) C7 C2 C3 119.2(2) C7 C2 C1 121.9(2) C3 C 2 C1 118.8(2) C2 C3 C4 118.3(2) C2 C3 N1 122.7(2) C4 C3 N1 118.7(2) C5 C4 C3 121.0(2) C4 C5 C6 121.2(2) C7 C6 C5 117.9(2) C7 C6 C10 120.7(3) C5 C6 C10 121.3(2) C6 C7 C2 122.1(3) F2 C8 F1 106.7(2) F2 C8 F3 106.7(2) F1 C8 F3 108.2(2) F2 C8 C1 111.8(2) F1 C8 C1 110.7(2) F3 C8 C1 112.4(2) F4 C9 F6 107.0(2) F4 C9 F5 106.9(2) F6 C9 F5 106.9(2) F4 C9 C1 112.9(2) F6 C9 C1 110.8(2) F5 C9 C1 111.9(2) O2 C11 C12 112.54(19) O2 C11 C19 110.95(19) C12 C11 C19 108.54(19) O2 C11 C18 103.38(19) C12 C11 C18 112.90(19) C19 C1 1 C18 108.41(19) C17 C12 C13 119.1(2) C17 C12 C11 122.1(2) C13 C12 C11 118.7(2) C12 C13 C14 118.1(2) C12 C13 N1 122.0(2) C14 C13 N1 120.0(2) C15 C14 C13 121.6(2) C14 C15 C16 121.1(2) C15 C16 C17 117.5(2) C15 C16 C20 121.6(2) C17 C16 C20 120.8(2) C16 C17 C1 2 122.6(2) F8 C18 F7 106.8(2) F8 C18 F9 106.37(19) F7 C18 F9 107.2(2) F8 C18 C11 111.2(2) F7 C18 C11 110.6(2) F9 C18 C11 114.3(2) F11 C19 F12 107.6(2) F11 C19 F10 107.29(19) F12 C19 F10 106.39(19) F11 C19 C11 112.2(2) F12 C19 C11 110.62(19) F10 C19 C11 112 .4(2) C22 C21 C24 131.9(2) C22 C21 W1 78.64(15) C24 C21 W1 149.1(2) C21 C22 C23 119.9(2) C21 C22 C28 123.6(2) C23 C22 C28 116.5(2) C21 C22 W1 60.35(14) C23 C22 W1 59.54(13) C28 C22 W1 175.2(2) C22 C23 C33 127.0(2)

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352 Table A 5 1 Continued Bond Angle Bond Angle C22 C23 W1 78.44(15) C33 C23 W1 154.0(2) C21 C24 C27 107.5(2) C21 C24 C26 109.7(2) C27 C24 C26 108.6(2) C21 C24 C25 112.2(2) C27 C24 C25 108.6(2) C26 C24 C25 110.2(2) C22 C28 C29 111.4(2) C30' C29 C28 119.4(5) C30' C29 C30 33.1(4) C28 C29 C30 114.8(3) C31 C30 C29 115.3(4) C32 C31 C30 109.4(4) C29 C30' C31' 112.0(7) C30' C31' C32 111.1(5) C31 C32 C33 113.2(3) C31 C32 C31' 42.5(3) C33 C32 C31' 110.5(3) C23 C33 C32 113.3(3) Symmetry transformations used to generate equivalent atoms: Table A 50 Anisotropic displacement parameters ( 2 x 10 3 ) for 15 The anisotropic displacement factor exponent takes t he form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 W1 15(1) 11(1) 12(1) 1(1) 5(1) 1(1) F1 29(1) 26(1) 23(1) 8(1) 10(1) 6(1) F2 19(1) 26(1) 27(1) 3(1) 1(1) 1(1) F3 22(1) 22(1) 32(1) 1(1) 11(1) 8(1) F4 23(1) 28(1 ) 31(1) 4(1) 11(1) 12(1) F5 34(1) 23(1) 30(1) 7(1) 22(1) 5(1) F6 25(1) 24(1) 31(1) 12(1) 13(1) 4(1) F7 31(1) 12(1) 26(1) 1(1) 17(1) 1(1) F8 29(1) 17(1) 16(1) 0(1) 14(1) 6(1) F9 20(1) 20(1) 21(1) 1(1) 5(1) 8(1) F10 34(1) 25(1) 20(1) 4(1) 19(1) 8(1) F11 18(1) 21(1) 20(1) 0(1) 5(1) 3(1) F12 24(1) 10(1) 28(1) 2(1) 12(1) 0(1) O1 16(1) 14(1) 18(1) 5(1) 6(1) 0(1) O2 16(1) 14(1) 10(1) 1(1) 5(1) 3(1) N1 17(1) 10(1) 11(1) 2(1) 5(1) 2(1) C1 17(1) 12(1) 20(1) 1(1) 8(1) 2( 1) C2 18(1) 13(1) 17(1) 2(1) 10(1) 2(1) C3 18(1) 11(1) 12(1) 0(1) 9(1) 1(1) C4 17(1) 20(1) 16(1) 3(1) 8(1) 4(1) C5 25(2) 14(1) 17(1) 5(1) 13(1) 8(1) C6 30(2) 12(1) 24(1) 1(1) 18(1) 1(1) C7 22(1) 14(1) 23(2) 1(1) 13(1) 1(1) C8 19(1) 18( 1) 24(2) 2(1) 7(1) 2(1) C9 18(1) 15(1) 22(2) 2(1) 9(1) 2(1) C10 40(2) 12(1) 35(2) 1(1) 22(2) 1(1) C11 13(1) 10(1) 12(1) 1(1) 5(1) 0(1) C12 16(1) 9(1) 12(1) 0(1) 6(1) 3(1) C13 16(1) 10(1) 13(1) 2(1) 6(1) 4(1) C14 18(1) 16(1) 18(1) 4(1) 10(1) 4(1) C15 27(2) 18(1) 14(1) 3(1) 12(1) 5(1) C16 30(2) 11(1) 14(1) 1(1) 9(1) 4(1) C17 23(1) 8(1) 16(1) 1(1) 7(1) 1(1) C18 20(1) 14(1) 14(1) 0(1) 8(1) 2(1) C19 19(1) 14(1) 14(1) 1(1) 9(1) 1(1) C20 50(2) 20(2) 16(2) 4(1) 12(2) 5(1 )

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353 Table A 5 2 Continued. U 11 U 22 U 33 U 23 U 13 U 12 C21 21(1) 19(1) 14(1) 3(1) 8(1) 6(1) C22 17(1) 25(1) 13(1) 4(1) 4(1) 7(1) C23 15(1) 20(1) 18(1) 4(1) 6(1) 2(1) C24 26(2) 22(1) 19(2) 7(1) 11(1) 3(1) C25 35(2) 30(2) 28(2) 14(1) 14(2) 9(1) C26 30(2) 36(2) 26(2) 6(1) 15(1) 4(1) C27 37(2) 20(1) 28(2) 6(1) 19(2) 2(1) C28 28(2) 40(2) 14(1) 4(1) 4(1) 10(1) C29 32(2) 56(2) 23(2) 4(2) 4(1) 16(2) C32 40(2) 87(3) 31(2) 10(2) 14(2) 37(2) C33 38(2) 30(2) 39(2) 20(2) 24(2) 12(1) Figure A 174 Molecular Structure of 16 X Ray experimental : X Ray Intensity data were collected at 100 K on a Bruker SMART diffractometer using MoK radiation ( = 0.71073 ) and an APEXII CCD area detector. Raw data frames were read by program SAINT 1 and integrated using 3D profiling algorithms. The resulting data were reduced to produce hkl reflections and their intensities and estimated standard deviations. The data were corrected for Lorentz and polarization effects and numerical absorption corrections were applied based on

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354 indexed and measured faces. The structure was solved and refined in SHELXTL6.1, using full matrix least squares refinemen t. The non H atoms were refined with anisotropic thermal parameters and all of the H atoms were calculated in idealized positions and refined riding on their parent atoms. A disorder between H4a and a small percentage of Br on C4 was identified with the final refinement yielding 3% of Br and 97% of the proton. The Br atom was refined with several site occupation factors until an acceptable value was reached; which was 3%. In the final cycle of refinement, 5441 reflections (of which 4758 are observed wi th I > 2 (I)) were used to refine 403 parameters and the resulting R 1 wR 2 and S (goodness of fit) were 2.51 %, 4.76 % and 1.050 respectively. The refinement was carried out by minimizing the wR 2 function using F 2 rather than F values R 1 is calculated to provide a reference to the conventional R value but its function is not minimized. SHELXTL6 (2000). Bruker AXS, Madison, Wisconsin, USA. Table A 51 Crystal dat a and structure refinement for 16 Item Value Identification code orei2 4 Empirical formula C 27 H 26.94 Br 0.03 F 12 NO 3 W Formula weight 827.68 Temperature 100(2) K Wavelength 0.71073 Crystal system Triclinic Space group P 1 Unit cell dimensions a = 8.5483(3) = 86.891(2). b = 9.4574(3) = 82.183(2). c = 19.5076(6) = 70.699(2). Volume 1474.54(8) 3 Z 2 Density (calculated) 1.864 Mg/m 3 Absorption coefficient 4.064 mm 1 F(000) 806 Crystal size 0.14 x 0.12 x 0.08 mm 3 Theta range for data collection 1.05 to 25.48. Index ranges Reflections collected 28207 Independent reflections 5441 [R(int) = 0.0620] Completeness to theta = 25.48 99.1 % Absorption correction Numerical

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355 Table A 5 3 Continued Item Value Max. and min. transm ission 0.6607 and 0.5304 Refinement method Full matrix least squares on F 2 Data / restraints / parameters 5441 / 0 / 403 Goodness of fit on F 2 1.050 Final R indices [I>2sigma(I)] R1 = 0.0251, wR2 = 0.0476 [4758] R indices (all data) R1 = 0.0337, wR2 = 0.05 03 Largest diff. peak and hole 1.198 and 0.981 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants. Table A 52 Atomic coordinates ( x 10 4 ) and equi valent isotropic displacement parameters ( 2 x 10 3 ) for 16 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) W1 3609(1) 1736(1) 2549(1) 16(1) F1 5880(2) 4612(2) 2861(1) 30(1) F2 7688(2) 2958(2) 3406(1) 27(1) F 3 6058(2) 4965(2) 3925(1) 30(1) F4 6595(2) 982(2) 4222(1) 29(1) F5 5490(2) 2925(2) 4863(1) 31(1) F6 3976(2) 1660(2) 4595(1) 31(1) F7 1602(3) 3244(2) 8(1) 28(1) F8 2913(3) 1095(2) 423(1) 31(1) F9 4092(2) 2785(2) 270(1) 29(1) F10 894(2) 4073(2) 1021(1) 27(1 ) F11 17(3) 1759(2) 1329(1) 35(1) F12 415(2) 3500(2) 2066(1) 28(1) O1 5040(3) 2101(3) 3171(1) 19(1) O2 3011(3) 2015(3) 1620(1) 20(1) O3 5245(3) 24(3) 2314(1) 18(1) N1 2585(3) 3959(3) 2559(2) 17(1) Br 970(20) 5834(19) 2883(9) 50(4) C1 4814(4) 3133(4) 368 9(2) 18(1) C2 3058(4) 4308(4) 3776(2) 17(1) C3 2080(4) 4656(4) 3227(2) 17(1) C4 460(4) 5697(4) 3337(2) 20(1) C5 103(4) 6470(4) 3956(2) 22(1) C6 889(4) 6213(4) 4487(2) 19(1) C7 2446(4) 5116(4) 4387(2) 18(1) C8 6117(4) 3925(4) 3474(2) 20(1) C9 5219(4) 2179( 4) 4348(2) 22(1) C10 309(4) 7124(4) 5144(2) 24(1) C11 1969(4) 3106(4) 1228(2) 17(1) C12 2072(4) 4648(4) 1346(2) 17(1) C13 2442(4) 4975(4) 1990(2) 16(1) C14 2661(4) 6366(4) 2059(2) 21(1) C15 2447(4) 7408(4) 1526(2) 21(1) C16 2010(4) 7124(4) 898(2) 20(1) C17 1849(4) 5732(4) 826(2) 19(1) C18 2638(4) 2562(4) 475(2) 23(1)

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356 Table A 5 4 Continued. Atom X Y Z U(eq) C19 150(4) 3108(4) 1412(2) 21(1) C20 1761(5) 8246(4) 318(2) 27(1) C21 6921(4) 850(4) 1986(2) 23(1) C22 7123(5) 172(5) 1275(2) 42(1) C23 7040(5) 2471 (5) 1966(3) 48(1) C24 8137(4) 623(5) 2438(2) 35(1) C25 1954(4) 1209(4) 3141(2) 20(1) C26 1779(5) 170(4) 3514(2) 30(1) C27 3404(5) 1428(4) 3571(2) 34(1) Table A 53 Bond lengths [] for 16 Bond Length Bond Length W1 O3 1.819(2) W1 C25 1.882(4) W1 O2 1.931(2) W1 O1 1.953(2) W1 N1 1.993(3) F1 C8 1.337(4) F2 C8 1.345(4) F3 C8 1.339(4) F4 C9 1. 340(4) F5 C9 1.345(4) F6 C9 1.335(4) F7 C18 1.344(4) F8 C18 1.336(4) F9 C18 1.333(4) F10 C19 1.335(4) F11 C19 1.338(4) F12 C19 1.328(4) O1 C1 1.392(4) O2 C11 1.391(4) O3 C21 1.462(4) N1 C13 1.418(5) N1 C3 1.440(4) Br C4 1.571(16) C1 C8 1.539 (5) C1 C2 1.539(4) C1 C9 1.541(5) C2 C7 1.395(5) C2 C3 1.404(5) C3 C4 1.405(4) C4 C5 1.388(5) C5 C6 1.389(5) C6 C7 1.387(5) C6 C10 1.514(5) C11 C12 1.522(5) C11 C19 1.547(5) C11 C18 1.552(5) C12 C17 1.387(5) C12 C13 1.411(5) C13 C14 1.404(5) C14 C15 1.381(5) C15 C16 1.392(5) C16 C17 1.384(5) C16 C20 1.496(5) C21 C23 1.505(6) C21 C22 1.509(6) C21 C24 1.523(5) C25 C26 1.499(5) C26 C27 1.515(5) Symmetry transformations used to generate equivalent atoms: Table A 54 Bond angles [] for 16 Bond Angle Bond Angle O2 C11 C12 111.2(3) O2 C11 C19 109.6(3) C12 C11 C19 110.3(3) O2 C11 C18 103 .1(3) C12 C11 C18 112.4(3) C19 C11 C18 110.1(3) C17 C12 C13 119.1(3) C17 C12 C11 121.4(3) C13 C12 C11 119.5(3) C14 C13 C12 117.7(3) C14 C13 N1 120.0(3) C12 C13 N1 122.3(3) C15 C14 C13 121.3(3) C14 C15 C16 121.5(3) C17 C16 C15 116.8(3) C17 C16 C20 121.1(3) C15 C16 C20 122.1(3) C16 C17 C12 123.5(3) F9 C18 F8 106.8(3) F9 C18 F7 107.1(3) F8 C18 F7 106.3(3) F9 C18 C11 110.8(3) F8 C18 C11 111.3(3) F7 C18 C11 114.1(3)

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357 Table A 5 6 Continued Bond Angle Bond Angle F12 C19 F10 106.9(3) F12 C19 F11 107.5(3) F10 C19 F11 107.0(3) F12 C19 C11 110.9(3) F10 C19 C11 112.2(3) F11 C19 C11 112.0(3) O3 C21 C23 107.3(3) O3 C21 C22 107.0(3) C23 C21 C22 112. 9(3) O3 C21 C24 106.4(3) C23 C21 C24 111.6(3) C22 C21 C24 111.3(4) C26 C25 W1 137.2(3) C25 C26 C27 115.1(3) Symmetry transformations used to generate equivalent atoms: Table A 55 Anisotropic displacement parameters ( 2 x 10 3 ) for 16 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 W1 15(1) 16(1) 15(1) 1(1) 0(1) 2(1) F1 25(1) 39(1) 27(1) 10(1) 1(1) 13(1) F2 13(1) 34(1) 32(1) 5(1) 1(1) 4(1) F3 25(1) 32(1) 36(2) 12(1) 0(1) 13(1) F4 24(1) 28(1) 26(1) 3(1) 6(1) 4(1) F5 32(1) 38(1) 20(1) 2(1) 11(1) 4(1) F6 25(1) 37(1) 31(1) 14(1) 0(1) 12(1) F7 34(1) 34(1) 16(1) 0(1) 8(1) 9(1) F8 48(1) 22(1) 22(1) 6(1) 4(1) 10(1) F9 27(1) 36(1) 21(1) 6(1) 6(1) 9(1) F10 20(1) 34(1) 26(1) 5(1) 9(1) 8(1) F11 33(1) 28(1) 52(2) 0(1) 6(1) 19(1) F12 20(1) 41(1) 19(1) 1(1) 4(1) 10(1) O1 17(1) 20(1) 16(1) 4(1) 1(1) 0(1) O2 20(1) 18(1) 18(1) 3(1) 3(1) 2 (1) O3 18(1) 18(1) 14(1) 0(1) 2(1) 3(1) N1 18(1) 19(2) 11(2) 3(1) 4(1) 2(1) C1 15(2) 20(2) 18(2) 2(2) 0(2) 4(2) C2 13(2) 19(2) 16(2) 1(2) 0(2) 4(1) C3 18(2) 16(2) 16(2) 2(2) 0(2) 5(1) C4 21(2) 17(2) 20(2) 3(2) 3(2) 4(2) C5 16( 2) 23(2) 23(2) 2(2) 0(2) 2(2) C6 17(2) 20(2) 20(2) 4(2) 5(2) 8(2) C7 19(2) 23(2) 14(2) 1(2) 4(2) 10(2) C8 16(2) 24(2) 19(2) 0(2) 2(2) 5(2) C9 18(2) 26(2) 20(2) 0(2) 2(2) 4(2) C10 22(2) 27(2) 22(2) 6(2) 0(2) 6(2) C11 18(2) 17(2 ) 13(2) 3(2) 2(2) 4(2) C12 14(2) 20(2) 15(2) 0(2) 0(2) 6(1) C13 9(2) 18(2) 16(2) 2(2) 1(1) 0(1) C14 17(2) 21(2) 23(2) 7(2) 3(2) 4(2) C15 20(2) 16(2) 26(2) 1(2) 3(2) 5(2) C16 15(2) 22(2) 21(2) 4(2) 2(2) 5(2) C17 14(2) 25(2) 16(2 ) 0(2) 1(2) 6(2) C18 26(2) 24(2) 19(2) 1(2) 2(2) 9(2) C19 24(2) 20(2) 20(2) 0(2) 4(2) 10(2) C20 30(2) 25(2) 26(2) 5(2) 4(2) 10(2) C21 16(2) 26(2) 20(2) 6(2) 4(2) 2(2) C22 30(2) 60(3) 26(3) 2(2) 9(2) 5(2)

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358 Table A 5 7 Continued U 11 U 22 U 33 U 23 U 13 U 12 C23 31(2) 28(3) 77(4) 17(2) 4(2) 2(2) C24 20(2) 39(3) 38(3) 11(2) 3(2) 3(2) C25 21(2) 25(2) 10(2) 0(2) 3(2) 6(2) C26 31(2) 30(2) 27(3) 1(2) 7(2) 12(2) C27 46(2) 30(2) 31(3) 12(2) 5(2) 23(2) Figure A 175 Molecular Structure of 20 X Ray experimental : X Ray Intensity data were collected at 100 K on a Bruker DUO diffractometer using MoK radiation ( = 0.71073 ) and an APEXII CCD area detector. Raw data frames were read by program SAINT 1 and integrated using 3D profiling algorithms. The resulting data were reduced to produce hkl reflections and their intensities and estimated standard deviations. The data were corrected for Lorentz and polarization effects and numerical absorption corrections were applied based on indexed and measured faces. The structure was solved and refined in SHELXTL6.1, using full matrix least squares refinement. The non H atoms were refined with anisotropic thermal parameters and all of the H atoms were calculated in idealized

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359 positions and refined riding on their parent atoms. In the final cycle of refinement, 5714 reflections (of which 4559 are observed with I > 2 (I)) were used to refine 363 parameters and the resulting R 1 wR 2 and S (goodness of fit) were 1.87 %, 3.38 % and 0.901 respectively. The highest residual electron density peak is within 1 of W1 and thus attributed to its anisotropy. The refinemen t was carried out by minimizing the wR 2 function using F 2 rather than F values. R 1 is calculated to provide a reference to the conventional R value but its function is not minimized. SHELXTL6 (2008). Bruker AXS, Madison, Wisconsin, USA. Table A 56 Crystal data and structure refinement for 20 Item Value Identification code orei30 Empirical formula C 23 H 19 F 12 NO 3 W Formula weight 769.24 Temperature 100(2) K Wavelength 0.71073 Crystal system Monoclinic Space group P2 1 /c U nit cell dimensions a = 12.0588(6) = 90. b = 16.9746(9) = 112.895(1). c = 13.2038(7) = 90. Volume 2489.8(2) 3 Z 4 Density (calculated) 2.052 Mg/m 3 Absorption coefficient 4.757 mm 1 F(000) 1480 Crystal size 0.09 x 0.04 x 0.02 mm 3 Theta range for data collection 1.83 to 27.50. Index ranges Reflections collected 45799 Independent reflections 5714 [R(int) = 0.0472] Completeness to theta = 25.48 100.0 % Absorption correction Numerical Max. and min. transmission 0.91 93 and 0.6660 Refinement method Full matrix least squares on F 2 Data / restraints / parameters 5714 / 0 / 363 Goodness of fit on F 2 0.901 Final R indices [I>2sigma(I)] R1 = 0.0187, wR2 = 0.0338 [4559] R indices (all data) R1 = 0.0300, wR2 = 0.0352 Largest diff. peak and hole 1.581 and 0.643 e. 3 R1 = (||F o | |F c ||) / |F o | wR2 = [ w(F o 2 F c 2 ) 2 ] / w F o 2 2 ]] 1/2 S = [ w(F o 2 F c 2 ) 2 ] / (n p)] 1/2 w= 1/[ 2 (F o 2 )+(m*p) 2 +n*p], p = [max(F o 2 ,0)+ 2* F c 2 ]/3, m & n are constants.

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360 Table A 57 Atomic coordinates ( x 10 4 ) a nd equivalent isotropic displacement parameters ( 2 x 10 3 ) for 20 U(eq) is defined as one third of the trace of the orthogonalized U ij tensor. Atom X Y Z U(eq) W1 480(1) 3415(1) 5351(1) 13(1) F1 589(1) 2776(1) 7359(1) 24(1) F2 2463(1) 2603(1) 7013(1) 30(1) F3 1757(2) 3775(1) 7087(1) 30(1) F4 3435(1) 3292(1) 3771(1) 23(1) F5 3028(1) 4199(1) 4992(1) 20(1) F6 4058(1) 3193(1) 5091(1) 24(1) F7 4190(1) 3026(1) 7507(1) 29(1) F8 4996(1) 2374(1) 6565(1) 29(1) F9 4234(1) 3521(1) 6027(1) 25(1) F10 1699(2) 192 1(1) 4099(1) 32(1) F11 3487(2) 1470(1) 4926(1) 31(1) F12 3223(2) 2618(1) 4189(1) 30(1) O1 1079(1) 3459(1) 5339(1) 15(1) O2 2042(2) 3116(1) 5534(2) 16(1) O3 132(2) 3908(1) 4142(2) 21(1) N1 303(2) 2258(1) 5623(2) 14(1) C1 1942(2) 2999(2) 5524(2) 13(1) C2 1897(2) 2152(2) 5159(2) 13(1) C3 816(2) 1836(2) 5179(2) 13(1) C4 839(2) 1080(2) 4763(2) 16(1) C5 1874(2) 633(2) 4403(2) 17(1) C6 2942(2) 923(2) 4425(2) 16(1) C7 2935(2) 1690(2) 4796(2) 16(1) C8 1692(2) 3038(2) 6761(2) 19(1) C9 3139(2) 3419(2) 4833(2 ) 18(1) C10 4086(2) 445(2) 4046(2) 22(1) C11 2834(2) 2479(2) 5827(2) 14(1) C12 2473(2) 1868(1) 6485(2) 11(1) C13 1275(2) 1804(1) 6384(2) 12(1) C14 1031(2) 1279(2) 7091(2) 15(1) C15 1904(2) 801(2) 7803(2) 14(1) C16 3081(2) 821(2) 7858(2) 13(1) C17 3344(2) 1364(1) 7202(2) 13(1) C18 4085(2) 2853(2) 6494(2) 20(1) C19 2818(3) 2122(2) 4746(2) 21(1) C20 4035(2) 288(2) 8616(2) 20(1) C21 1128(2) 4226(2) 6656(2) 19(1) C22 2203(3) 4744(2) 6772(3) 30(1) C23 2564(3) 5280(2) 7769(2) 32(1) Table A 60 Bond lengths [] for 20 Bond Length Bond Length W1 O3 1.7040(18) W1 O2 1.8737(16) W1 O1 1.8753(16) W1 N1 2.022(2) W1 C21 2.105(3) F1 C8 1 .332(3) F2 C8 1.327(3) F3 C8 1.334(3) F4 C9 1.323(3) F5 C9 1.340(3) F6 C9 1.336(3) F7 C18 1.326(3) F8 C18 1.340(3) F9 C18 1.336(3)

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361 Table A 60 Continued Bond Length B ond Length F10 C19 1.330(3) F11 C19 1.335(3) F12 C19 1.330(3) O1 C1 1.397(3) O2 C11 1.394(3) N1 C3 1.435(3) N1 C13 1.437(3) C1 C2 1.524(3) C1 C8 1.543(3) C1 C9 1.549(3) C2 C7 1.395(3) C2 C3 1.400(3 ) C3 C4 1.393(4) C4 C5 1.378(4) C5 C6 1.390(4) C6 C7 1.390(4) C6 C10 1.508(3) C11 C12 1.521(3) C11 C19 1.543(4) C11 C18 1.556(4) C12 C17 1.399(3) C12 C13 1.402(3) C13 C14 1.402(3) C14 C15 1.371(3) C15 C16 1.394(3) C16 C17 1.383(3) C16 C20 1. 499(3) C21 C22 1.523(4) C22 C23 1.518(4) Symmetry transformations used to generate equivalent atoms: Table A 58 Bond angles [] for 20 Bond Angle Bond Angle O3 W1 O2 97.06(8) O3 W1 O1 95.23(8) O2 W1 O1 165.07(8) O3 W1 N1 129.69(9) O2 W1 N1 83.37(8) O1 W1 N1 82.27(8) O3 W1 C21 108.82(10) O2 W1 C21 92.15(9) O1 W1 C21 91.87(9) N1 W1 C21 121.46(9) C1 O1 W 1 142.07(16) C11 O2 W1 142.37(16) C3 N1 C13 113.55(19) C3 N1 W1 124.01(15) C13 N1 W1 122.11(15) O1 C1 C2 110.6(2) O1 C1 C8 108.0(2) C2 C1 C8 111.1(2) O1 C1 C9 103.1(2) C2 C1 C9 112.8(2) C8 C1 C9 110.9(2) C7 C2 C3 119.8(2) C7 C2 C1 120.1(2) C3 C2 C1 120.2(2 ) C4 C3 C2 118.0(2) C4 C3 N1 119.5(2) C2 C3 N1 122.5(2) C5 C4 C3 121.3(2) C4 C5 C6 121.3(2) C7 C6 C5 117.5(2) C7 C6 C10 120.0(2) C5 C6 C10 122.5(2) C6 C7 C2 121.9(2) F2 C8 F1 107.5(2) F2 C8 F3 107.9(2) F1 C8 F3 107.0(2) F2 C8 C1 111.9(2) F1 C8 C1 110.5(2) F3 C8 C1 111.7(2) F4 C9 F6 108.4(2) F4 C9 F5 107.2(2) F6 C9 F5 106.6(2) F4 C9 C1 110.8(2) F6 C9 C1 113.1(2) F5 C9 C1 110.5(2) O2 C11 C12 111.7(2) O2 C11 C19 106.7(2) C12 C11 C19 110.9(2) O2 C11 C18 104.4(2) C12 C11 C18 112.6(2) C19 C11 C18 110.2(2) C17 C12 C13 119.4(2) C17 C12 C11 119.8(2) C13 C12 C11 120.8(2) C14 C13 C12 117.5(2) C14 C13 N1 118.8(2) C12 C13 N1 123.7(2) C15 C14 C13 121.9(2) C14 C15 C16 121.1(2) C17 C16 C15 117.4(2) C17 C16 C20 121.1(2) C15 C16 C20 121.4(2) C16 C17 C12 122.5(2) F7 C18 F9 107 .5(2) F7 C18 F8 108.1(2) F9 C18 F8 107.0(2) F7 C18 C11 110.7(2) F9 C18 C11 111.1(2)

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362 Table A 6 1 Continued Bond Angle Bond Angle F 8 C18 C11 112.3(2) F10 C19 F12 107.8(2) F10 C19 F11 107.1(2) F12 C19 F11 107.2(2) F10 C19 C11 109.9(2) F12 C19 C11 112.8(2) F11 C19 C11 111.8(2) C22 C21 W1 119.37(19) C23 C22 C21 112.2(2) Symmetry transformations used to generate equivalent atoms: Table A 59 Anisotropic displacement parameters ( 2 x 10 3 ) for 20 The anisotropic displacement factor exponent takes the form: 2 2 [ h 2 a* 2 U 11 + ... + 2 h k a* b* U 12 ] U 11 U 22 U 33 U 23 U 13 U 12 W1 11(1) 13(1) 16(1) 3(1) 6(1) 2(1) F1 20(1) 32(1) 16(1) 0(1) 2(1) 6(1) F2 28(1) 45(1) 23(1) 3(1) 15(1) 5(1) F3 42(1) 26(1) 22(1) 7(1) 10(1) 9(1) F4 23(1) 26(1) 17(1) 1(1) 3(1) 7(1) F5 18(1) 14(1) 29(1) 1(1) 9(1) 5(1) F6 12(1) 25(1) 37(1) 4(1) 12(1) 2(1) F7 30(1) 3 3(1) 22(1) 4(1) 7(1) 15(1) F8 12(1) 30(1) 45(1) 17(1) 11(1) 4(1) F9 18(1) 20(1) 38(1) 10(1) 13(1) 3(1) F10 30(1) 44(1) 18(1) 8(1) 5(1) 2(1) F11 48(1) 24(1) 29(1) 6(1) 24(1) 19(1) F12 42(1) 33(1) 27(1) 12(1) 25(1) 9(1) O1 12(1) 13(1) 24(1) 1(1) 9(1) 0(1) O2 13(1) 12(1) 26(1) 4(1) 10(1) 4(1) O3 20(1) 26(1) 20(1) 8(1) 11(1) 6(1) N1 8(1) 14(1) 17(1) 1(1) 3(1) 2(1) C1 10(1) 13(1) 16(1) 0(1) 6(1) 0(1) C2 13(1) 14(1) 12(1) 2(1) 6(1) 2(1) C3 14(1) 13(1) 12(1) 4(1) 4(1) 1( 1) C4 14(1) 18(2) 16(1) 0(1) 5(1) 6(1) C5 23(1) 13(1) 15(1) 3(1) 6(1) 0(1) C6 15(1) 17(2) 14(1) 2(1) 3(1) 1(1) C7 12(1) 20(2) 17(1) 1(1) 5(1) 2(1) C8 17(1) 22(2) 18(1) 1(1) 7(1) 2(1) C9 14(1) 18(1) 22(1) 1(1) 8(1) 1(1) C10 18(1) 18(2 ) 27(2) 1(1) 4(1) 2(1) C11 10(1) 15(1) 15(1) 3(1) 5(1) 3(1) C12 13(1) 12(1) 10(1) 1(1) 6(1) 1(1) C13 14(1) 9(1) 12(1) 3(1) 4(1) 2(1) C14 13(1) 16(1) 18(1) 3(1) 8(1) 2(1) C15 18(1) 12(1) 14(1) 1(1) 6(1) 3(1) C16 15(1) 11(1) 12(1) 2(1) 3(1) 1(1) C17 11(1) 15(2) 13(1) 2(1) 4(1) 1(1) C18 17(1) 19(2) 24(2) 9(1) 9(1) 1(1) C19 24(2) 21(2) 20(2) 6(1) 12(1) 7(1) C20 16(1) 18(2) 21(1) 7(1) 3(1) 0(1) C21 17(1) 18(2) 21(1) 0(1) 6(1) 1(1) C22 27(2) 27(2) 39(2) 12(2) 16( 1) 6(1) C23 27(2) 26(2) 35(2) 3(1) 3(1) 4(1)

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363 A.8 DFT Calculations Spin restricted density functional theory calculations of complex es were executed in the Gaussian 03 program suite. Calculations employed geometry optimization and single point a nalysis using hybrid functional (the three parameter exchange functional of Becke (B3) and the correlation functional of Lee, Yang, and Parr (LYP) (B3LYP). Full geometry optimization and single point analysis for the complexes were performed using the LAN L2DZ basis set. The atomic coordinates were generated from Gabedit 2.3.0. Molecular orbital pictures were generated from Gabedit with isovalues of 0.051687au. Table A 60 Atomic coordinates for the geometry optimized structure of 12 Atom x y z W 0.12745 1.08614 0.29451 F 3.90526 0.90583 0.469071 F 3.89004 1.65156 1.63545 F 5.011239 0.215578 1.1324 F 3.003304 0.209846 3.55598 F 3.574594 2.107173 2.50412 F 1.414422 1.638585 2.87029 F 4.09731 0.59176 2.27099 F 4.4724 2.0963 0.66299 F 5.57796 0.15717 0.63626 F 3.76437 1.40866 1.939733 F 4.57599 0.677311 1.760095 F 2.40456 0.35175 2.209716 O 1.489991 0.63172 1.32539 O 2.08324 1.02917 0.32489 O 0.26758 3.02829 1.18753 N 0.27874 0.929631 0.09915 C 2.505278 0.325479 1.13454 C 2.202208 1.357805 0.02189 C 0.870699 1.627367 0.409017 C 0.682353 2.610386 1.411257 C 1.752625 3.319335 1.959522 C 3.075933 3.07615 1.526012 C 3.270606 2.0968 0.5 38379 C 3.827622 0.49244 0.86357 C 2.638493 1.067798 2.51625 C 4.246489 3.835739 2.120942 C 3.12363 0.11955 0.08009 C 2.74293 1.303936 0.53261 C 1.3743 1.721334 0.56289 C 1.11454 3.021981 1.07857

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364 Table A 6 3 Continued. Atom x y z C 2.13595 3.886204 1.47445 C 3.49155 3.503415 1.38033 C 3.76042 2.206795 0.91517 C 4.32694 0.72742 0.89733 C 3.47545 0.13136 1.453772 C 4.60795 4.447572 1.78421 C 0.477852 1.49288 1.320329 C 0.810842 1.78321 2.758397 C 0.969409 0.44128 3.531436 C 2.137885 2.59177 2.850495 C 0.34777 2.61029 3.391829 C 0.514105 4.23663 0.7693 C 1.657527 4.51633 1.74263 C 1.24338 3.254 2.31383 C 1.02881 2.23553 3.43098 H 0.33007 2.798816 1.7548 H 1.564255 4.0 61468 2.733014 H 4.28429 1.917495 0.195396 H 4.408044 3.558148 3.172053 H 4.073122 4.919538 2.094698 H 5.175428 3.631356 1.57737 H 0.08397 3.34462 1.17103 H 1.87686 4.868363 1.86581 H 4.79759 1.897084 0.8491 H 4.63989 5.330939 1.131 17 H 5.5868 3.958459 1.72818 H 4.47304 4.809397 2.81252 H 1.191039 0.64969 4.58748 H 0.048463 0.149618 3.479676 H 1.787505 0.158363 3.11689 H 2.382211 2.78883 3.903643 H 2.967245 2.04043 2.396648 H 2.049407 3.56033 2.339518 Table A 61 Atomic coordinates for the geometry optimized structure of 13 Atom x y z W 0.081727 0.769395 0.07934 N 0.02057 1.16183 0.48527 C 2.751792 1.57054 1.739777 F 3.97651 1.00195 2.95987 F 3.15943 1.05971 3.29416 F 1.76755 0.69728 3.20096 F 3.131144 0.73439 2.792038 C 1.24657 1.865 0.18993 F 3.91091 2.176779 0.85321 C 3.57092 3.41165 0.468937 F 3.562631 2.70654 1.808228 C 1.14234 3.14676 0.412189 F 3.91738 0. 801235 0.907942 C 2.27017 3.90349 0.728253 C 2.54961 1.35104 0.42981 F 5.20535 0.356503 0.88322 C 2.72753 0.02727 1.08443

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365 Table A 6 4 Continued. Atom x y z F 1.448012 1.99586 2.027041 C 0.652071 2.79482 2.19109 C 3.68037 2. 13633 0.10499 C 3.325289 2.66974 1.42081 C 1.601736 3.59412 2.83142 C 2.91846 0.14265 2.63582 C 2.381576 1.84629 0.77015 C 3.94451 0.835991 0.49476 C 1.010446 1.91974 1.13597 O 1.61688 0.876496 0.91842 F 4.372839 0.222578 1 .19057 F 4.501695 0.802052 0.964387 O 1.980816 0.27248 0.347245 F 5.285809 1.18447 0.308717 C 0.08731 2.769919 1.041259 C 0.173097 4.152301 1.664814 C 0.86703 1.404378 3.196218 C 1.38509 0.05417 3.343128 C 1.119601 3.559784 1.28426 C 0.506963 4.817254 1.52482 C 1.051822 5.706276 2.46566 C 2.8278 4.110827 2.9522 C 2.282698 3.213804 2.02042 C 0.39366 1.593961 1.766174 C 2.961803 3.55386 2.45065 C 0.558234 2.585918 0.35977 C 2.800822 0.86333 0.334078 C 4.24178 0 .26538 0.113867 C 3.997313 4.41408 3.14946 C 4.79981 4.23206 0.810008 C 0.321257 1.603497 4.186459 C 2.03134 2.378606 3.54083 C 2.216348 5.360327 3.17895 H 0.15264 3.53419 0.627441 H 2.14384 4.88248 1.186479 H 0.38635 2.83394 2 .50157 H 4.67315 1.75363 0.31517 H 4.36685 2.6324 1.12137 H 1.286702 4.25179 3.63914 H 0.78793 4.669147 1.542443 H 0.945925 4.750263 1.175306 H 0.387247 4.088999 2.732777 H 0.59535 0.77912 3.113435 H 2.23389 0.24089 2.675342 H 1.71714 0.22834 4.375005 H 0.41088 5.080287 1.00553 H 0.565057 6.661093 2.64886

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366 Table A 62 Atomic coordinates for the geometry optimized structure of [CF 3 ONO]W N(OEt 2 ). Atom x y z W 0.01166 1.316234 0.600527 F 3.913603 1.229893 1.515286 F 4.030253 2.296927 0.443369 F 5.198502 0.414432 0.140982 F 3.33012 0.778441 2.697482 F 3.946094 1.246314 1.954514 F 1.785035 0.813 864 2.364152 F 3.796878 1.182565 1.617204 F 4.302323 2.329171 0.230359 F 5.366653 0.413771 0.199896 F 3.891514 1.030603 2.662688 F 4.463343 1.025995 1.968994 F 2.373435 0.622244 2.679057 O 1.664664 1.160067 0.450622 O 1.942803 1. 241175 0.592126 O 0.186861 3.391454 0.17621 N 0.083467 0.667241 0.393897 C 2.713813 0.216503 0.368715 C 2.402922 1.011125 0.527336 C 1.069872 1.404678 0.840574 C 0.872706 2.542169 1.655963 C 1.949557 3.293276 2.132914 C 3.276 638 2.933096 1.809896 C 3.474692 1.797202 1.00604 C 3.96657 1.030831 0.138139 C 2.959677 0.261459 1.845638 C 4.454314 3.724858 2.34463 C 2.959918 0.279118 0.495816 C 2.50035 0.996421 0.242675 C 1.123777 1.379105 0.28121 C 0.79095 3 2.545441 1.020217 C 1.762716 3.328622 1.644984 C 3.130519 2.989386 1.565018 C 3.466005 1.820263 0.862885 C 4.116227 1.037804 0.260229 C 3.431845 0.07891 1.95439 C 4.19323 3.844268 2.228102 N 0.592797 1.428933 2.194471 C 0.43554 4.4 74798 1.021901 C 1.663433 5.057921 0.328612 C 1.093684 3.8766 0.923597 C 0.858324 3.074619 2.200824 H 0.145332 2.816337 1.914712 H 1.762295 4.158219 2.765696 H 4.494021 1.526383 0.753022 H 4.668874 3.453191 3.388017 H 4.254049 4.803205 2.323259 H 5.363305 3.537462 1.762241 H 0.252695 2.826533 1.101529 H 1.455409 4.210883 2.203073 H 4.514657 1.552057 0.797687 H 4.175274 4.87233 1.84169

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367 Table A 6 5 Continued Atom x y z H 5.197335 3.441329 2.056621 H 4.03 7471 3.902994 3.314008 H 0.351234 5.216807 1.202695 H 0.688029 3.971781 1.956629 H 2.125404 5.802596 0.990257 H 2.399306 4.274613 0.123699 H 1.408341 5.558547 0.613281 H 0.857782 4.934655 1.069911 H 2.112562 3.764881 0.540445 H 1.481769 3.494621 3.000402 H 0.190227 3.120197 2.512224 H 1.155383 2.026312 2.086853

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368 Figure A 176 Truncated molecular orbital diagram of [CF 3 ONO]W N(OEt 2 ).

PAGE 369

369 Figure A 177 Labeling Scheme of the geometry optimization structure for 16 Figure A 178 Guassian optimized IR spectrum for 16 Table A 63 Atomic coordinates of the geometry optimization calculation for 16 Atom x y z W1 0.0409 1.0611 0.2816 O3 0.0307 2.8045 0.2955 O2 1.9879 0.9337 0.1985 O1 1.6624 0.7544 0.6847 N1 0.2099 0.9 342 0.0761 F9 4.118 0.8952 1.6468 F8 4.4186 2.0004 0.2741 F7 5.4852 0.067 0.0667 F6 3.7799 0.7689 1.3622 F5 5.1488 0.1355 0.1766 F4 4.0975 1.7899 0.6015

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370 Table A 6 6 Continued. Atom x y z F3 3.9524 1.6741 2.133 1 F2 3.3662 0.3547 2.8888 F12 2.1509 0.9511 2.4232 F11 3.5306 0.8041 2.6137 F10 4.3423 1.2102 2.0389 F1 1.807 1.2346 2.6162 C9 3.9294 0.5425 0.0107 C8 2.9638 0.686 2.0551 C7 3.2803 2.2873 0.7953 C6 2.9816 3.4071 1.5874 C5 1.62 09 3.6704 1.8642 C4 0.6155 2.8509 1.3477 C3 0.9137 1.7334 0.5274 C27 1.2944 4.5194 1.369 C26 1.1393 4.9189 0.6738 C25 0.6006 3.3298 2.5999 C24 0.1215 3.9238 1.2593 C23 1.3996 3.5024 2.5443 C22 1.0725 2.0968 3.0829 C21 0.4793 1.095 2.1067 C20 4.423 4.1175 2.3745 C2 2.2782 1.4362 0.2743 C19 3.2703 0.3318 1.8515 C18 4.2645 0.729 0.2681 C17 3.6455 2.1055 1.0224 C16 3.3323 3.2537 1.7715 C15 1.9676 3.5711 1.9395 C14 0.9691 2.7954 1.3435 C13 1.2804 1 .6628 0.5517 C12 2.6516 1.3015 0.4287 C11 3.0139 0.0162 0.3299 C10 4.0785 4.2936 2.1447 C1 2.6736 0.2206 0.5831 Figure A 179 Labelling Scheme of the geometry optimization calc ulation for 16

PAGE 371

371 Figure A 180 Guassian optimizated IR spectrum calculation for 16 Table A 64 Atomic coordinates of the geometry optimization calculation for 16 Atom x y z W1 0.2132 0.94 0.191 O3 0.4645 2.8454 0.7416 O2 2.0871 0.812 0.2758 O1 1.4882 0.8203 0.6099 N1 0.2258 1.0408 0.1267 F9 5.5042 0.0203 0.5445 F8 4.4196 1.9084 0.1519 F7 3.905 0.6952 1.9653 F6 4.8618 0. 1926 1.3608 F5 3.7903 1.7678 1.313 F4 4.1503 0.678 0.5982 F3 2.9253 1.7887 2.7146 F2 2.6108 0.3708 3.2767 F12 4.601 1.4049 1.6655 F11 4.0614 0.6939 2.2912 F10 2.5127 0.9253 2.3824 F1 0.8665 0.8725 2.6328 C9 3.8191 0.5045 0 .7501 C8 2.2244 0.6304 2.3968 C7 3.3538 2.2314 0.4212 C6 3.2279 3.3229 1.2963 C5 1.9511 3.604 1.8196 C4 0.8344 2.84 1.4423 C3 0.957 1.7622 0.5441 C28 1.2399 2.7338 2.018 C27 1.1663 5.2423 0.5001 C26 1.1318 4.6159 1.4807 C25 0.6346 4.3089 0.9755 C24 0.0559 4.3212 0.4351 C23 1.866 0.3669 3.7238 C22 1.6371 1.4238 2.6793 C21 0.3095 1.2522 1.9865 C20 4.3248 4.4022 2.3371 C2 2.2495 1.4299 0.0508

PAGE 372

372 Table A 6 7 Continued. Atom x y z C1 9 3.6034 0.4451 1.638 C18 4.263 0.605 0.6183 C17 3.6208 2.2774 1.0806 C16 3.2808 3.4847 1.7271 C15 1.918 3.8103 1.7951 C14 0.9403 2.9953 1.2056 C13 1.2721 1.8001 0.5248 C12 2.6516 1.4303 0.5025 C11 3.1352 0.1461 0.1743 C10 4.4356 4.1715 1.6573 C1 2.4314 0.222 0.8944 Figure A 181 Labeling Scheme of the geometry optimization calculation for 17 Figure A 182 Guassian optimizated IR spectrum calculation for 17

PAGE 373

373 Table A 65 Atomic coordinates of the geometry optimization calculation for 17 Atom x y z W1 0.0531 1.1305 0.2795 O3 0.0821 2.8351 1.1551 O 2 2.0414 1.0396 0.2245 O1 1.6124 0.5411 1.2181 N1 0.2997 0.9962 0.2244 F9 4.3016 0.8284 1.9721 F8 4.4452 2.1516 0.1783 F7 5.5682 0.2261 0.219 F6 3.7794 0.7943 0.8809 F5 5.0841 0.3389 0.552 F4 4.069 1.5388 1.2041 F3 3.8482 2.1839 2.1446 F2 3.4055 0.286 3.2481 F12 2.1401 0.5929 2.1972 F11 3.5559 1.1408 2.2412 F10 4.3281 0.9362 1.8895 F1 1.7545 1.7344 2.7938 C9 3.869 0.3845 0.4527 C8 2.9031 1.1462 2.2657 C7 3.1266 2.2282 0.8159 C6 2.8042 3.2 469 1.7236 C5 1.432 3.5103 1.9461 C4 0.4477 2.781 1.2809 C3 0.7605 1.7432 0.3548 C27 0.5838 4.8224 0.1644 C26 0.2116 4.9109 2.3521 C25 1.7423 4.406 0.7982 C24 0.2222 4.2559 1.0245 C23 1.8541 2.6531 3.1181 C22 0.8456 1.5094 2. 8312 C21 0.4785 1.3619 1.3917 C20 4.7628 4.1589 2.2048 C2 2.1442 1.4713 0.1335 C19 3.2684 0.059 1.5782 C18 4.3349 0.8219 0.5761 C17 3.8213 2.0655 1.0953 C16 3.6079 3.3198 1.6871 C15 2.2693 3.7604 1.8038 C14 1.2136 2.983 1.3 309 C13 1.4144 1.7159 0.7017 C12 2.7674 1.2547 0.6165 C11 3.0538 0.1171 0.0219 C10 3.883 4.0309 2.45 C1 2.5811 0.4177 0.9053

PAGE 374

374 Figure A 183 Labeling Scheme of the geometry optimization calculation for 21 Figure A 184 Guassian optimizated IR spectrum calculation for 21

PAGE 375

375 Table A 66 Atomic coordinates of the geometry optimization calcula tion for 21 Atom x y z W1 0.0187 0.1921 0.431 O3 0.0207 1.778 0.2805 O2 1.9643 0.1041 0.1867 O1 1.9629 0.0791 0.0219 N1 0.0383 2.1264 0.3166 F9 3.027 1.7553 1.9033 F8 5.0498 0.8345 1.7163 F7 3. 3159 0.4184 2.3746 F6 3.5951 1.2859 1.9272 F5 3.2951 2.5854 0.1201 F4 5.2639 1.5845 0.4668 F3 3.0533 1.3346 2.3643 F2 3.3314 0.8829 2.4415 F12 5.2641 1.5091 0.9152 F11 3.5861 0.9737 2.2984 F10 3.3011 2.5656 0.7473 F1 5.0688 0.4508 1.9887 C9 3.8658 1.3957 0.5684 C8 3.6917 0.2647 1.7345 C7 5.4171 1.3535 0.3341 C6 5.9739 2.5109 0.9077 C5 5.1478 3.4623 1.5354 C4 3.7573 3.2497 1.58 C36 0.2408 1.2472 2.6152 C35 0.0184 1.3171 3.994 C34 0.7361 2.3966 4.5405 C33 1.1948 3.4097 3.6726 C32 0.95 3.3417 2.294 C31 0.2278 2.2542 1.7285 C30 0.6608 3.5718 1.6094 C3 3.1946 2.0963 1.0044 C29 0.5173 4.7649 2.3391 C28 0.358 7 5.7776 1.9013 C27 1.089 5.5737 0.7127 C26 0.9484 4.3829 0.0177 C25 0.0754 3.3533 0.4212 C24 0.1252 4.1812 0.1095 C23 1.3466 2.9726 1.9837 C22 1.1728 3.083 1.9895 C21 0.0827 2.9911 1.0949 C20 0.23 0.7625 3.6213 C2 4.0219 1.142 0.3818 C19 0.1333 0.5225 2.1569 C18 3.8667 1.315 0.9743 C17 3.673 0.5987 1.4852 C16 5.4364 1.3509 0.2117 C15 6.0226 2.5565 0.6382 C14 5.2385 3.5526 1.2501 C13 3.8588 3.337 1.4238 C12 3.2669 2.1371 0.9909 C11 4.0515 1.1372 0.3856 C10 3.3331 0.1896 0.0018 C1 3.329 0.1241 0.2037

PAGE 376

376 Figure A 185 Molecular Orbital Diagram of 16 containing LUMO HOMO( 5). (Isovalue = 0.051687)

PAGE 377

377 Figure A 186 Molecular Orbital Diagram of 17 containing LUMO HOMO( 5). (Isovalue = 0.051687)

PAGE 378

378 Figure A 187 Molecular Orbital Diagram of 21 containing LUMO HOMO( 5). (Isovalue = 0.051687)

PAGE 379

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401 BIOGRAPHICAL SKETCH and Ann His family moved to Greenville, NY. There, he atten ded Hosanna Christian Academy unt ll 8 th grade homeschooled in 9 th grade, and then finally attend ed Greenville Central High School. Upon graduating fr om high school, he received the August C. Stiefel science award. For his university studies, he attended SUNY Albany for a year before transferring to Lee University in Cleveland, TN. As an adolescent, Matthew had an affinity for science and cooking, thus he pursued chemistry as his major. He participated in two Research for Undergraduates Experiences at North Carolina State University and Universit Lou is Pasteur during his undergraduate studies. Upon graduting from Lee, Matthew received the Lee University Chemistry Department Award. Thereafter he attend ed the University of Florida for his graduate studies. During that time, he received the Eastman Chemi cal Fellowship and was a selected participant to the 2013 Lindau Meeting. He received his Ph.D. fro m the University of Florida in August 2013