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 Title Page
 Table of Contents
 List of Tables
 Acknowledgement
 Introduction
 Discussion
 Experimental
 Summary
 Bibliography
 Biographical notes






Group Title: synthesis and reactions of fluorine-containing organo-silicon compounds
Title: The Synthesis and reactions of fluorine-containing organo-silicon compounds
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Title: The Synthesis and reactions of fluorine-containing organo-silicon compounds
Physical Description: iv, 48 l. : illus. ; 28 cm.
Language: English
Creator: Tomasino, Charles, 1931-
Publication Date: 1959
Copyright Date: 1959
 Subjects
Subject: Organosilicon compounds   ( lcsh )
Chemistry thesis Ph. D
Dissertations, Academic -- Chemistry -- UF
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
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Thesis: Thesis--University of Florida.
Bibliography: Bibliography: l. 48.
Additional Physical Form: Also available on World Wide Web
General Note: Manuscript copy.
General Note: Vita.
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Bibliographic ID: UF00098004
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
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Resource Identifier: alephbibnum - 000423892
oclc - 11023396
notis - ACH2297

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Table of Contents
    Title Page
        Page i
    Table of Contents
        Page ii
    List of Tables
        Page iii
    Acknowledgement
        Page iv
    Introduction
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
    Discussion
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
    Experimental
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
    Summary
        Page 46
        Page 47
    Bibliography
        Page 48
    Biographical notes
        Page 49
        Page 50
Full Text











The Synthesis and Reactions of Fluorine-Containing

Organo-Silicon Compounds












By
CHARLES TOMASINO


A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY











UNIVERSITY OF FLORIDA
January, 1959














TABLE OF COTENrTS


LIST OF TABLES . . . . . .


ACKOLEDGEEfTS . . . . . .


ITODUCTIO . . . . . .


DISCUSSIOI . . . . . . .


EXPERIIEIAL . . . . . . .

General Considerations . . .


A. Additions of 1,2-Dlbromo-2-chloro-I


trifluoroethane to Alkenyl Silicon


B. Reactions of the Addition Products


C. rllscellaneous Reactions . . .


D. Preparation of Starting Materials

SUfIARY .. . . . . . .


DIOLIOGRAPHY . . . . . .


BIOGRAPHICAL NOTES . .. . .


Page


* IV


Compounds, .... 27


. . . . 33


. . . . 42


. . . . . 43

. . . ... 46


..... . 48


. . . . . 49
0 JiJ



L9


i.
II.






















IV.


V.


...


..










r


* .

. .

















LIST OF TABLES


Table .. Page

I. Properties of the Compounds Prepared . . . . 22-23


2. Analyses of the Compounds Prepared .... . 24


-IIl-
















ACKNOWLEDGE-ENTS


The author wishes to express his appreciation to these whose

assistance, advice and encouragement have contributed greatly to the

success of this research: to Dr. Paul Tarrant, director of this research

and Chairman of the Supervisory Comlttee, whose creative Ideas, Inspira-

tion, and assistance have been the essential factors In the success of

this work; to the Office of the Quartermaster General, U. S. Army,

whose research grant made this study possible to the members of the

Supervisory Comittee for their aid and cooperation during the course

of this study, and to the author's fellow students and co-workers for

their helpful suggestions and assistance.

Finally, the author would like especially to express his apprecia-

tion to his wife for her moral support, constant encouragement and

understanding throughout the course of thisstudy.










INTRODUCTION


The critical shortage of natural rubber during World War II

was relieved by the development of synthetic materials. However,

these materials did not meet all the demands set up by the military.

For example, a rubber which was fuel resistant would lose its elas-

ticity when subjected to cold temperatures. One which would retain

Its elastic properties at low temperatures would fall in other respects.

The need for an elastomer which possesses good low-temperature pro-

perties, resists swelling when in contact with hydrocarbon fuels, and

resists deterioration by oxidizing agents was foreseen several years

ago. The arrival of the "Space Age"t has greatly magnified this need.

The Office of the Quartormaster General established and Is currently

sponsoring a long-range Arctic Rubber Program for the purpose of

discovering and developing rubber-like products which have the

desired properties.

One of the approaches which seemed promising was the modification

of existing materials by the introduction of fluorine atoms. Fluoro-

carbons are known to possess thermal and chemical stability and are

generally Imriscible with hydrocarbons. The comparable sizes of

fluorine and hydrogen also favored this approach since It was also

known that the introduction of bulky groups or atoms on butadiene

decreased the elastic properties of the resulting polymers.
Investigations Into the synthesis of fluorine-containing dienes

led to the discovery that haloalkanes containing fluorine would add to

olefins in the presence of peroxides. The resulting addition compounds










could then be converted to the desired olefin by chmnlcal methods. For

example, the work of Lllyqulst (11,17), Lovelace (IC), and G1ilman (5,16)

has demonstrated that such compounds as I,2-dibroMo-2-chloro- ,1,2-

trifluoroethane, CF2DrCFCIDr, and dlbronedifluoromethane, CFaBr2, In the

presence of catalytic amounts of free radical Initlators, would react

with such oleflns as ethene, fluoroethene and 2-fluoropropene to give

one-to-one addition products.

peroxides
CFaDrCFCIBr CH2-aCHZ CF2arCFCICH2CigBr I

peroxides
CFr CHCFFrCH -- CF2BrCH2CFDrCH3 II

The product front reaction I can be dehydrohalogenated and dehalogenated

to give 1,1,2-trlfluorobutadiene.

alcoholic
CF2BrCFCICHZCH2Pr CFPrCFCICH-CHa
base

zinc
CF2gDrCFC ICH-CH1 CFa-CFCI -CH
alcohol

Likewise, the product from reaction II can be dehydrohaiogenated with

tri-n-butylam-ine to give i,l,3-trifluorebutadiene.

R311
CF2BrCH2CFDrCH3 CF2a=CCF-=CH

The results of the polymerization studies of these and other

fluoroolefins showed that the basic assumptions were correct In that

the desired change in properties of the elastomers was effected.

However, it also became evident that the number of fluorine ators

Introduced on the rmnomer played an Important role In determining the

properties of the elastomer. With just a few fluorine atone, the change









was not appreciable while too many fluorine atoms caused the elastomer

to become stiff and brittle,

The Introduction of an atom or group of atoms on the monomer

which would provide the necessary flexibility seemed to offer an

approach to the solution of this problem. In considering the groups

which could be introduced on the monomer unit for the desired flex-

ibility, special interest was focused on silicon. The recent advances

made In the field of organo-slllcon elastomers were noted and consider-

atlon was given to the possible ways In which these units could be

Incorporated Into one molecule. Furthermore, the tetravalency of

silicon offered sites for additional reactions such as crosslinking

and three-dimensional chain growth,

Silicone rubber is known for Its exceptional thermal stability

and excellent electrical properties. The rubber Is not affected by

ozone, and the elastomer Itself has very low water absorption.

However, some of the chief disadvantages are swelling caused by solvents

and degradation by strong acids and bases. It has been found that

the swelling could be reduced if strongly electronegative atoms or

groups such as fluorine and nitrlle were substituted on the polymer

chain.

There are many methods used In the preparation of organo-silican

compounds. These methods may be combined Into three major categories:

direct methods, in which a silicon-carbon bond is formed; substitution

methods, in which a functional group is Introduced into an unsubstituted

organo-sillcon compound; and replacement methods, in which functional

groups already present are replaced with other functional groups. These









basic types of reaction are Illustrated below by means of equations.

Direct Methods

Cu
CH2-=CICHaCI + 31 (CHCg-CHH)aSiCIa
heat

SiCI4 CHsNMgar -- C6HSICI3

CICH2CH-CH2 + HSIC3 ---, CICH2CH2CH2SICI3

Substitution method


(CCi3)25IC12 + CaI light (CIIC)(CII3)SCl2

Replacement Methods

(CI13)3SICHatlgCI + CICOOCIs -- (CH3)351CH2COOCzHs


(CH3)3SICH-CH, HSCHaCOH ---- (CH,)3SICHa1IchSCH2COO


Of these methods, the most promising for laboratory scale

are the Grignard reactions and the addition reactions to alkenyl

silicon compounds. The use of these two methods for the preparation

of fluorine-containing alkenyl silicon compounds may be Illustrated

by tne following equations:

Grignard

CF2DrCFCICCHaCHMgBr + (CI3)35ICI --- CFaBrCFtCICH2CI2SI (CH3)3

zinc
CF2BrCFCICH2CH1(CH2S 3)3 alIcohol CFaCFCHaCHaSI (CH3)3


Addition

(C3)3iCH=CH2 + CFaBr r peroxide (CH) HCFCCFCr
(Cil,)3SicH]cH2 + CF2BrCFCIEr E- (CH3)3SI1iCrCH2CFtICF2Cr









These reactions are general and a great many products could be

expected by the use of the proper reagents. It should be noted

that the product from the addition reaction can be converted to a

conjugated diene which Is highly desirable from a polymerization

point of view.

alcoholic
(CH3)3SICHBrCHaCFCICF2Br (CH3)3SICH=CHCFCICFa2r
base

zinc
(CH3)3SICH=CH2CFCICF2r ---- (CH3)3SICHCCHCF=CF2
alcohol


Furthermore, by varying the other groups attached to the silicon,

and substituting more reactive chlorine for one or more of the

methyl groups, the possibility exist of converting this material

to siloxane linkages.

With these facts as a basis, It was concluded that the

presence of silane and slioxane linkages in the monomer might

supply the necessary flexibility In the elastomer backbone. It

therefore appeared that a study of the addition of fluorine-contain-

ing haloalkanes to vinyl and allyl silanes would be in order.

Consequently, the object of this research was to study methods of

preparing unsaturated organo-silicon compounds containing fluorine

for evaluation as possible low-temperature elastomers.









DISCU3SI XI


Free radical addition reactions to unsaturated systems have

become useful and important tools for the synthetic organic chemist.

A wide variety of compounds has been successfully added to olefins to

give simple one-to-one addition products. Among such compounds are

mercoptans (4), bromoesters (6), ketones (8), aldehydes (10) and

hloalllanes (7). An important consequence of these free radical re-

actions was the discovery that fluorine-containing haloalkanes would

add to oleflns and fluoroolefins to form useful Intermediates, These

products could easily and conveniently be converted to dines by

chemical methods (16,17,18).

The generally accepted mechanism for these reactions is the

one postulated by Kharasch (9) which involves a free radical, chain type

mechanism as Illustrated below:


0 0
II II
RC-0-0-CR R- RCOO + CO I


r: CX4 ----- X + CX3. 1


CX3. + CH2 aHR' CX3CQ1iR' III


CX) CXGCiiCi.' -CX3ClCIHXR' + CX3, Iv


The peroxide decomposes into free radicals which abstract an X atom

from CX4. X can be Iodine, bromine, chlorine or hydrogen. The

resulting free radical, CX3*, will then combine with an olefin




-7- -


molecule to foray the intermediate radical as shown in step 111. This

Intermedlate can now react In one of two ways: it can complete the

addition as seen in step IV, or it ca react with anithrr molecule

of olefin to form the two-to- one addition product.


CY3L'ia Clt + RtCH=CHg > CX3CHgr'HCCHIaCHP* V

Step V accounts for the higher boiling material found in these reactions.

Alkenyl silicon compounds are also known to undergo addition

reactions. Burkhard (2) has shown that various thiols will add to

vinyl and allyl silicon compounds to form the simple one-to-one

addition product. Soner (12) also found that butyraldehyde will add

to vinyltrimethylsilane in the presence of peroxides. Tarrant and

his co-workers (15) discovered that a convenient method of introducing

fluorine tr organo-silicon compounds involved the peroxide catalyzed

addition of perhaloalkanes to vinyltrimethyl- and vinyltrlchleros lanes.

Reagents such as CF3i, CFgCICFCII, CFvBrCFCIBr and CCI3sr gave good

yields of the one-to-one addition products. Furthermore, for example,

the product obtained from the reaction of 1,2-dibroMo-2-chloro-1il,2-

trifluoroathane with vinyltrimethylsilane was converted to the correspond-

ing diene.


CFaBrCFCIBr + CHR=CHSi(CH3)3 ---- CF2BrCFCICHCHBrSI (C3)3 I

base
CFaBrCFCICHaClDrSi (CH3)3 CFgDrCFCICII=CllSi (CH3)3 1

zinc
CF3BrCFCICHi=CH;SI(CH3)3 CfP=CFCIH=CHSi (CH3)3 III
alcohol










It is of interest to note that in step Il!i, product boiling

ruch higher than the starting material was also encountered. Further-

rmre, an standing, thi diene would convert to this higher boiling

material which has identified as being the cyclic diaer



CF2-CFC!l=Cli5 i (Cl3 )
I I
CFa-CFCi; =lS31 (CH3)3



The availability of starting materials determined the starting

point of tie present research. It was found that several vinyl and

allyl sllanes were coanerclally available. Among these was

vinyldimethylethoxysl lane, which could be easily converted to

divlnyltetrafmthyldislioxane by acid hydrolysis In benzene.


CH3- CH3 CHJ
I Hi I I
CII2=CI-S I -C 5 CH ai-0S I- 0-1 -CG H =CH2
I 11a0 1 I
ai3 CH3 CI13


This material offered an excellent starting point since one would

expect two products to arise from the addition reaction. One

product would result from the addition to one vinyl group and the

other product would result from the addition to both.

Consideration was also given to the addendwn. This material

had to meet several requirements. The first was that it be mally

obtainable In large qentitles. Furthermore, it was desirable that

this material be a liquid at room temperature with a boiling point

around 100 C. This material had to be sufficiently reactive to









propagate the chain reaction and give only one reactive species.

A material which adequately mct these requirements was 1,2,-

dibror.-2-chloro-1,l,2-trifluaroethane, Lilyquist (11) showed that

this nawterial gave rise to only one reactive species which was

CFa3rCFC.* It should further be noted that the products from this

eaterlal could easily be converted to a diane structure having a

CFC=C'F- grouping.

The addition of CFaCrCFCIBr to divlnyltetramethyldisiloxane

gave rise to two products as predicted. These products were

identified as being

C 13 C*3
I I
CFaBrCFC I C.-CHD3r-31 -0-S I -CHCH (I)
I I
CH3 C13


1-(1,4-dibror-3-chlero-3,4,4-trifilurabutyl)-3-vinyl-- I,,3,3-

tctrarioethyldlkl Ioexe, and


CU-3 CH3
I I
CFgBrCFC ICHCH cIr-S 3 -*- -Gi -Cl irCH CF; I CF2Cr (11)
I I
CH3 CUIS


1,3-bis-(I,4-dibroma-3-chlore-3,4 4-trifluarobutyl)-1,I, 3,3-

tetramethyldisl loxane.

It should be noted that the system used by Chemical Abstracts Is

employed throughout In naming these products. The numbers preceding

the substituents Indicate the silicon atom to which they are attached.


SI-0-Si
1 2 3










Furthermore, where there Is no ambiguity as to the position of the

substituents, the numbers will be omitted for ease of writing. For complex

structures and names, a number will be assigned and further reference to

this material will be made through number only.

Structures I and II were confirmed by elemental analyses, molecular

weight determination and Infra-red spectra. In each case, the analyses

were in good agreement with the expected values. The spectra for the two

were essentially the same except a band at 6.25 appeared for I which was

absent in II. This was expected since this band was attributed to the

silicon-vinyl group as observed In the spectrum of the Initial starting

material.

Several attempts were mwde to dehydrohalogenate I and II. Quinollne

and alcoholic potassium hydroxide were used as the dehydrohalogenating

agent. In the reactions of I and II with alcoholic base, a large quantity

of salt precipitated which was identified as being a mixture of potassium

chloride and potassium bromide. in each case, the organic material distilled

over a very wide temperature range. One of the fractions was believed to

be a product In which hydrogen chloride, rather than hydrogen bromide,

split out. Later efforts to prepare more of this material for nere con-

clusive data proved fruitless. The very wide temperature range of the

distillates led to the conclusion that the reaction was not a simple one,

and that alterations other than those expected occurred. A possible ex-

planation for this occurrence is the Instability of the silicon-oxygen bond.

It is known that strong bases easily cleave a silicon-oxygen bond. It was

further shawn In this research that weak bases also effected this cleavage

since such bases as quinollne and pyrldine caused the reaction mixture to









distill over a wide temperature range. The disiloxane linkage reformed

in all possible combinations when the reaction mixture was neutralized.

The possibility of dehalogenating the CF2BrCFCI- portion with

powdered zinc and alcohol was then studied. A substantial reduction

in boiling point and molecular weight would be expected from this react-

Ion. Furthermore, the double bond woud be expected to activate the

dehydrohalogenatlon reaction so that the reaction could be carried

out under less drastic conditions.

It was found that I reacted smoothly and easily with zinc In ethanol.

Furthermore, two fractions were obtained from the reaction mixture. The

infra-red spectra of these fractions were similar with Just a few minor

exceptions. Both showed strong absorption at 5.5M which Lllyquist

(II) assigned to an isolated CF2-CF- group. The lower boiling fraction

gave a negative test for chlorine or bromine whereas the higher

boiling fraction gave a quantitative test for bromine corresponding

to the value expected for the dehalogenated product. The lower boiling

fraction was believed to be

CH3 CH3
I I
CF2aCFCH2CHi-Si-O-S I-CH=CH2 (III)
I I
CH3 CH3

I-(3,4,4-trlfluoro-3-butenyl)-3-vinyl-l,l,3,3-tetramethyldislloxane.

Elemental analyses for this material were In good agreement with the

expected values. The other fraction was the expected

CH3 CH3
I I
CF2=CFCHaCHBr-SI-o-SI-CH-CH2 (IV)
I I
CH3 CH3









I-(I-bromlo-3,4,4-trl fluaro-3-butenyl )-3-vinyl-1,1,3,3-tetramqthyldlsi Ioxane.

In the reaction of II with zinc and ethanol, three fractions were

Isolated and identified as being


I I
CFa-CFC112CH 1-Si -0-3 I -CHiCli CF CFa V)
I I
CH3 CH3

I,3-bl s-(3,4;,--trlf I uoro-3-buteny I )-,1,3,3-tetra*ethy I d sl xane, In

which dehalogenatlon and reduction occurred at both ends of the molecule,

CH3 013
I I
CF2aCFCH2CItfr-S I -0-31 -laCI2CHFCF, (VI)
I I
013 CH3

I-(I-broao-3,L,-tr i fluoro-3-buteny )-3-(3,4,/t-tri fluaro-3-butenyl)-

1,1,3,3-tetramethyldislloxane, in which Cchalogenation occurred at both

ends but reduction occurred at only one end, and

CH3 C13
I I
CF,=CFClICHO r-SI --SI -CHDrCHaCF-CF2 (V I)
I I
C13 CH3

1,3-bls-(l-brroma-3,4,4-trifluoro-3-butenyl)-I,l,3,3-tetetrmethyldisiloxane,

In which only the expected dehalogenation occurred at both ends.

In order to further classify what appeared to be the replacement of

a brorine atom by hydrogen, the known compound CFaBrCFCICHaCHBrSI(CH3)3,

VIII, .wa treated In a similar manner. The results of this reaction were

consistent with those observed for I and II, In that two products were

Isolated and Identified as being

CFa-CFIClCHBr-SI -(CHS) (IX)

(I-broom-3,4,4t-trifluora-3-butanyl) trimethylsl lane, and










CFa=CFCHaCh2-SI-CHH3)3 (X)

(3,4,4-trifluoro-3-butenyi) trimethylsllane. This evidence conclusively

proves that reduction of the bromine does occur and probably proceeds

through the formation of a complex with the excess zinc which subsi-

quently reacts with the solvent, pulling off a hydrogen atom.

Reduction of the oC halogen was somewhat surprising in view of

the ready formation of CIjCFCHaCH2Br from CFaBrCFCICHaCHaBr without

evidence of reduction. However, It will be noted that this is a

general reaction for the oC-,bromo silanes prepared In this investigation

since each one formed the reduced product, CF2=CFCH2CHaSiX3, to some

extent.

Several attempts were made to convert IV to the corresponding

triene, in every case, the products distilled over a wide temperature

range which again was explained by the cleavage of the silicon-oxygen

bond.

Another monomer which was readily available was vinylpentamethyl-

disiloxane. The addition of CF2BrCFCIBr to this material gave a 60%

yield of the one-to-one addition product

CH3 CH3
I I
CFaBrCFCICHaCHBr-Si-0-Si-CH3 (XI)
I I
CH3 CH3

1-(I,4-dlbromo-3-chloro-3,4,4-trifluorobutyl)-1,1,3,3,3-pentamethyi-

dislloxane with only a very slight amount of higher boiling materials.

Several reactions were carried out with this material. Efforts to de-

hydrohalogenate failed. Reaction with zinc and ethanol resulted In the

Isolation of two products










CH3 CH3
C- CFCHCHa-S -O-SI -CH3 (XI )
I I
CH3 CH3

I-(3,4,4-trifluoro-3-hutenyl)-I, 3,3,3p3-pentamethyldls loxane, and

CH3 CH3
I I
CFa-CFCHaCHBr-SI-0-SI-CH3 (XIII)
I I
CH3 CH3

I-(I-bromo-3,4,4-trifluoro-3-butenyl)-I, ,3,3,3-pentamethyldl I oxane.

The reaction of XIII with quinoline was also carried out. The products

from this reaction distilled over a wide temperature range and could not

be positively Identified. However, a small amount of material came over
o
at 100 which was believed to be hexamethyldlslloxane. XIII readily

reacted with zinc and hydrochloric acid to give XII.

Another obtainable monomer was vinyldimethylchlorosilane. The

addition of CFgBrCFCIBr to this material gave a 30% yield of the desired

one-to-one addition product.

CHM
I
CF&BrCFC IHCHCHD r-SI-CI (XIV)
I
CH3

(1,4-dlbromo-3-chloro-3, ,4-trlfluorobutyl)-dimethylchlorosl lane, and a

large quantity of higher boiling material. It was later discovered that

this addition product was contaminated with benzoic acid (a by-product from

the initiator) which caused the analysis to be In error. The benzolc

acid and XIV formed a constant boiling azeetrope. oJarmal chemical methods

for removing the benzoic acid could not be employed since the chloro-

sllane will react with water to form the disiloxane. Efforts to de-





-15-


hydrohalogenate XIV were unsuccessful; with quinoline and pyridine, a

precipitate Imrediately formed and the reaction products could not be

Identified. Alcoholic base gave a mixture of products which distilled

over a wide temperature range. Aqueous base gave the sy~metrical dl-

slloxane II as the principal product. It was from this reaction that

the benzocl acid contamination was discovered since the boiling points

of the dislloxane II and benzoic acid were sufficiently different to

afford separation by distillation.

The addition of CF2BrCFCIBr to vinyldimthylethoxysilane,

C 2-CHHS(CH3)aCC3H5, was also studied. Several Initiators were tried

and a c'-azo-dl-Isobutyronltrile gave the largest conversion of elefin

to addition products. A constant belling fraction was Isolated; however,

the analyses of this material did not correspond to the values expected

for the one-to-one addition product. Furthermore, the infra-red spectrum

showed a band at 6.24 A which Indicated that a material containing a

silicon-vinyl group was present. The reaction products were further

reacted with zinc and ethanol In order to obtain the products In a form

such that they could be separated and Identified. Two fractions were

Isolated from this reaction and were Identified as being III and V.

Therefore It appeared that the addition mixture consisted of

CH3 CH3
I I
CF2BrCFCI ICHHBr-Si-0-Sl -CH--CH (I)
I I
C13 CHa

and
Ci3

CFaBrCFCICllaCtCr-SI-OCJ3 (XV)

H3




-16-


(l,4-dibromo-3-chlore-3,4, -trlfluorobutyl) dimethylethoxysilane. The

formation of I, although unexpected, can be readily explained by

considering the ease of hydrolysis of the ethoxysllane to the dislloxene.

It is therefore not unreasonable to believe that oume of the vinyldimethyl-

ethoxysllane hydrolyzed to the corresponding disiloxane and that addition

then occurred to both reactants.

The precursor for V was postulated as being XV since the boiling

points of I and XV are expected to be or the same order of magnitude.

II cannot be the precursor because this material is known to boll at a

temperature considerably higher than was found for the mixture. The

explanation offered for the formation of V from XV was that the zinc

hallde, a Lewis acid, caused the conversion of the ethoxysilane to the

dislloxane.

Another monomer which was readily obtainable was divinyldlmethyl-

sllane. Since It was found that the presence of silicon-oxygen bonds

led to complicated mixtures In the reactions with base, divinyldimethyl-

silane offered the advantage of not having the slloxane linkage but

still presenting two reactive sites. The addition reaction resulted In

good conversion of monomer to products. Two fractions were isolated

fr3m this reaction mixture. The higher boiling fraction, when reacted

with base, gave a material with the same properties as the power boiling

fraction. This factor seems to indicate that some thermal dehydro-

halogenation occurred during distillation. The infra-red spectra of

all these materials indicated that these fractions were contaminated

with benzoic acid. Furthermore, the addition products were found to

readily react with zinc and ethanol and a portion of the resulting










reaction products was identified as being

CH3

CF2=CFCH2CH2-SI -QH =CH2 (XVI)
I
CH3

vinyl-3,4,4-trifluoro-3-butenyldlmethylsi lane. It therefore was con-

cluded that the reaction mixture consisted of the desired addition

product

CH3
I
CFEBrCFC I Cai2Cl r-S -CH=CH, (XVII)
I
CH3

vinyl-(1,4-dibroma-3-chloro-3,4,4-trifluorobutyl)-dimetthylsilane, and

the dehydrohalagenated product

CH3
I.
CFBIrCFCICHaCH-SI-CH=CH2 (XVIII)
I
Cal

vinyl-(4-broam-3-chloro-3,4,4-trlfl uro-l-butenyl)-dimethylsitane.

The reason for the inability to isolate the conjugated system when the

mixture was reacted with zinc was that the conjugated dlene either

polymerlzed or dimerized since some higher billing material remained In

the distillation flask.

An Interesting phenomnon was observed in the addition of CF2rCFCIBr

to allyltrimethylsllane. It was found that cleavage of the carbon-

silicon bond occurred and that the olefin CF~CrCFCICHCH-CH.H., XIV, was

formed. The position of the double bond was confirmed by the debiao-

genation of this material to the corresponding dleve. The Infra-red

spectrum of the diene was identical with that obtained by G inen (5)









for CFa=CFCHCa=CHCH.

Sommer (/1) has shown that allyltrlFnethylsllane reacted with

electrophilic reagents such as bromine, hydrogen chloride and sulfuric

acid to give propylene and the corresponding silicon residue. Further-

orre, the addition of hydrogen bromide to allyltrlmethylmllane did occur

at low temperatures; however, propylene evolved as the material was

heated and bromotrimethylsilane remained as the residue. The following

eirchanisn was postulated by Soamer to account for these facts:
+
X Y- + CHa=CHC'a-SI (CH )3 XCH.CHCH2SI (CH3) + Y-

1-. I?3,
XCH-CH2:SI . . Y ----- CH2CH-CH2a YS1(CI3)3
iCH3s a

In considering a mchanlsm for the cleavage observed In this study,

It must be remeRbered that free radical conditions existed and that the

Intermediate radical which forced from the initial attack could rearrange

to account for the cleaved products.


CF&BrCFCI + CHa-HCCHaSl(CH3)3 CFABrCFCICHCIHCH2:51 (Ct3)3 I

CFXBrCFCICH2CHCHg:SI(CH"3)3 CFa2rCFtCICHZCl CIIC, SI (CH,3)3 II

or

CF2BrCFCItr
CI ------ CF2BrCFCICHaCHBrCHZSI (CII1)3 + III

CF1arCFC I

As can be seen from the above series of equations, the Intermediate can

react in two ways: It could rearrange to form the olefin and mere stable

*SI(CH3)3, step II; or It could complete the addition by abstracting a

bromine from the addendum, step III. It is entirely possible that both





-19-


reactions occurred to some extent since a small amount of higher boiling

material was formed. However, the rearrangement step predominated.

The reaction of CF2BrCFCIBr with diallyldinrthyls lane was also

studied. It was found that this reaction gave a good conversion of

olefin to products and that cleavage was not encountered. However, It

was observed that hydrogen bromide split out during distillation, A

fraction was Identified as being the result of the addition to one allyl

group In which hydrogen bromide spilt out
CH3
CF2BrCFC I Cl2CHiCH-Sl -CHaCH=CH2 (XX)
CH3

al yl-(5-bromo-4-chl ore-4,5,5-trifluore-l-pentenyl)-dimethyisi lane.

This fraction amounted to only ten percent of the higher boiling material.

The remaining residue could not be separated into its various components.

Butler (I) has reported that 1-6 diene systems will undergo cyclic

intra-intermolecular polymerization. Freidlander (3) showed that

cycllzation also occurred when diallyl ether was reacted with broo-

trichloromethane. Furthermore, the hetero-atom could be sulfur or

nitrogen. However, the product obtained in this laboratory is believed

to be linear since its Infra-red spectrum showed two peaks at 6.02 and

6.15 kA This indicates that there are two types of double bonds. If

cycllzation occurred, only one double bond would be expected. An attempt

was made to quantitatively determine the double bond content of this

material. However, the results were Inconclusive since widely divergent

values were observed.

The position of the double bond was determined by dehalogenating










XX to the correspo. ding triene. The resulting product could have

either of the following structures


CH3
I
CFa2CFCHzCliCI-SI-CI2lQ=CHa (XXI)
1

CHz
or
CHl

CF2 =CFcI IU'01 12-31 C-Q1 a2 1I02 (ulxI I)

CH3

The infra-red spectrum of the reaction product was compared with those

obtained by Gillrin (5) for CFa-CFCH- CQC1 (A) and CFa-CFCIllCI=CH1 (B).

The spectrum of the material In question was more nearly Identical

with (D) than with (A). Therefore it appears that the structure XXI Is

preferred. Furthermore, Lilyqulst (II) pointed out that Isolated CFa-CF-

groups absorbed sharply at 5.5 A, whereas when this group was conjugated

with -CH-CH-, a shift to 5.65 was observed. These data alsi sub-

stantiate structure XXI.

Several other reactions were also studied. Somer (13) has report-

ed that concentrated sulfuric acid will selectively cleave a methyl

group from substituted sllanes and that the resulting sulfate ester would

hydrolyze to the dislloxane. The possibility of converting CFaBrCFCICHa-

CHBrS3(CH3) to the disiloxane II was studied. It was found that this

conversion was successful but in extremely low yields. Furthermore, it

was felt that the reaction did not end with the cleavage of one methyl

group since higher boiling materials were encountered. The formation

of this material probably resulted from the reaction of two or possibly





-21-



all three methyl groups with sulfuric acid.

The effect of excess base on sllanes was also studied. Prolonged

treatment of CFBrCFCICCH=CHSI(CH3)3 with base produced cleavage to

CF2CrCFCICH=iCH and (CH3)SIOSl(CH3)3a The boiling points of these

two materials are Identical so that the mixture was Identified from

its Infra-red spectrum.














C.1 1t 0 0 I1
. 0 to ." %


'v 'a
*i 5


I -








1 N


SLN


um 0 0 o0 0 m Cf
CN N N N N N CC


t1 CO L' L uCi
0n~ uL~


Si


IEl

- (r -A
.3 t) Ul'


S 0 0 N3
l. 0 -N -


1% 0 0




o0








N


Ln
L -


3l m
-





m .

2"U

L. 00
3 n.
Li Li
I 0r
(11 ID I
5 5 5


-


4- -
*n


0
Li





Li






Id


U'
.3

C,'
U' .3
to -


M
x



5 I
n

- eq
I> Ir-
0 -

- n
" 5




5



La Li
oT i

i5 E
La. Li

o,
L L.
(. 1-1


a ?
V% r


j.














0
SO--0 0 \ (





'r 0 U 0 0 9 O
to c3 ac S m 9
Sa -




cc
-: - -S -B -^r^ - -- o
4j 0 m 0 N m m p m









0 0 .C




o









u '-










U MN U
(1 a S ?a 4
-5 i-
o - Q n -

Lo i- w w wiL -











o 0.
St I >



L3 x















TABLE 2

ANALYSES OF THE CODHPOUDS PREPARED


MRd Ialogen % Carbon % Hydrogen
Cpd, Caled, Fd. Cglcd, Fd. Calcd. Fd. CIIcd. Fd.


1 C7.26

II 117.28

XIV 65.78

XI 83.06

XX 69.73

IV 73.90

III 66.30

V 75.94

VI 83.60

VII 91.28

XII 62.42

XIII 70.10

IX 51.45

X 43.77

XVI 47.92

XXI 53.74

.IX 37.42


8.T70

17.80

67.30

82.90

69.40

74.20

66.70

77.70

84.80

93.50

61.65

70.38

51.50

43.60

4. 15

52.65
17? A


15k.6 151a5

123.2 123.6a

8.95c 7.85c

150.2' 150.34

167.7a 167.7a

23.0b 22. b

0 0

0 0

1i.6 18.6

31.,b 30.9b

0 0

23.80b 23.80b

30.S5b 31.02b

0 0

0 0

0 0
118.8a 1189a


25.89 26.21 3.91 4.01

19.52 19.70 2.46 2.64


34.60

44.72

41.13

33.60

28.40

42.60




46.70

49.46

54.60


35.01

41.69

41.39

33.16

29.06

42.40D




46.60

49.78

54.13


5.22

7. 1.'

5.75

4.46

3.57

7.47




7.11

6.74

6.82


5.43

7.21

5.94

4.41

3.65

7.52




7.25

6.97

6.95


% Bri c hydrol. % Cl(contmilnated with benzoic acid)


a Ag eq.; b


1











EXPERI IENTAL


in general, all reactions were carried out in a three necked,

round bottomed flask equipped with stirrer, reflux condenser and,

when needed, a dropping funnel.

The best procedure for the addition reactions was found to be

the one in which all the reactants were heated and stirred together
o
for six to ten hours at 90 to 100 C. Although this method is con-

ducive to the formation of two-to-one and higher ratio products, it

by far gave the best conversion of olefin to desired product. The

method, in which the initiator is dissolved In the olefin and solvent,

and added to the hot addendum over a period of time, resulted in the

recovery of 50 to 70% of unreacted olefin. After the reaction was

complete, the mixture was crudely distilled to remove the excess

addendum. The residue washed with a solution of sodium bicarbonate

to remove any benzoic acid, dried and then subjected to vacuum

distillation.


-25-










GUIERAL COfSIDERATIONS


All temperatures reported In this dissertation are on the

centigrade scale and are uncorrected. Where possible, distillations

were carried out using a 60 cm. electrically heated, Jacketed column

packed with I/8 Inch glass helices. For small amunts of material,

a 22 cr. column of the above description was used. For extremely high

boiling and viscous materials, a 30 cm. Vigereaux column was used.

Pressures under 10 im. were determined bL a McLead gauge.

Refractive indices were determined with an Abbe refractometer at

the temperature Indicated. Densities were determined using a one

milliliter pycnometer calibrated with distilled water at 200 C. and

corrected to 40 C. Molar refractlens were calculated using the

Lorenz-Lorentz equation. The values for the bond refractions were

taken from Warrlck's (19) application of Denbigh's bond refractions

to organo-slIlcon chemistry.

Analyses for carbon-hydrogen content were carried out by Galbralth

Laboratories, P. 0. Box 41'7, Knoxville, Tennessee. Halogen analyses

were carried out by the author, using the Parr sodium peroxide fusion

method for the decomposltlon of the sample and the Volhard method for

determining the halogen content. Where possible, the analysis was

reported as percentage halogen. In cases where both chlorine and

bromine were present In the same molecule, the analysis was reported

as silver equivalent. Molecular weights were determined using the

freezing point depression method with benzene the solvent.

The infra-red spectra were obtained on a Perkln-Elner Ibdel 21










double beam, recording, infra-red spectrophotometer. All absorptions

are reported In microns.

The following abbreviations were used to describe the relative

intensities of the bands:

w - - - - very weak

w - - - - weak

m -------- medium

ms -- - - - medium strong

s - - - - strong

vs -- - - - very strong

brd - - - - broad

smear - -- - - a band which covered a wide range

shid - - - -- shoulder

Where possible, the reactants were purchased. Most of the vinyl-

and allyl sllanes were obtained from Peninsular Chem Research, Inc.,

Galnesville, Florida. Reactants not commercially available were pre-

pared In the laboratory by procedures described in a later section of

this dissertation.


A. Additions of I,2-Dlbrono-2-chloro-lI,2-trlfluoroethane to

Alkenyl Silicon Compounds

I. Divlnyltetranethyldlslloxane

A typical run Is described as follows: A solution of dlvlnyltetra-

methyldlslloxane (186 g., I mole), CF2BrCFCIDr (2200 g., 8 moles) and

benzoyl peroxide ( 10 g.) was refluxed and stirred for ten hours. The

excess CFaDrCFCIDr (henceforth called dibromlde) was distilled off and

the residue washed with a solution of sodium bicarbonate. The organic




-2C-


material was dried over CaCil and distilled under vacuum. Two

fractions were obtained. The lower boiling fraction, b.p. 80-

100 /0.5 wm., 257 g., (50 yield), was identified as the One-to-

one addition to one vinyl group,l. A center cut had the following
0
properties: b.p. 85 0S/b.5e; n20 1.452h d0o 1.407. Anal. Calcd.

far CioHeBr2CIF3SIa0: fRd 87.26j Ag eq. 154.6; %C 25.89; H

3.91 tW 464,. Found: Rd C-3.70; Ag eq. 154.5; ;C 26.21; 214 .01;

W 422.

Infra-red absorption: (In microns)

3.26(w); 3.37(m); 6.24(w); 7.09(m)j 7.96(S); C.40(ms); 8.76(s);

9.50(brd a); 10.15(ms); 10.45(m); 11.30(m); 12.00(brd s); 12.65(brd s);

/1.20(brd as).

The other fraction, b.p. 160-160/3.5 ms, 114 q. (15% yield), was

identified as the one-to-one addition to both vinyl groups,ll. A

center cut had the following properties: b.p. 163-165/1 rm; n45

1.4820; d2s 1.795. Anal. Calcd. for L-fCt iBr4ClaF6SI20: NRd 117.28;

Ag eq. 123.2; %C 19.52; H 2.4.6. Found FRd 117.80; Ag eq. 123.61

%C 19.70; %I 2.64.

Infra-Red absorptions:

3.40(m); 7.06(m); 7.36(w); 7.96(s); 8.4O(s); e.80(s); 9.50(brd s);

10.15(s); 11.30(s); 11.95(brd s); 12.65(brd s); 13.55(w).

The only difference between the two spectra is the disappearance

of the silicon-vinyl C-C stretch absorption at 6.24 '- This Is
expected for the latter compound.

2. Vinylptntamethyldisl loxane

A solution of 100 g. of dibromide, vlnylpentamethyldlisloxene









(80 g., 0.46 mole) and 10 g. of benzoyl peroxide was added to 450 g.
0
of dibromide which had been previously heated to 92 The solution was

added In 25 al. portions and then reflued for an additional 4 hours.

The excess dlbromide was distilled through a Clalsen head until the
0
pot temperature reached 175 The residue was. washed with a solution

of sodium bicarbonate, dried and distilled. A fraction, b.p. 84-89/

1.6-2.0 mm., 124 g., 60 % yield, was collected and Identified to be

the one-to-one addition product XI. A center cut had the following
o
properties: b.p. 81-82 /12 m.; n2O 1.4470; d20 1.455. Anal.

Calcd, for CHtaSBraCIF3SiO: M d 83.06; Ag eq. 150.2. Found:

11Rd 82.90j Ag eq. 150.3.

3. Vinyldirncthylcthoxvsilane

A solution of vinyldimethylethoxysllane (100 g., 0.77 mole),

dibromide (540 g., 2 moles) and aGt-azn-lJ-Ilrbutyronitrile (5 g.)
o
was heated to 80 for 10 hours. The reaction mixture was worked up
0
In the usual meager. A fraction, 76 g., b.p. 72-90 / I r. was
o
collected. A center cut had the following properties: b.p, 81-82 /

0.9 m.; n22 1.4560; da2 1.5110. Anal. Calcd. for CSHt143rCIF3SI0:

Ag eq. 135, Found: Ag eq. 145.5. Infra-red absorptions:

3.40(ms); 5.69(n); 6.12(w); 6.24(w)l 6.84(w); 6.95(w); 7.10(m);

7.35(w); 7.62(w); 7.75(m); 7.92(s); 8.20(m); 8.45(ms); 9.50(brd s);

10.25(w); l1.25(brd s)j 11.95(brd s); 12.50(brd s).

It appears thatthe product Is contaminated with other materials.
The bands at 5.68, 6.12 and 6.24 are not expected and the absorption

at 6.21. is characteristic of sillcon-vinyl. It appears that some of

the ethoxysilane hydrolyzed to divinyltetramethyldisilaoxane and that









addition occurred to both components.

4. Vlnyldlmethylchlerosl lane

A solution of vinyldimethylchlorosllane (157 g., 1.3 mole),

benzoyl peroxide (10 g.) and dlbromlde (1450 g., 5.2 mole) was re-

fluxed far 10 hours. The reaction mixture was worked up In the usual

manner with care taken to exclude moisture. A 28 % yield of the

one-to-one addition product XIV, 144 g., was obtained. A center cut
0
had the following properties: b.p. 67 /0.8 ma.; n25 1.4721; da

1.663. Anal. Calcd. for C6HgBraClaFSI: MR 65.78; hydrol Cl 8.95%.

Found Rd 67.39; hydrol. Cl 7.85 %.

Infra-red absorption:

3.40(m); 5.60(w); 5.85(m); 7.10(n); 7.95(s); 8e.(s)) 8.78(s);

9.20(ms); 9.75(as); 10.10(s); 11.25(s); 1I.85(s); 12.40(brd s) 14.05(mw).

The bands at 5.60 and 5.85 Indicate that the material may be con-

taminated with benzoic acid.

5. ODvlnvldimathylsllane

A solution of divlnyldlmethylsilane (100 g., 0.9 mole), dlbromlde

(1000 g., 3.5 male) and benzoyl peroxide (10 g.) was refluxed for

4 hours. The reaction mixture was worked up In the usual manner and
0
110 g. of material boiling between 40-80 /I m. was collected. This

material was fractionated to give two cuts. The first had the following

properties: b.p. 51-55/2.2 mm.; n20 I. 426; d2a 1.337; yield 25 g.

This material was believed to be XVIII, the addition product to one
vinyl graup in which hydrogen bromide split out. Anal. Calcd. far

CaHi1DrCIF3SI: Ag eq. 153.7. Found: 161.8.





-31-


Infra-red absorptions:
3.40(m); 5.80(brd w); 6.20(shld w); 6.26(w); 6.85(w); 7.09(ms);

7.65(w); 7.98(s); 8.15(m); 8.32(s); 8.75(s); 9.60(brd s); 9.93(as);

10.10(s); 10.50(brd s); 12.00(brd s); I4.00(brd s).

The band at 5.80 Indicates that the material may still be

contaminated with benzolc acid. This fact could account for

the discrepancy In the analysis. Furthermore, the shoulder at 6.20

Indicates that hydrogen bromide did split out.

The second fraction, 30 g., had the following properties:

b.p. 74/1.6 mm.; n20 1.4762; d20 1.566. Anal. Calcd. for CeHiaOra

CIF3SI: Ag eq. 129.5. Found: Ag eq. 137.7.

Infra-red absorptions:

3.40(m); 5.60(w); 5.80(m); 6.26(w); 7.09(ms); 7.59(w); 7.97(s);

8.40(s); 8.75(s); 9.10(ms); 9.46(s); 9.93(ms); 9.46(s); 9.93(ms);

10.10(s); 10.42(rs); 11.30(s); 12.00(brd s); 12.85(brd s); 14.10(m).

This material is believed to be the one-to-one addition product

XVIllwhlch Is still contaminated with benzolc acid. The Infra-red

spectrum has bands at 5.60 and 5.80 to support this assumption. It

therefore appears that the one-to-one addition to one vinyl group

does occur and that some of this material Is dehydrohalogenated

during distillation.

6. Allyltrinethylsilane

A solution of allyltrimethylsilane (50 g., 0.48 mole), benzoyl

peroxide (5 g.) and dlbromide (100 g.) was added dropwise to 700 g.
0
of dibromide which had been heated to 90 The excess dlbramlde was

removed by distillation and as the pot temperature reached about
0
170 hydrogen bromide began to evolve. A fraction, 35 g., 30% yield,









0
was collected and had the following properties: b.p. 121.5 ; n23

1.41151 d3 1.588. Anal. Calcd. for CsHsBrCIF3: MRd 37.421 Ag

eq. 118.8. Found: MFd 37.10; Ag eo. 11C.9. This material Is

CFaBrCFCICH2CH-CH, '(XIX).

Infra-red abserptiens:

5.37(vW)i 6.04(w); 6.97(m)i 7.97(m); 8.30(s); 8.75(s); 9.55(s);
10.20(s); I0.75(s); 11.25(s)j 11.90(w); 12.10(w); 12.85(s); 13.60(m);

14.40(s).

Some higher boiling material was also farmed In the reaction.

However, this material could not be positively Identified. It Is

felt that this material was the one-to-one addition product which would

undergo cleavage during distilatlon.

7. Diallyldimethylsilane

A solution of diallyldlmethylsllane (60 g., 0.43 mole), dl-

bromide (276 g., I male) and eGK'-azo-dl-lsabutyronltrlle (3 g.) was
o o
heated to 70 for 3 hours and then to 95 for 2 hours. The excess

dlbromide was distilled off and the residue distilled under vacuum.

Hydrogen bromide evolved throughout the distillation and the distillates

appeared to be saturated with HBr. The distillates were combined,

washed with a solution of sodium bicarbonate and redlstlled. A

fraction was Identified as being the one-to-one addition product to

one allyl group In which hydrogen bromide spilt out XX. A center

cut had the following properties: b.p. 61 0f.5 ma., na 1I.5C0;

da' 1.350. Anal. Calcd. for CGoHIBrCIF3SI: 'Rd 69.73; Ag eq.

167.7. Found: MRd 6.401 Ag eq. 167.7.





-33-


Infra-red absorptions:

3.45(m); 6.04(ms); 6.17(ns); 6.95(m); 7.13(m); 7.97(s); 8.35(s);

8.85(s); 9.50(brd s); 10.20(s); 10.75(brd m); 12.00(brd s); 12.50(brd s).

This material accounted for only 10% of the higher boiling

residue. Attempts to separate and Identify the other components failed.

Another run of the above reaction was tried In which a solution

of allyisilane, dlbromide and initiator was added dropwise to the
o
remaining dibromide which had been heated to 70 About 65% of

unreacted allyisllane was recovered with only a small amount of

addition products.


B. Reactions of the Addition Products


1. CFjCrCFCICH2CHBr(CHa),i0S51l(CH-i)CH=CHI (1)

a. With Dase

A solution of potassium hydroxide (56 g., I mole) dissolved

In methanol (500 cc.) was added dropwise to a stirred solution of

I (257 g., 0.56 mole) and 200 cc. methanol. The stirring was con-

tinued for 3 hours at room tcrnperaturc, after which the precipitated

salt was filtered off. The methanolic solution was washed with cold

dilute HCI and the orgacle layer dried and distilled. The distillate was

collected over a wide temperature range (85/500 mr to 8a0/.7.a.).

All efforts to separate this mixture into its components falledand none

of the fractions could be identified.

b. tilth Zinc and Alcohol

Eighty-eight grams, 0.19 male, of I were added dropwise to

a slurry of zinc(20 g., xs) and methanol (300 cc.). The mixture was

heated for two hours after which time the excess zinc and zinc halide





-34-


we filtered off. The methanolic solution was drowned with cold water.

A gelatinous precipitate formed which dissolved when neutralized with

dilute HCI. The organic layer was separated and the aqueous layer

extracted with ether. The ether extracts were combined with the

organic layer, dried, and distilled. Two fractions were obtained,
0
the first having the following properties: b.p. 54-55 /2.5 Rmn.

na0 1.3992; d80 0.971. Anal. Calcd. for CIoH19FIzS10 M 66.631

% C 44.72; % H 7.1;1 NW 268. Found: MRd 66.70 $% C t4.69; % H
d
7.21; jW 297.

Infra-red abserptions:

3.37(s); 5.23(w)( 5.52(s); 5.74(m); 6.24(m); 6.93(m)i 7.08(s);

7.75(s); 7.95(s); C.C5(s); 8.42(s); 8.55(s); 9.50(brd vs); 9.C0(s);

I0.45(9ms); I.lO(ms); Il.90(brd s); 12.70(brd s); 11.20(s).

It appears that this fraction is the dehalogeriated product In

which the c~ bromine was replaced by hydrogen.Ill.

The second fraction had the following properties: b.p.
o
83 /2.5 ma.; na2 1.4296; d'a 1.198. This moterlal is the dehalogenated

product IV. Anal. Calcd. for CloHij1rF3SIg0: MRd 73.901 g3r 23.0;

%C 34.60; %H 5.22. Found: Mfd 7?.20; 0Br 22.8; %C 35.01; %H 5.43.
Infra-red absorptains:

3.37(s); 5.23(vw)j 5.52(s); 5.83gWI 6.24(m); 6.93({a); 7.08(ms);

7.45(w); 7.75(s); 7.95(s); 8.05(s); ~ft(s); 8.55(s); 9.50(brd s);

10.05(s); 10.45(m); 11.10(s); 11.90(brd s); 12.70(brd s); 14.20(s).

c. CFa-CFCH2CHTr(CH3)aSICSI(CH3)aCH-C1((IV) with Quinellne

The dehalogenated product (24 g.) was heated with 50 g. of










qulnoline and the distillate collected as it formed. The crude
distillate was redistliled several times in order to separate It

into its various components. All efforts to identify these fractions

were unsuccessful.

2. ICF2BrCFCICHaCHBr(CH3)2Si ]a (II)

a. With Alcoholic Case

A methanollc potassium hydroxide solution consisting of

2,0 g. of base In 500 cc. of methanol was added dropwise to 114 g.

(0.15 moles) of Ii. The reaction was kept six hours at room temperature.

The salt which precipitated was filtered off and analyzed to be a mix-

ture of KCI and KBr. The filtrate was drowned with cold dilute

hydrochloric acid and the organic layer separated, dried and distilled.

This material distilled over a wide temperature range and none of

the fractions could be identified positively.

b. 'Jitn Zinc and Alcohol

To a solution of ethanol (200 ml.), dioxane (200 al,), and

zinc (33 g., 0.5 moles) was added 185 g. (0.25 moles) of II. The

reaction was kept at room temperature for two hours. The mixture was

filtered, the filtrate washed with dilute HCI, and the organic layer

separated. The aqueous layer was extracted with ether. The ether

extracts were combined with the organic layer, dried and distilled.

Three fractions were obtained. The first, V, corresponded to de-

halogenatlon and reduction on both ends of the molecule. This

fraction, 10 g., 5% yield, had the following properties: b.p. 93-

960/ 5 ma, In2o 1.3975; dao 1.085. Anal, for C,2112oFSI20: Calcd.









MR 75.94; C Ai4.13; 1i 5.751 iW 350. Found: ;Rd 77.70; %C 41.39;
d d
1H 5.94; IW 360.
Infra-red absorption:

3.45(m); 5.56(s); 6.95(m); 7.1E(n); 7.75(s); 7.95(s); 8.06(s);

8.45(s)i 8.56(s)1 9.35(brd s); 10.05(as); 11.20(ms); 11.95(brd s);

12.65(brd s); I1.25(brd w).

The second fraction, 10 g., 5% yield, was Identified as the

product in which dehalogenatlon occurred on both ends with the re-

duction of only one bromine, VI. This material had the following
0
properties: b.p. 80 /18.8 nem. n23 1.4238; d23 1.282. Anal. Calcd.

for ClaHIgBrF6iSl0: MRd 83.60; -Br 18.6; %C 33.60; H 4.46; 6W 429.

Found: M C84.80; jIr 18.6; %C 33.16; jH 4. 41j H1 422.

Infra-red absorptions:

3.39(m); 5.54(s); 5.90(vw); 6.95(mu); 7.07(n); 7.75(s); 7.95(s);
e.09(s); 8.44(m); 9.35(brd s); 10.00(m)1 11.15(m); 11.95(brd s)j
12.60(brd s); 14.15(brd w).

The third fraction, 30 g., 20% yield, had the following properties:

b.p. 103-106/A0. mm.; n3 I.4405; d3 1.426. This material was

Identified as the product In which dehalogenatlon alone occurred at

both ends of the molecule, VII. Anal. Calcd. for CaH-iBraFiSI20:

1Rd 91.28; %Br 31.41 %C 28.40; %H 3.57. Found: iRd 93.50; %Br 30.9;
%C 29.36; H 3.65.

Infra-red absorptions

3.38(ms); 5.54(s)j 5.90(vw); 7.08(m); 7.70(s); 7.95(s); 8.10(s);

8.46(s); 9.50(s mear)j 11.20(m); 12.00(m); 12.50(smear); 14.25(mear).





-37-


3. CFpBrCFCICHaCHBr(CH3),SiOSi(CH3)3 (XI)

a. With Pyridine

A solution of pyrldine (30 g.) and XI (40 2., 0.9 male) was

heated and stirred for 3 hours. The pyridlne was washed out with water

and the organic layer dried and distilled. The only fraction identified

was unreacted XI.

b. With Zinc and Alcohol

XI (45 g., 0.1 mole) was added dropwise to a slurry of zinc
(10 g.) and ethanol (250 ml.). The mixture was heated for an
additional 4 hours and the reaction mixture worked up in the usual

manner. Two products were isolated. The lower boiling had the follow-

ing properties: b.p. 62-63/15 mm.; n0o 1.3869; d2a 0.975. This

material was XII, the dehalogenated reduced product. Anal. Calcd.

for Cgl19rSiaO: MRd 62.42; 5C 42.60; %H 7.47. Found: l d 61.65;

%c 42.40; 41 7.52.
Infra-red absorptions:

3.45(m); 5.54(s); 5.82(w); 6.95(w); 7.75(m); 7.97(s); 8.l6(ms);

C.45(n); 8.56(m)j 9.35(brd s); 10IO.0(); 11.85(s); 12.30(mear).
The second fraction, 20 g., 61% yield, had the following properties:

b.p. 92-93 /15 mm.; n2a 1.4186; da0 1.206. This material was XIII, the
dehalogenated product. Anal. Caicd. for CiigS8rFPSiX0: MRd 70.10;

3Dr 23.8. Found: Rd 70.33; Br 23.S.
Infra-red absorptions:

3.45(m); 5.54(s); 5.c2(w); 7.10(m); 7.65(s); 7.82(s); 7.95(s);









8.10(s); 8.L4(s); 9.35(brd s); 9.95(m); 11.85(brd s); 12.50(s);

12.90(m); 13.25(m).


C. Reactions of CFra-CFCHOrCH,)rS(CH)IS10(CHs)3 (XIII)


I. With Zinc and Hydrochloric Acid

XIII (15 g., 0.05 mol was heated with an excess of zinc

and -l. hydrochloric acid. The mixture was allowed to stand overnight

and the organic layer separated, dried and distilled. The distillate

had the following properties: b.p. 62-63 /15 M.1 n"o 1.3872; dao

0.980. Yield 4.5 g. These physical constants a re Identical with those

for XII.

Ii. With Qsinpllne

XIII (15 g., 0.05 mole) was heated with an excess of

qulnollne (13 g.) and the distillate collected as It formed. Re-

distillation of the crude material resulted In several fractions,

none of which could be Identified.


4. The Products obtained from the addition to Vlnyldlmethylethoxysi lane

This mixture (72 g.) was added dropwlse to a slurry of zinc and

ethanol. The reaction was exothermic. The mixture was heated for an

additional 2 hours and then worked up In the usual manner. Two products

were isolated from the reaction mixture. The lower boiling fraction,

15 g., had the following properties: h.p. 51-54 /amm., n2o 1.40t10

dao 0.9940. Anal. Foend: No Cl or Br-, %C 45.56; V 7.19; M 275.

These data along with the Infra-red spectrum Indicated that this material

was III. Calcd. for CloH111iFSi0: %C 44.721 H 7.14; M1 269.









The second fraction, 25 g., had the following properties: b.p.
93-96 /5f0n.i n2a 1.3975; d20 1.085. This material was identified as

being V. Anal. Calcd. for CtaHaoF6SigO: 01 5.75; %C 41.13; i4 350;

MRd 75.94. Found: 5H 5.94; %C 41.39; W 360; MRd 77.70.


5. CFaBrCFCICH2CHBir(CH3)aSIC I (XIV)

a. With Pyridine

XIV (50 g.) and pyrldine (40 g.) were combined in a 100

ml. distilling flask. A grey precipitate formed immediately. The

filtrate was distilled at atmospheric pressure to remove the excess

pyrldlne. The residue was distilled under vacuum. Hone of the re-

sulting fractions could be Identified as each came over a wide temp-

erature range.

b. with Alcbiollc Potasslum Hydroxide

A solution of ethanol (200 ml.), potassium hydroxide (7 g.)

and XIV (25 g.) was heated on a steam bath for 2 hours. The salt

was filtered off and the filtrate worked up in the usual manner,

Distillation of the crude organic layer resulted in several fractions,

none of which could be Identified.

c. With Aqueous Base

A solution consisting of 50 g. of XIV and an excess of

aqueous potassium hydroxide was heated and stirred for 3 hours. The

mixture was neutralized with dilute hydrochloric acid and the organic

layer worked up in the usual manner. The forerun contained a material

which crystallized In the distillation head. This material was heated

with a flame and collected In the receiver. This solid was sol uble









in hot water and was benzoic acid. The principal fraction, 15 g.,

came over at 165-170 /1 vm. The infra-red spectrum of this material

was identical with.II.

It Is evident from this reaction that the chlorosilane, XIV,

was contaminated with benzoic acid, a by-product of the Initiator.

6. The Addition Products of Dlvlnyldlmethylsllane

a. With Alcoholic Base

The addition products were treated with an excess of alcoholic

base at room temperature. The salt was filtered and the filtrate

worked up In the usual manner. A nwterial with the following physical

properties was isolated. b.p. 73.8-74/ /8.5 mnn. n20 1.4445; dao

1.344. These constants were identical to those for the lower belling

fraction of the addition reaction. Furthermore, the Ag eq. analysis

was also the same, 162. The Infra-red spectrum of this material

indicated that hydrogen bromide did split out and that the product

was contaminated with some type of carbonyl compound, very likely

benzolc acid.

b. With Zinc and Alcohol

The addition mixture was reacted with an excess of zinc and

ethanol. The reaction mixture was worked up in the usual manner and
o
a material with the following properties isolated. B.p. 136-137 t

na2 I.4000; de0 0.979. This material was identified as being XVI.

Anal. Calcd. for CgH,13FSIO: Ind 47.92; %C 49.461 %1 6.74. Found:

I'd 48.15; %C 09.78; 5H 6.97.

Infra-red absorption:

3.45(m); 5.54(s); 6.26(w); 6.95(mw); 7.10(m); 7.75(s); 8.06(s);





-41-


8.45(s); 8.55(s); 9.35(s); 9.90(m); 10.05(m); 10.25(m); il.15(ms);

12.00(brd s); 13.10(w smear); 14.50(w smear).

7. The Products obtained front the addition to Diallyldlnethylsllane
a. With Zinc and Ethanol
These reaction products were treated with an excess of zinc

and ethanol. The reaction mixture was worked up In the usual manner.

A fraction, 5 g., with the following properties was Isolated. B.p.

38-42 /3 nm.; n20 1.4300j d20 1.077. This material was believed to
be XX. Anal. Calcd. for CIoHisFSi10: MRd 53.74; %C 54.60; ,H

6.82. Found: MRd 52.65; %C 54.10; %H 6.95.
Infra-red absorption:

3.42(s); 5.56(s); 5.67(m); 6.10(vw shd); 6.16(ms); 6.91(m))

7.05(m); 7.30(w); 7.75(s); 7.87(w); 7.94(s); 8.07(w); 8.45(m);
9.25(s); 10.13(s); 11.95(s); 12.33(s); 12.75(s); 1415(w).
8. CF,OrCFCICHCHDrSI (CH)i1 (VIII)
a. ulth Zinc and Alcohol

A solution of VIII (50 g., 0.13 mate), methanol (100 ml,) and
excess zinc was stirred and refluxed for 3 hours. The reaction

mixture was worked up In the usual manner and two products Isolated.
The lower boiling fraction, 5 g., was Identified as being X and had

the following properties: b.p. I14; n3 1.3790; d23 0.962. Anal.
Calcd. for C6H13F3SI: M Rd 43.77; C 46.70; PH 7.11. Found: MRd

43.60; %C 46.60; P 7.25.
Infra-red absorptions:

3.38(s); 5.52(s); 6.94(is); 7.05(m); 7.45(w)j 7.70(s); 7.81(s);









7.90(s); .io0(s); .45(s)j 3.55(s); 9.35(8); 10.05(s); II.l(s);

12.00(s smear); 12.65(m); 13.25(s)i 13.50(s); lh.50(s).

The second fraction, 15 g., had the following properties: b.p.
O
92 /60 rim.; n" I.4275 da3 1.297. This material was IX. Anal.

Calcd. for C6fIZBrFlSI: H d 51.L5; jBr 30.35. Found: MRd 51.50;

Br 31.02.

Infra-red absorptions:

3.36(m); 5.52(s); 7.05(..); 7.4(s); 7.70(s); 7.Ci(s); 7.98(s);

.l10(s); G.35(s); e.C2(w); 9.00(m); 9.18(s); 10.00(2); II.IC(m);

11.75(s brd); 13.35(m); 14.45(n).


C. MISCELLANEOUS REACTIONS

I. Reaction of CFg8rCFCICHCHSI (QC3)3 with excess Base


A solution of the sllane (29.5 g., o.I mole) and a large excess

of ethanollc potassium hydroxide was heated on a steam bath for several

hours. The mixture was worked up In the usual n nner and a fraction
o
b.p. 99-100 Isolated. This material had the following properties:

n2 1.3990; d2a 1I.,70. A gas chrometogram showed two almost equal

peaks. This material was undoubtedly a mixture of bexamethyldlslloxane

and CF8BrCFCCIH=CHa since the boiling point reported for these cam-
0
pounds are both about 99 The Infra-red spectrum of the material In

question showed peaks which were characteristic of both components.

2. Reaction of CFaBrCFCICHgCHBrS (CH3)3 with Concentrated

Sulfuric Acid


A mixture of 100 ml. of concentrated sulfuric acid and 25 g.




-43-


O
of VIII was heated at 105-120 for 3 hours. This mixture was poured

into crushed Ice and the aqueous layer extracted with ether. The

ether extracts were combined with the organic layer, dried and

distilled. The principal fraction, 15 g., came over at 163-165 /

Imm., and had the following properties: n25 1.4820; das 1.7950.

This material was the disiloxane II. Anal. Calcd. for II Ag eq.

123.2; found: 123.6.

The residue was extracted with hexane and treated with norlte.

A clear viscous yellow oil remained. This material was probably

the product of the reaction of two or possibly all three methyl groups

with sulfuric acid.

3. reaction of CFa2rCFCICH2CH=CH2 with Zinc and Alcohol

(Proof of Structure)


The olefin (25 g.) was dropped into a refluxing slurry of

zinc and methanol. The resulting azeotrope was collected as formed.

This mixture was washed with cold water and the organic material

distilled. A fraction with the following properties was Isolated.

B.p. 42 ; n23 1.3420; d23 1.0350. The infra-red spectrum of this

material was identical to that reported for CF2gCFCHgCH=CI2.

D. PREPARATION OF STARTING MATERIALS

I. Divinyltetramethyldlsiloxane

A mixture of vinyldlmethylethoxysilane (300 g.), benzene

(700 ml.), water (100 mi.) and 0.5N hydrochloric acid (15 ml.)

was heated and efficiently stirred for 12 hours. The benzene and

water were azeotroped off and the residue distilled. The desired









0
product, b.p. 138-142 vas obtained In a 90% yield (196 g.).

2. Vinyldlmethylchlorosilane

Vinyl magnesium bromide (S moles), prepared by the addition

of 10 moles of vinyl bromide to 10 moles of rmgneslum in 6 liters of

tetrahydrofuran, was slowly added to 3 moles of dilethyldlchloro-

sllane. The mixture was refluxed overnight and the salt filtered

off. The filtrate was distilled to yield 200 g. of product b.p.
0
80-90.

3. Divinyidimethys Ilane

This material was prepared In the sawe manner as the

vinyidimethylchlarosilane except that two moles of the Grignard

reagent was used per mole of dimethyldlchlorosi lane.

4. Olallyldimethylsilane

Allyl magnesium chloride was prepared by the addition of

allyl chloride to an excess of magnesium In tetrahydrofuran solvent.

This reagent (2.4 mole) was added to I mole of dimethyldichloro-

sllane. The mixture was refluxed for 10 hours, filtered and the

filtrate hydrolyzed with very dilute hydrochloric acid. A 60%
o
yield of the desired product, b.p. 133-135 79 g., was obtained.

5. Vinylpentamethyldislloxane

A solution of hexamethyldislloxane (.0 g., 0.25 mole),

vinyldimethylethoxysllane (65 g., 0.5 mole), potassium hydroxide

(1I g.) and 200 ml. of ethanol was refluxed for 2 hours. The

mixture was neutralized with hydrochloric acid, dried and distilled.

A 6 S yield, 30 g., 30% canverslon)of the desired product was
obtained. .p. 120
obtained. D.p. 120





-45-



6. CF-BrCFCICICHOr3i (CH3)3 (VIII)

A solution of vinyltri~ethylsllane (100 g.), dlbromlde

(1500 g.) and benzoyl peroxide (10 g.) was refluxed for 10 hours.

The excess dibromide was distilled off and the higher boiling

residue distilled under vacuum. A 90A yield of the adduct was

obtained. B.p. 620/1 m.; n23 1.4630; d23 1.610.









SU-HARY


The addition of CFaBrCFCIBr to a series of alkenyl silicon

compounds was studied. These compounds were vinyldimethylethoxy-

sllane, vinyldlmethylchlorosilane, divinyldlmethylsllane, allyl-

trimethylsllane, diallyldlmethylsllne, vlnylpentamethyldlslloxane

and 1,3-dlvlnyl-1,l,3,3-tetremethyldislloxane. A mixture of products

was obtained when two unsaturatlon sites were present as in 1,3-

dlvlnyl-l1,,3,3-tetramethyldislloxane. This mixture consisted of

the product of the addition to one vinyl group and the product of

the addition to both vinyl groups.

An Interesting phenomenon was observed In the addition of

CFaBrCFCIBr to allyltrlmethylsilane. The olefin, CFDBrCFCICIiCH-CHa

and bromotrimethylsilane were the products of this reaction. A

mechanism Involving the Intermediate free radical was postulated

to account for these products. It was further observed that the

addition of the same haloalkane to diallyldimethylsilane did not

result in the formation of the cleaved products. Only a small portion

of the reaction mixture was Identified. This material was the result

of the addition to one allyl group In which hydrogen bromide split

out.

All attempts to dehydrohalogenate the addition products of

the dislloxanes resulted In cleavage of the dislloxane bond. It was

felt that some dehydrohalogenation occurred since potassium bromide

was present in the reaction mixture. However, when the mixture was

neutralized, several different disiloxanes were undoubtedly reformed.

-46-





-47-




Unusual results were obtained when the addition products were

treated with zinc and alcohol. Along with the expected dehalogenated

product, a material was isolated in which replacement of the re-

maining 0( -bromine with hydrogen had occurred. This reduction was

somewhat surprising In view of the ready formation of CF2=CFCH2CHgBr

from CF~8rCFCICH2CHZBr without evidence of reduction.

Concentrated sulfuric acid selectively cleaved a methyl group

from CF2BrCFCICHaCHOrSi(CH3)3, The resulting sulfate ester readily

hydrolyzed to the symmetrical dislloxane.









BIBLIOGRAPHY


I. Butler and Angelo. J. Am. Chgn. Soc. 29, 3128(1957).

2. Durkhard. J. Am. Chem. Soc. 2, 1078-O0(1950).

3. Freldlander. p. IFl Abstracts of Papers, 133rd Mteeting of

of the American Chemical Society, San Francisco, Calif.,

April, 1959.

4. Fuson and Zlegler. J. Org. Chem. II, 510-12(1946).

5. Gillmln. Haster's Thesis, University of Florida,(1954).
6. Kharasch and Fuchs. J. Or. Chem. j12 97-100(19L4).

7. Kharasch, Kuderna and Urry. J. Or.2 Chjm. 1_, 895-902 (1948).
C. Kharasch, lcBay and Urry. J. Am. Chem. Soc. M, 1269-74 (1948).

9. Kharasch, Relnimth and Urry. J. An. Chem. So. Soc, 1100 (1949).

10. Kharasch, Urry and Kuderna. J. Org. Cham. 1J, 248-53 (1949).

II. Lllyqulst. PhD Dissertatlon, University of Florida, (1955).

12. Sommer et al. J. Am. Chea. Soc. 76, 801-3 (1954).

13. Sommer, Darle and Gould. J. Am. Chen. Soc. 70, 2C69-72 (1948).

14. Soaer, Tuler and Whitmore. J. Am. Chen. Soc. Q0, 2872-4 (194)).

15. Tarrant, Dyckes, Nlorrls and O'Conner. p. 471 Abstracts of Papers,
128th fleeting of the American Chemical Society, Minneapolls,

Minn., Sept., 1955.

16. Tarrant and Gillln. J An. Chum. Soc. 36, 5423 (1954).

17. Tarrant and Lllyquist. J. Am. Ch_'. Soc. 1., 3640 (1955).
IC. Tarrant and Lovelace. J A. Chu. Soc. M7 3640 (1955).

19. Warrick. J. Am. Chm. Soc. 6Q, 2455 (1946).









BIOGRAPHICAL NOTES


Charles Tomasino was born on March 14, 1931, In Tampa, Florida

where he attended local schools and was graduated from Thomas Jeffer-
son High School In June, 1948.

He entered the University of Florida In July, 1948, and re-

ceived his BS degree In chemistry In June, 1952. After graduation

he Immediately was called Into military service where he spent two

years as a Truck Officer in the U. S. Army Transportation Corp. The

author was employed by Peninsular Chem Research, Inc. for one year as

a research chemist before entering graduate school. He received his

Master of Science degree In chemistry in January, 1957.

At the University, he held the position of research assistant

on a project sponsored by the Office of the Quartermaster General, U.S.

Army, under the direction of Dr. Paul Tarrant.

The author Is married, has one child and Is a member of the American

Chemical Society, Alpha Chi Sigma and Gamma Signm Epsilon.









This dissertation was prepared under the direction of the
Chairman of the candidate's Supervisory Comlttee and has been
approved by all members of the committee. It was sdettted to the
Dean of the College of Arts and sciences and to the Grad ite Cwmncil
and was approved as partial fulfillment of the requlrementa for the
degree of Doctor of Philosophy.


January 31, 1959


Dean, College of Arts and Scleaces


Dean, Graduate School
SUPERVISORY COH'ITTEE:



Cha r an






-J // "
j^ c._.., J~




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