Fluoroalkyl Derivatives of Sulphur

Haran, Gerrard (1972) Fluoroalkyl Derivatives of Sulphur. PhD thesis, University of Glasgow.

Abstract

The work of this thesis is concerned with the preparation, identification and some reactions of bis(trifluoromethylthio)alkanes and -fluoroalkanes and some reactions of trifluoromethylsulphur(Vl) chloride tetrafluoride. Bistrifluoromethyl disulphide reacts in a Pyrex vessel with olefins to give adducts which are best described as formed by attack of CF3S radicals on the olefin. Ethylene gives CF3SCH2CH2SCF3; propene CF3SCH2CH(CH3)SCF3; tetrafluoroethylene CF3S(CF2CF2)2SCF3 and CF3S(CF2CF2)n SCF3(n large); hexafluoropropene CF3S[CF(CF3 )CF2]nSCF3 (n = 1,2); 1,1-difluoroethylene CF3S(CF2CH2)SCF3 (n = 1-6); trifluoroethylene CF3S(CF2CFH)nSCF3 (n= 1-7); chloro-trifluoroethylene CF3S(CF2CFCl)nSCF3 (n = 1-4) and also CF3SCF2CFClCF3 and CF2CFClCF2CFClS; tetrachloroethylene CF3SCCl2CCl2SCF3,CF3SCCl=CCl2 and CF3SCCl2 CCl3. The infrared spectra of these adducts have been investigated but structure elucidation is obtained by a detailed investigation of the 19F n.m.r. and mass spectra which are discussed at some length. An attempt is made to rationalise the mode of formation of the various isomers in the polymeric adducts in the light of current thinking on free radical addition to unsymmetrical olefins. The reaction of CF3S [CF(CF3)CF2]SCF3 with chlorine monofluoride gives the new bis-sulphur(IV) compound CF3SF2CF2CF(CF3)CF(CF3)CF2SF2CF3 whose structure is established by 19F n.m.r., i.r. and mass spectra and by elemental analysis. The reaction of some of the adducts with liquid chlorine fails to give the S(lV) dichlorides. Trifluoromethylsulphur(Vl) chloride tetrafluoride adds to unsaturated carbon-carbon linkages under the influence of ultraviolet light in a manner best described by addition of CF3SF4 radicals. Ethylene gives CF3SF4CH2CH2Cl; propene CF3SF4CH2CHClCH3; tetrafluoroethylene CF3SF4CF2CF2Cl; hexafluoropropene CF3SF4CF(CF3)CF2Cl and CF3SF4CF2CFClCF3 (trace); 1,1-difluoroethylene CF3SF4CH2CF2Cl; trifluoroethylene CF3SF4CFHCF2Cl; chlorotrifluoroethylene CF3SF4CF2CFCl2 and CF3SF4(CF2CFCl)2Cl; acetylene CF3SF4CH=CHCl. The 19F n.m.r. spectra of the adducts establishes the trans structure about the sulphur atom. Some of the reactions also produce a compound which is thought to be CF3SF4 SF4CF3. The ultra-violet light induced reaction of CF3SF4Cl with hydrogen is also thought to produce CF3SF4SF4CF3 with HCl produced as a co-product, but the reaction of CF3SF4Cl with oxygen fails to give the oxide or peroxide, CF3SF4OSF4CF3 or CF3SF4OOSF4CF3, under the reaction conditions used. CF3SF4Cl decomposes in the presence of mercury to give only CF3Cl and SF4 and a scheme is postulated to try to account for the specificity of the products observed.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1972
• Depositing User: Enlighten Team
• Unique ID: glathesis:1972-78595
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 28 Feb 2020 12:09
• Last Modified: 28 Feb 2020 12:09
• URI: https://theses.gla.ac.uk/id/eprint/78595