Reactions of tetrathiotetraimide

Abstract

The aims of the work described in this thesis are to study the reactions of tetrathiotetraimide and to attempt to systematise its chemistry. Tetra- thiotetraimide is one of the series of sulphur imides S(_x)(NH)(_8-x) derived from octasulphur. The introduction describes the reported chemistry of all known imides derived from octasulphur up to the time of writing, and their behaviour is discussed in terms of seven reaction types. (i) Addition reactions with organic substrates (ii) Adduct formation with Lewis acids (iii) Hydrogen substitution (iv) Hydrogen abstraction (v) Oxidation to thionylimides (vi) Ring degradation (vii) Ring contraction e.g. to S(_4)N(_3)(^+) or (NSCl)(_3) The behaviour of tetrathiotetraimide has been investigated with four types of compounds; (i) metal halides (Lewis acids), (ii) other compounds containing reactive halogen, (iii) organometallic compounds, and (iv) oxygen compounds (all containing the group 0 ). Two new 1:1 adducts of tetrathiotetraimide with AlBr(_3) and A1C1(_3) are described, these are probably σ adducts via donor nitrogen. Ring contraction from the eight-membered (SN)(_4) ring to (a) the seven-membered ring cation S(_4)N(_3)(^+), and (b) the six-membered (SN)(_3) ring-by reaction with the halogens and several active halogen compounds is reported for the first time. Finally, the preparation of a tetrathiotetraimidolithium derivative, and its use as a possible reaction route to (SNX)(_4) derivatives, is discussed.