Unstable intermediates. Part 179. Electron spin resonance studies of radicals formed in irradiated organic sulphides and disulphides

Abstract

Various organic sulphides, including dimethyl and di-t-butyl sulphide and methionine, together with disulphides, including dimethyl and dibutyl disulphides, cystine and lipoic acid have been exposed to ⁶⁰Co γ-rays at 77 K, both in the pure state and in various solvents. E.s.r. and, in selected cases, optical spectra of the resulting intermediates are reported and discussed. In particular, the reaction R₂S˙⁺+ R₂S → R₂S–SR₂⁺ is considered and it is suggested that certain species, previously identified as R₂S˙⁺, are better identified as R₂S–SR₂⁺. The structure of species having g values close to 2.058, 2.025, and 2.001 is also discussed.