Electron spin resonance studies of H2S, CH3SH, C2H5SH, L-cysteine, aqueous solutions of H2S, D2S, CH3SH, CH3SD, and L-cysteine, and L-cysteine in aqueous hydrogen peroxide ultraviolet irradiated at 77°K have been made. The primary photochemical process established for each of these compounds is cleavage of the sulfur-hydrogen bond to yield a hydrogen atom and the corresponding thiyl free radical. For methanethiol in water, the free radicals -CH3 and • CH2SH were identified and evidence that -CH2SH did not come from a primary photochemical process was obtained. Hydroxyl radicals from the photolysis of hydrogen peroxide yielded thiyl free radical by abstraction of hydrogen atom from the sulfhydryl group of L-cysteine.

No abstract

No abstract