Submicrosecond pulse radiolysis conductivity measurements in aqueous solutions—II: Fast processes in the oxidation of some organic sulphides

Abstract

Successful application of a submicrosecond pulse radiolysis conductivity technique with a time resolution of 50 ns in aqueous solutions is demonstrated for a number of fast processes which occur during the OH· radical induced oxidation of some organic sulphides. The reliability of the technique has been tested with well-known systems, i.e. the neutralization reaction H + aq + OH - aq→ H 2O and the conversion of the neutral OH· adduct to 1, 4-dithia-cyclohexane into the intramolecular radical cation complex ▪. New observations on the submicrosecond time scale include the identification of a molecular radical cation, R 2S +, from tetrahydrothiophene and diethylthioether, and a nonionic species in the reaction of OH· with di-tert-butylthioether, probably a (R 2S) 2(OH)· complex. The new results lead to a modified, more general overall mechanism for the OH· induced oxidation of organic sulphides.