Reactions in clay media: photooxidation of sulfides by clay-bound methylene blue

Photooxidation of dialkyl and alkyl aryl sulfides to the corresponding sulfoxides with clay-bound methylene blue is studied in acetonitrile. A significant increase in sulfoxide/sulfone ratio and a marginal increase in cooxidation of a second sulfide molecule are observed. The results are explained in terms of a suitable mechanism involving persulfoxide and thiadioxirane intermediates.