KINETICS OF THE OXIDATION OF METHYL PHENYL SULFIDE BY HYDROGEN PEROXIDE IN THE PRESENCE OF HYDROCARBONATE ANION

The oxidation of methyl phenyl sulfide in water and water.alcohol mixtures takes place both by a noncatalytic mechanism and with the participation of hydrogen peroxide as catalyst; in the presence of ammonium hydrocarbonate it takes place by a mechanism involving HCO4^ -as a more active oxidant than hydrogen peroxide (>100 times). In water.alcohol media (ethylene glycol, isopropyl alcohol, tert-butanol) the rate decreases in the order H2O > EG > IPA > TBA. The reactivity of organic sulfides varies in the following way: MeSPh ≈EtSPh << Et2S. The results were interpreted from the standpoint of a molecular mechanism of oxidation of the sulfide with H2O2 and HCO4^ -through a polar transition state, containing the HOX molecule (X = H, OH, OR) as acid.base catalyst.