Oxidation studies with peroxomonophosphoric acid. II. A kinetic and mechanistic study of dimethyl sulfoxide oxidation in acid and alkaline media

Abstract

The kinetics of dimethyl sulfoxide (DMSO) oxidation by peroxomonophosphoric acid (PMPA) in aqueous medium a t 308 K and I = 0.4 mol/dm3 follow the rate expressionsIn the pH range from 0 to 2, where k l and kz are 5.092 X 10-1 dm3/mol sec and = 0, respectively; in the pH range from 4 to 7, where k2 = 8.127 X lo-" and kn = 2.90 X and dm3/mol sec;in the pH range from 10 to 13.6, where k4 N 0, and k:, = 3.08 X The reaction is interpreted in terms of mechanisms involving an electrophilic and a nucleophilic attack of the peroxomonophosphoric acid species, respectively, in acid and alkaline regions, on the sulfur atom of the sulfoxide molecule giving rise to SNZ-type transition states followed hy oxygen-oxygen bond fission to form the products. dm3/mol sec.

Electron transfer to trans‐dihydroxotetraoxoosmate(VIII). II. Kinetics of the oxidation of dimethylsulfoxide in aqueous alkaline media

“…Dimethylsulfoxide is an effective two-electron transferring agent, and a number of its oxidation reactions are known to involve a direct twoelectron change [13,14]. A value of -0.23 V has been reported for the dmso/dmsoz couple [15].…”