Chromium(VI) oxidation of methyl phenyl sulfide–kinetic and mechanistic approach

Abstract

The kinetics and mechanism of oxidation of methyl phenyl sulfide (MPS) with bispyridinesilver(I) dichromate (BPSDC) leads to the formation of the corresponding sulfoxide. The reaction is first order with respect to (BPSDC) and a Michaelis–Menton type of kinetics followed with respect to (MPS). The reaction is catalysed by hydrogen ions. The decrease in dielectric constant of the medium increases the rate of the reaction. Addition of sodium perchlorate increases the rate of the reaction appreciably. Addition of acrylonitrile rules out the possibility of radical pathway mechanism. The reactions has been conducted at four different temperatures and the activation parameters were calculated. From the observed kinetic results a suitable mechanism was proposed.

Keywords:

• Methyl phenyl sulfide
• Kinetics and mechanism
• Kinetics
• Oxidation
• Bispyridinesilver(I) dichromate

Acknowledgements

The authors wish to express their sincere thanks to Prof. K. Pandiarajan, Head of the Department of Chemistry, Annamalai University and Prof. S. Kabilan, Department of Chemistry, Annamalai University and also the authorities of Muthayammal College, Rasipuram, for their keen interest and encouragement in this study.