Kinetics and mechanism of ruthenium(III) catalyzed oxidation of dimethyl sulfoxide by N-chlorosuccinimde in aqueous alkaline medium

The ruthenium(III) catalyzed oxidation of dimethyl sulfoxide by N-chlorosuc cinimide (NCS) in aqueous alkaline medium is found to occur via substrate-c atalyst complex formation followed by the interaction of active species of NCS viz., HOCl and the complex in a slow step to yield the products with re generation of the catalyst. One of the products, succinimide, retards the r ate of reaction. The reaction is first order in [NCS] and [Ru(III)], lower than first order in [DMSO] and of inverse fractional order in [OH]. A suita ble mechanism is proposed and the reaction constants of individual steps in volved in the mechanism have been evaluated.