Kinetic and mechanistic study of oxidation of 1,2-propanediol by aqueous alkaline solution of N-bromosuccinimide in the presence of aquachloro-complex of ruthenium(III) as homogeneous catalyst

Abstract

Kinetics of Ru(III) catalysis in oxidation of 1,2-propanediol by N-bromosuccinimide in alkaline media has been studied in presence of mercuric acetate as bromide ions scavenger in the temperature range of 30–45 °C. The reaction follows complex kinetics, being first order with respect to both 1,2-propanediol and Ru(III). First order kinetics with respect to NBS at its lower concentrations shifts to zero order at its high concentrations. Variation of both [OH^-] and [KCl] shows a positive effect on the rate of reaction. Negligible effect of addition of succinimide (reduction product of NBS) is observed, while variation of both [Hg(OAc)₂] and ionic strength has no effect on rate of the reactions. Various activation parameters are calculated. The products of the reactions have been identified as acetic acid and formic acid. A suitable mechanism in conformity with the kinetic observations is discussed and rate law derived.