Kinetics and mechanism of the oxidation of thiocyanate ion by di-m-oxo-tetrakis(1,10-phenanthroline)-dimanganese (III,IV) ion in acid medium

Abstract

The kinetics of oxidation of thiocyanate ion by di-m-oxo-tetrakis(1,10-phenanthroline)dimanganese(III,IV) perchlorate in acid medium has been investigated. The reaction follows first order in both the oxidant and the reductant. The reaction is catalysed by hydrogen ion and the rate dependence given as k2 = a + b[H+]. The reaction rate is not affected by changes in the ionic strength and dielectric constant of the reaction medium. The reaction did not induce polymerization of acrylamide and the presence of NO3- or HCOO- had no effect on the rate. A plausible mechanism involving proton coupled electron transfer (PCET) is proposed.

Key words: Kinetics, mechanism, oxidation, thiocyanate, di-m-oxo-tetrakis(1,10-phenanthroline)-dimanganese (III,IV)


(Global Journal of Pure and Applied Sciences: 2002 9(1): 105-112)