Kinetics and mechanism of chloramine-T oxidation of glycolic acid catalysed by PdII complex in alkaline medium

The kinetics of chloramine-T (CAT) oxidation of glycolic acid (GA) using alkaline solution of palladous chloride complex as homogeneous catalyst has been investigated at 308 K. A 1 : 1 stoichiometry has been observed. The reaction shows first-order kinetics at lower [CAT] but at its higher concentration first-order tends to zero order. A first-order dependence of the reaction on both [GA] and [Pd-II] was observed. An increase in the concentration of OH- ions increased the reaction rate, while addition of chloride ions decreased the rate of reaction. Added p-toluene sulphonamide (reduction product of chloramine-T) did not influence the reaction rate while zero effect of variation of ionic strength of the medium was observed. The overall activation parameters have been calculated from the Arrhenius plot. Mechanistic steps are suggested and the rate law derived was found in agreement with the observed kinetic results, stoichiometry and the reaction products.