Kinetic studies of oxidation of secondary amines by chloramine-T in aqueous perchloric acid medium catalyzed by Ru(III)

The kinetics of ruthenium(III) catalyzed oxidation of the secondary amines-diethylamine, dipropylamine, di-isopropylamine and dibutylamine by chloramine-T (CAT) in aqueous perchloric acid medium has been studied. The reaction rate shows a first order dependence each on CAT, sec. -amine and Ru(III). The reaction rate shows an inverse fractional order dependence on acid concentration. Added halide ions and the reaction product, p-toluenesulphonamide have no effect on the reaction rate. Variation of ionic strength and dielectric constant of the medium has no influence on the reaction. The activation parameters have been evaluated. It was observed that the rate of oxidation of sec.-amine by CAT increases in the order DEA < DPA < DBA < DIPA. Also it was found that Δ H* and Δ S* are linearly related and an isokinetic relationship is observed with isokinetic temperature β as 394 K, indicating enthalpy as controlling factor. Mechanisms consistent with experimental rate law have been proposed.