Kinetics and mechanism of Ru(III) catalysed oxidation of α-picolines by Ce(IV) in nitric acid medium

The kinetics of oxidation of alpha-picolines by Ce(IV) in the presence of Ru(III) in aqueous nitric acid medium has been studied. The order in [Ce(IV)] was found to be unity and with respect to [picoline] it was fractional. Increase in [Ru(III)] increased the rate of oxidation and order in [Ru(III)] was found to be fractional. The rate of oxidation increased with increase in [H+] and order with respect to [H+] was also fractional. These reactions have been studied at different temperatures and the energy of activation has been determined from which thermodynamic parameters have been evaluated. Isokinetic temperature was found to be much above the range of experimental temperature used. A plausible mechanism consistent with the experimental results has been proposed.