Homogenous catalysis of Ru(III) for the oxidation of Thiamine by ChloramineT in acidic medium

In this paper we report a nano concentration of ruthenium(III) used as a homogenous catalyst for the oxidation of thiamine (THM) by chloramine T(CAT) alongwith its mechanistic pathway, spectrophotometrically.Such studies are greatly helpful in gaining an insight into the interaction of metal ions through the study of the mechanistic pathway of THM in redox reactions. The reaction followed a pseudo first-order rate constant throughout the variation of CAT in the oxidation of THM. It was observed that the first-order kinetics with respect to [Ru(III)], [THM] and [H+].It is clear from the experiential values of rate constant increase with increased concentration of each reactant. The investigators, thus, concluded that the variations of [p-toluene sulphonamide, PTS] and halide ions have an insignificant effect on the reaction rate. Protonated CAT, TsNHCl, and chloro complex of Ru(III), [RuCl5(H2O)]2−, have been suggested as the reactive species in acidic medium. The stochiometry of the reaction is 1:1 in the presence of catalyst. The two main products, 4-amino-2-methyl-4,5-dihydropyrimidine-5-carbaldehyde and 2-(4-methyl-1,3-thiazol-5-yl)ethanol and 2-(4-methyl-1,3-thiazol-5-yl)ethanol were separated, and identified by column chromatography, TLC and FT-IR. Consequently, the interaction between the complex species and THM is supported kinetic orders of reaction by spectrophotometric verification, positive entropy of activation and the first-order rate constant increased with the decrease in the dielectric constant and increase ionic strength of the medium. The reaction constants involved in the mechanism were computed and the overall activation parameters were evaluated which lend support to the proposed mechanism.