Abstracto

Ruthenium (III) Mediated Oxidation of Thiamine Hydrochloride by PDP in Nitric Acid Medium

Biyyala Sreedhar Rao, M. Anand Rao

Oxidation of thiamine hydrochloride (Vit. B1) by PDP mediated by micro amounts (10-6 mol dm-3 to 10- 4) of Ru (III) in aqueous nitric acid medium has been studied at 25˚C. The reaction is second order in both PDP and Ru (III) concentrations. The order with respect to B1 concentration varies first order to zero order as the vitamin B1 concentration increases, An increase in HNO3 concentration decrease the reation rate. The active species of Oxidant and catalyst are [PDP] and [Ru(H2O)6]3 A possible mechanism is proposed and reaction constants involved have been determined. Ruthenium (III) is an efficient catalyst in many redox reactions involving different complexities due to the formation of intermediate complexes, free radicals and multiple oxidation states of ruthenium PDP is a well Known oxidant in acidic media PDP was act as predominant active species in the concentration range 0.30 – 2.0 moldm-3 of Nitric acid, but it role has not received much attention so far the oxidation of thiamine hydrochloride with alkaline potassium ferricyanide, hypo iodide, chlorite and N-chloro benzene sulphonamide were studied. The literature survey reveals that there were no report on the oxidation of thiamine hydrochloride by PDP the mechanism may be quite complicated due to the formation of different PDP and Ru (III) Complexes in the form of active complexes in nitric acid medium. Hence, we have investigated the Ru(III) mediated oxidation of vit B1 by PDP in order to understand the behaviour of active species of oxidant and catalyst to propose a suitable mechanism