Kinetics and Mechanism of Ruthenium(III)  Catalysed Oxidation of L–Arginine by  Hexacyanoferrate(III) in Alkaline Medium

Garapati Sridevi; Nowduri Annapurna; Parvataneni Vani

Volume : II, Issue : IX, September - 2013

Kinetics and Mechanism of Ruthenium(III) Catalysed Oxidation of L–Arginine by Hexacyanoferrate(III) in Alkaline Medium

Garapati Sridevi, Nowduri Annapurna, Parvataneni Vani

Abstract :

The kinetics of the ruthenium(III) catalysed oxidation of L–arginine by hexacyanoferrate(III) [HCF(III)] was studied spectrophotometrically in alkaline medium at 420 nm. It was found that the reaction is first order with respect to [catalyst] and [hexacyanoferrate(III)]. The reaction showed fractional order dependence on [substrate] and [alkali]. The oxidation product of the reaction was found to be α– keto acid. The anionic species of arginine (Arg–) is considered to be the reactive species.A suitable mechanism involving complexation between Arg– and [Ru(H2O)5OH]2+ was proposed leading to the rate law The activation parameters of the rate determining step Ea, and ?S#, were computed to be 38.03 � 0.72kJ mol–1 and –202.80� 2.16 JK–1mol–1 respectively