Catalysis and mechanistic study of Ru(III) and Os(VIII) on the oxidation of taurine by BAT in acid and alkaline media: a kinetic modeling

Abstract

The study of oxidation kinetics of drug molecules is of much noteworthy in order to understand their mechanistic chemistry in redox systems. Taurine, being a potent drug molecule, has a wide range of activities in biological system. Therefore, the kinetics of oxidation of taurine (TAU) by bromamine-T (BAT) in HCl medium, catalyzed by Ru(III) and in NaOH medium, catalyzed by Os(VIII) has been investigated at 313 K. The rate law in acidic medium is: rate = k[BAT] t [TAU]0[Ru(III)]0.95[H+]−0.67. But, it takes the form, rate = k[BAT] t [TAU]0.46[Os(VIII)]0.89[OH−]−0.53 in basic medium. Addition of halide ions and p-toluenesulfonamide had no significant effect on the rate in both the cases. Decrease in dielectric constant of medium decreases the reaction rate in both the media. The conjugate acid, CH3C6H4SO2NHBr (TsNHBr), is assumed to be the oxidizing species in both the media. Equilibrium and decomposition constants have been evaluated in each case.