Kinetics of oxidation of diglycine by bromamine- B in perchloric acid Medium

Abstract

Kinetics of oxidation of a typical dipeptide glycylglycine(GG) by bromamine-B (BAB) has been studied perchloric acid medium at 40°C. The rate shows first order dependence in [BAB])₀ and fractional order in [GG]₀ which tends to zero order when [H⁺] = 0.04 mol dm^-3. The reaction is almost independent of [H⁺] (when [H⁺] < 0.03 mol dm^-3) and inverse fractional in [H⁺]([H⁺] = 0.03-0.08 mol dm^-3). Other effects, like addition of halide ions, benzenesulphonamide, and variation in ionic strength and die-lectric constant of medium have also been studied. A solvent isotope effect, <em>k’</em><img src='http://www.niscair.res.in/jinfo/equation88.gif' border=0>/ k’<img src='http://www.niscair.res.in/jinfo/equation89.gif' border=0> = 1.52 is observed. Proton-inventory studies in - mixtures have been made. The reaction has been studied at different temperatures and a mechanism conforming to the kinetic observations is suggested.