Spectrophotometric and kinetic study of histidine in aquo-organic medium

The effect of ionic strength and H+ ion concentration on rate of reaction was confirmed. The varying concentrations of substrate and oxidant showed significant effect on rate of reaction. The observed values E a, ΔG and ΔH were determined as KJ mol^-1 and ΔS as JK^-1 mol^-1 respectively. There was good agreement between the observed and calculated rate constants with respect to various effects. The catalytic effect of bromide and ferrous ion were examined in detail and a suitable mechanism has been proposed with the experimental results.