Reactivity of H 2O 2 with radiation produced free radicals: Steady state radiolysis methods for estimating the rate constants

Abstract

A new steady state radiolysis method for the determination of the rate constants of reaction of H 2O 2 with solute radicals derived by reaction with radiation produced OH radicals is described. The values so obtained are comparable with the ones obtained by the method described by Soylemez and Balkas in the past. A method similar to the latter has been employed to determine the rate constant of reaction of H 2O 2 with solute radicals derived from e - aq reaction. In the case of the (CH 3) 2 COH radical which can be generated by either reaction of OH with isopropanol or e - aq with acetone, the three methods give values agreeing with each other within ± 15% (viz. 2.7 ± 0.4 × 10 5 dm 3 mol -1 s -1). The reaction of the solute radicals with H 2O 2 is considered in the light of known one-electron redox potentials, and the limitations of the applicability of the methods described here are discussed.