OH-Radical-Induced Oxidation of Benzene in the Presence of Oxygen: R.+O2⇆ RO2. Equilibria in Aqueous Solution. A Pulse Radiolysis Study

Abstract

The reaction of hydroxycyclohexadienyl radical with oxygen was studied by pulse radiolysis. At room temperature the establishment of the equilibria between the hydroxycyclohexadienyl radical (1), oxygen and the hydroxycyclohexa-dienperoxyl radicals 5-hydroxy-1,3-cyclohexadiene-6-peroxyl radical (3) and 6-hydroxy-1,4-cyclohexadiene-4-peroxyl radical (4), was observed. From the kinetic analysis of the decay of radical 1 at 310 nm overall forward and reverse rate constants of k = 3.1×108 dm3 mol-1 s-1 and k = 1.2×104 s-1 were obtained. From the analysis of the transient spectra and the products of pulse-irradiated solutions it is concluded that in the equilibrium radical 4 is much favoured over radical 3. © 1990, Walter de Gruyter. All rights reserved.