Absolute rates of oxygen(3P) atom reactions with benzene and toluene

The absolute values of the rate constants, k_2, of the bimolecular reactions of ground state oxygen atoms, O(^3P), with benzene and toluene have been determined by a phase-shift chemiluminescence technique using modulated mercury photosensitized decomposition of nitrous oxide to generate O(^3P). The rate constants determined over the temperature interval 298-462°K are given by the Arrhenius expressions k_2(benzene) = (1.09 ± 0.64) x 10^(10) exp(-4.20 ± 0.43 kcal mol^(-1)/RT) and k_2(toluene) = (2.30 ± 0.11) x 10^(10) exp(-3.86 ± 0.04 kcal mol^(-1)/RT) in units of M^(-1) sec^(-1). The uncertainties in A and E correspond to 95% confidence limits.