A discharge flow reactor with laser magnetic resonance and resonance fluorescence detection axes is used to measure the rate constant for the reaction of OH and HO2 radicals by measuring the decay of OH in excess HO2 under pseudo-first-order conditions. Particular care is taken to reduce impurity O and H atoms to low levels since their presence leads to an underestimate of the rate constant. The rate constant is measured to be (8.0-2.0+3.0) × 10-11 cm3 molecule-1 s-1 at 298 K and 2 Torr after a small (3%) correction is made for the impurity atoms. It is argued that recent experimental and theoretical results indicate that the reaction mechanism is likely dominated by attack at the hydrogen end of HO2 and that the reaction is unusually fast due a long-range attractive interaction.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry