Rate constant of the reaction between CH3O2 and OH radicals

The rate constant of the reaction(R1) OH + CH 3 O 2 → products has been measured at 294 K by simultaneous coupling of Laser Induced Fluorescence (LIF) and cw-Cavity Ring Down Spectroscopy (cw-CDRS) to laser photolysis. OH radicals were generated by 248 nm photolysis of either H2O2 or O3 in the presence of H2O, CH3O2 radicals were generated simultaneously by photolysis of CH3I and their absolute concentrations were obtained by cw-CRDS. OH decays were measured under excess CH3O2 concentrations and a very fast rate constant of k1 = (2.8 ± 1.4) × 10−10 cm3 s−1 was found independent of pressure at 50 and 100 Torr helium.