MECHANISTIC STUDY OF THE GAS-PHASE REACTION OF CH2FO2 RADICALS WITH HO2

Fourier transform infrared spectroscopy was used to identify CH2FOOH a nd HC(O)F as products of the gas-phase reaction of CH1FO2 radicals wit h HO2 radicals. At 700 Torr and 295 +/- 2 K, branching ratios for the CH1FOOH forming channel, k(1a)/k(1) = 0.29 +/- 0.08 and the HC(O)F cha nnel, k1b/k1 = 0.71 +/- 0.11 were established. Quoted errors are 2 sta ndard deviations together with our estimate of systematic uncertaintie s. This result is discussed with respect to previous literature data a nd to computer models of atmospheric chemistry. As part of this work, the reactivity of Cl atoms towards CH2FCl and CH2FOOH was investigated ; rate constants of k(Cl + CH2FCl) = (1.1 +/- 0.1) X 10(-3) and k(Cl CH2FOOH) = (1.5 +/- 0.5) X 10(-3) cm(3) molecule(-1) s(-1) were deter mined.