Determination of the rate constant and of product branching ratios in the reaction of CH₃O₂ with OCl between 233 and 300 K

The reaction CH 3 O 2 + OCl→prod (1) has been investigated in the temperature range 233–300 K using discharge flow mass‐spectrometric technique. A rate constant k 1 (300 K) = (2.5±0.3) 10 −12 cm 3 molecule −1 s −1 has been obtained observing the pseudo‐first‐order decay of CH 3 O 2 radicals. The observed temperature dependence is described by k 1 (233–300 K) = (2.0±0.1)10 −12 exp((80±50)/ T )cm 3 molecule −1 s −1 . The reaction channel (1a) CH 3 O 2 + OCl→CH 3 OCl + O 2 leading to CH 3 OCl formation was identified and found to be negatively temperature dependent with k 1a (233–300 K) = (1.5±0.3)·10 −14 exp ((920±200)/ T )cm 3 molecule −1 s −1 . It is shown that HCHO and HOCl result from the secondary reaction of OCl with CH 3 O.