Temperature Dependent Rate Constants for the Gas-Phase Reaction between OH and CH3OCl

The reaction between OH radicals and CH 3 OCl was investigated by the method of laser-photolysis/resonance fluorescence. Rate constants were obtained directly at several temperatures by monitoring the decay of OH radicals in a large excess of CH 3 OCl. The Arrhenius expression for the rate constant is given by k 4 (250−341 K) = (2.4 ± 0.8) × 10 -12 exp(−(360 ± 100)/ T ) cm 3 molecule -1 s -1 . No pressure dependence was observed between 30 and 300 Torr of argon. On the basis of this kinetic data, the reaction with OH can be considered a relatively unimportant removal process for CH 3 OCl in the polar stratosphere.