Temperature dependent rate constants for the gas-phase reaction between OH and CH3OCl

The reaction between OH radicals and CH3OCl 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 CH3OCl. The Arrhenius expression for the rate constant is given by k(4)(250-341 K) = (2.4 +/- 0.8) x 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 CH3OCl in the polar stratosphere.