RESUMEN
A gas-phase kinetics study of the atmospherically important reaction between Cl2 and dimethyl sulfide (DMS) Cl2 + CH3SCH3 --> products (1) has been made using a flow-tube interfaced to a photoelectron spectrometer. The rate constant for this reaction has been measured at 1.6 and 3.0 torr at T = (294 +/- 2) K as (3.4 +/- 0.7) x 10(-14) cm3 molecule(-1) s(-1). Reaction (1) has been found to proceed via an intermediate, (CH3)2SCl2, to give CH3SCH2Cl and HCl as the products. The mechanism of this reaction and the structure of the intermediate were investigated using electronic structure calculations. A comparison of the mechanisms of the reactions between Cl atoms and DMS, and Cl2 and DMS has been made and the relevance of the results to atmospheric chemistry is discussed.