Reaction of OH with Dimethyl Sulfide. 2. Products and Mechanisms

The technique of pulsed laser photolysis/pulsed laser-induced fluorescence was used to determine products of the following reactions: OH + CH 3 SCH 3 → products (1) and CH 3 S(OH)CH 3 + O 2 → products (5). The non-adduct-forming channel of reaction 1 was observed to proceed via hydrogen abstraction (branching ratio, Φ abs = 0.84 ± 0.26) at 298 K. Direct formation of CH 3 S from reaction 1 was not observed (Φ CH 3 S < 0.04). A small channel for producing CH 3 and CH 3 SOH in the non-adduct-forming route could not be ruled out. HO 2 was found to be produced from reaction 5 with a yield of 0.50 ± 0.15 at 234 and 258 K. An upper limit for the production of OH from reaction 5 was determined to be Φ OH < 0.05. The atmospheric implications of the results from this and the accompanying paper are discussed.