Reactions of OH Radicals with Methanethiol, Dimethyl Sulfide, and Dimethyl Disulfide in Air

Article abstract of DOI:10.1021/j100236a029

Photooxidations of CH3SH, CH3SSCH3 (DMDS), and CH3SCH3 (DMS) in air were performed with alkyl nitrites as sources of OH radicals.Sulfur-containing final products are SO2, CH3SO3H (methanesulfonic acid), and a little H2SO4 in all cases.CH3SH reacts with OH to form an adduct, which further reacts with alkyl nitrites to give CH3SNO (methyl thionitrite) and the corresponding alcohols.CH3S radical produced by photolysis of CH3SNO gives final products.DMDS also reacts with OH via addition followed by rapid cleavage of the S-S bond, resulting in CH3S and CH3SOH.Reaction of DMS with OH can be explained by both addition and abstraction.In both cases the CH3S radical is the main intermediate which produces final products.The reaction of the CH3S radical with O2 proceeds via addition and gives HCHO + SO2 or CH3SO3H as final products.The rate constant ratios of CH3S with NO and O2 were obtained to be ca. 2 x 1E3, which is about one-tenth of that for CH3O.