Reactions of S Atoms with Dimethyl Sulfide and Thietane

Article abstract of DOI:10.1021/ja00335a011

S(¹D) atoms react with CH3SCH3 to generate elemental sulfur and CH3SSCH3 as major primary products along with small amounts of C2H6, and with to give and C2H4 in comparable yields.The reactions of ground-state S(³P) atoms with these substrates afford the same products, but the overall product recoveries are smaller, and in the case of , the C2H4/ ratio is decreased.It is proposed that the primary adducts are vibrationally hot S₀ and T₁ state thiosulfoxides which then may isomerize to the corresponding disulfide, fragment via C-S cleavage, or undergo collisional deactivation to the grand state.Bimolecular reactions between two thermalized ground-state thiosulfoxide molecule and an S₂-S₇ radical lead to regeneration of the substrate and to the formation of S₃-S₈ which ends up as elemental sulfur.The latter reactions predominate for the case of S(³P) addition to both substrates.From competitive experiments in the presence of C3H6 the following rate parameters have been drived: k(S(³P) + CH3SCH3) = (5.0 +/- 1.2) x 10¹⁰ exp<(0.84 +/- 0.24)/RT> M^-1 s^-1 and k(S(³P) + = (8.2 +/- 1.9) x 10¹⁰ exp<(0.75 +/- 0.20)/(RT)> M^-1 s^-1.The characteristic C-H insertion reaction with S(¹D) atoms was not observed.