The reactions of hydrogen atoms with bis(trifluoromethyl)disulfide

The reactions of hydrogen atoms produced by the mercury-photosensitized decomposition of H₂ with bis(trifluoromethyl)disulfide has been studied. The rate coefficient for the primary reaction, H + CF₃SSCF₃ → CF₃SH + CF₃S, was determined in competition with the reaction H + C₂H₄S → SH + C₂H₄ to have the value k = (3.0 ± 0.18) × 10¹⁴ exp-(4560 ± 140)/RT] cm³ mol^?1 S^?1. The high A factor can be partially accounted for by assuming free rotation for the two CF₃ groups and the SCF₃ groups about the S—S bond in the transition state. The relatively high activation energy is attributed to inductive and orbital overlap effects. CH₃SH, H₂S, and CF₃SH all react with CF₃SSCF₃ to yield solid complexes which were not explored further.