Liquid phase kinetic study of the formation and decomposition of methylsulfonyl and cyclohexylsulfonyl radicals in the cyclohexane–MeSO 2 C1‐SO 2 System at 150°

The thermally and radiolytically induced chain decomposition of methanesulfonyl chloride (MeSO 2 Cl) in liquid cyclohexane (RH) was studied at 150°C. The main products, chlorocyclohexane, sulfur dioxide, and methane, are formed in almost equal yields, and a relatively small amount of methyl chloride is also observed. The formation and addition of SO 2 strongly inhibit the chain decomposition reaction. By kinetic analysis it is shown that the formation of the main products can be explained only in terms of a mechanism that postulates the decomposition of MeSO 2 , and that the alternative mechanism of methane and SO 2 formation via the methanesulfinic acid is inconsistent with the kinetic behavior of the system. For the reactions Me + MeSO 2 Cl → MeCl + MeSO 2 (2b), Me + RH → MeH + R (4), and Me + CCl 4 → MeCCl 4 → MeCl + CCl 3 (15b) the following rate constant ratios are determined; k 2b / k 4 =2.17±0.20 and k 2b / k 15b =2.63±0.52. For the reactions R + MeSO 2 Cl → RCl + MeSO 2 (2a) and R + CCl 4 → RCl + CCl 3 (15a), k 2a / k 15a is equal to 1.55±0.05. In addition the equilibrium constant K 7 for the reaction R + SO 2 ⇄ RSO 2 (7) is estimated as being equal to (9.4±3) × 10 3 mole/l.