Radiolytic decomposition of methanesulfonyl chloride in liquid cyclohexane. A kinetic determination of the bond dissociation energies D(ME‐SO₂) and D(c‐C₆H₁₁‐SO₂)

Abstract

The gamma radiation induced decomposition of MeS02C1 in cyclohexane (RH) was studied Throughout this temperature range the reaction proceeds by a free between 60 and 150°C. radical chain mechanism. Its propagation is described by the following reactions:The kinetic analysis of the results of the experiments with added SOZ, which were carried out in the temperature range of 80 to 15O"C, gives 14.94 =k 0.92 and 11.91 f 0.82 kcal/mole for D(Me-S02) and D(c-C6H11-S02), respectively. These bond dissociation energies are considerably lower than the gas-phase values, and the possible cause of this difference is discussed. Present results also seem to indicate that D(MeS02-H) does not exceed 95 kcal/mole. Competitive experiments with added tetrachloroethylene result in log kZa (l./mole . sec) = 9.07 & 0.17 -(4.92 & 0.21)/0 where e = 2.303RT in kcal/mole.

Arylazo Sulfones as Nonionic Visible-Light Photoacid Generators

“…As a matter of fact, the BDE of the C−S bond in the methanesulfonyl radical was estimated to be around 18 kcal mol −1 in the gas phase, 40 making the α-scission feasible. 41 The low quantum yield in the acid release (<0.05, Table 1) did not hamper the synthetic applications of the examined PAGs, as demonstrated by the protection of alcohols as THP ethers.…”

Thermochemistry and kinetics of sulfur-containing molecules and radicals

“…The radical HS02 has two isomeric forms H-S02 and HO-8=0 for which by our various rules we can deduce AH,°of -42 ± 4 and -60 ± 3 Real, respectively. Thus the latter will be significantly more stable with an H-OSO bond dissociation energy of 41 Real. Efforts to measure the rate of addition of H atoms to S02 in flow systems have been made difficult by the very rapid wall recombination.57 However, flame studies which have been re-cently reviewed54 indicate a fairly rapid three-body reversible recombination above 1600 K. This would be compatible with the 41-Real bond energy.…”

Accurate predictions of C–SO2R bond dissociation enthalpies using density functional theory methods

“…Due to the experimental difficulties, 8 the C-SO 2 R BDEs have been rarely reported (less than 10 to the best of our knowledge). For example, Horowitz evaluated the bond dissociation enthalpies of MeSO 2 via complex kinetic studies of the radiolysis of MeSO 2 Cl in cyclohexane, 11 and Cornell conducted toluene carrier studies on the pyrolysis of trimethylene sulfone and 2-methylsulfolane to determine the related C-SO 2 R bond strengths. 12 In the present study, we attempt to find out an alternative to evaluate the C-SO 2 R BDEs with the aid of DFT calculations.…”