Computational study of the reaction of the methylsulfonyl radical, CH 3 S(O) 2 , with NO 2

The mechanism of the reaction between the methylsulfonyl radical, CH 3 S(O) 2 , and NO 2 is examined using density functional theory and ab initio calculations. Two stable association intermediates, CH 3 SNO 2 and CH 3 S(O)ONO, may be formed through the attack of the nitrogen or the oxygen atom of NO 2 radical to the S atom. Interisomerization and decomposition of these intermediates are investigated using high level energy methods and specifically, CCSD(T), CBS‐QB3, and G3//B3LYP. The computational investigation indicates that the lowest energy reaction pathway leads to the products CH 3 S(O) 3 + NO, through the decomposition of the most stable association adduct CH 3 S(O)ONO. This result fully supports the relevant assumption of Ray et al. (Ray et al., J. Phys. Chem. 1996, 100, 8895], on which the experimental evaluation of the rate constant was based, namely that CH 3 S(O) 3 + NO are the most probable products of the reaction CH 3 S(O) 2 + NO 2 . © 2014 Wiley Periodicals, Inc.