Dynamics of the CH3 + OH Reaction

作者：Ree J; Kim Y H; Shin H K^*

来源：International Journal of Chemical Kinetics, 2011, 43(9): 455-466.

DOI：10.1002/kin.20568

We study dynamics of the CH3 + OH reaction over the temperature range of 300-2500 K using a quasiclassical method for the potential energy composed of explicit forms of short-range and long-range interactions. The explicit potential energy used in the study gives minimum energy paths on potential energy surfaces showing barrier heights, channel energies, and van der Waals well, which are consistent with ab initio calculations. Approximately, 20% of CH3 + OH collisions undergo OH dissociation in a direct-mode mechanism on a subpicosecond scale (<50 fs) with the rate coefficient as high as similar to 10(-10) cm(3) molecule(-1) s(-1). Less than 10% leads to the formation of excited intermediates CH3OH dagger with excess vibrational energies in CO and OH bonds. CH3OH dagger stabilizes to CH3OH, redissociates back to reactants, or forms one of various products after intramolecular energy redistribution via bond dissociation and formation on the time scale of 50-200 fs. The principal product is (CH2)-C-1 (kCH(2) being similar to 10(-11)), whereas ks for CH2OH, CH2O, and CH3O are similar to 10(-12). The minor products are HCOH and CH4 (k similar to 10(-13)). The total rate coefficient for CH3 + OH -> CH3OH dagger -> products is similar to 10(-11) and is weakly dependent on temperature.

• 出版日期2011-9