Theoretical Rate Coefficients for the Reaction of Methyl Radical and Hydroperoxyl Radical and for Methylhydroperoxide Decomposition

The kinetics of the CH3 + HO2 bimolecular reaction and the thermal decomposition of CH3OOH are studied theoretically. Direct variable reaction coordinate transition state theory (VRC-TST) is used to compute the high pressure limit rate coefficient for the CH3 + HO2 reaction and to characterize the transition state region of the barrierless CH3O + OH product channel. The CH2O + H2O product channel is treated using variational transition state theory and the harmonic oscillator and rigid rotor approximations. Pressure dependence and product branching are modeled using master equation simulations. The predicted rate coefficients for the major products channels of the bimolecular reaction, CH3O + OH and CH4 + O2, are found to be in excellent agreement with values obtained in two recent modeling studies.