A Computational Study of the Kinetics and Mechanism for the C2H3 + CH3OH Reaction

The mechanism for the C₂H₃ + CH₃OH reaction has been investigated by the Gaussian‐4 (G4) method based on the geometric parameters of the stationary points optimized at the B3LYP/6–31G(2df, p) level of theory. Four transition states have been identified for the production of C₂H₄ + CH₃O (TSR/P1), C₂H₄ + CH₂OH (TSR/P2), C₂H₃OH + CH₃ (TSR/P3), and C₂H₃OCH₃ + H (TSR/P4) with the corresponding barriers 8.48, 9.25, 37.62, and 34.95 kcal/mol at the G4 level of theory, respectively. The rate constants and branching ratios for the two lower energy H‐abstraction reactions were calculated using canonical variational transition state theory with the Eckart tunneling correction at the temperature range 300–2500 K. The predicted rate constants have been compared with existing literature data, and the uncertainty has been discussed. The branching ratio calculation suggests that the channel producing CH₃O is dominant up to about 1070 K, above which the channel producing CH₂OH becomes very competitive.