A Quasiclassical Trajectory Study of the CH4+O(3P)→CH3+OH Reaction

The reaction of CH4+O(P-3)-> CH3+OH was studied with the quasiclassical trajectory calculation. Both CH4(v=0, j=0) and CH4(v=1, j=1) were used. The results showed that the reaction of CH4(v=0, j=0) + O(P-3)-> CH3+OH is a direct reaction at lower or larger impact parameters with the preferentially backward scattered OH, and the product OH is rotationally cold and in the vibrationally ground state, The reaction of CH4(v=1, j=1) + O(P-2)-> CH3 + is a peripheral dynamical reaction with the preferentially forward scattered OH. This reaction was found to proceed with two distinct mechanism: for trajectories with a large impact parameter, a very short lived complex is formed with a rotationally cold OH, which is in vibrationally excited state(v=1) and scattered into the forward direction; at smaller impact parameters, the reaction proceeds via a direct mechanism with a rotationally hot OH, which has little vibrational excitation and is scatted backward.