Imaging the Reaction Dynamics of O(3P)+CH4→OH+CH3

The title reaction was studied in a crossed-beam experiment, in which the ground-state methyl products were probed using a time-sliced velocity-imaging technique. By taking images over the energy range of chemical significance, from the threshold to about 15 kcal mol(-1), the reactive excitation function as well as the dependences of product angular distributions and of the energy disposal on initial collision energies were determined. All experimental data are consistent with the picture that the ground-state reaction of O(P-3)+CH4 proceeds via a direct abstraction rebound-type mechanism with a narrow cone of acceptance. Deeper insights into the underlying mechanism and the key feature of the potential-energy surface are elucidated by comparing the results with the corresponding observables in the analogous Cl+CH4 reaction.