Direct mapping of insertion reaction dynamics:: S(1D)+H2→SH+H

The Doppler-selected time-of-flight method was applied to map out the differential cross sections of the title reaction at two collision energies in a crossed-beam experiment. Roughly symmetric and highly forward-backward peaking angular distributions were observed at both energies. Vibrational structures of the SH product were resolved from the velocity measurements of the counter-product H-atom. Most of the angle-integrated observables can readily be understood on statistical grounds, which suggests that statistics plays the dominant role in determining the outcomes of this prototypical insertion reaction. In terms of more detailed angle-specific reaction attributes, significant discrepancies from statistical considerations were revealed, indicative of some hidden dynamics being buried under the statistical factor.