Dynamics of the reaction O(P-3)+H2S -> OH+SH. 1. Rotational, Lambda doublet, and fine structure distributions in the OH(upsilon ''=1) product

Rotational, spin-orbit, and A doubler populations have been measured in the OH(upsilon " = 1) product of the O(P-3) + H2S reaction. Ground-state O ato ms with kinetic energies above the barrier to reaction were formed by photo lysis of NO2 at 355 nm. Rotational populations were found to be hotter than statistically predicted, with excitation up to the energetic limit in a di stribution that suggests efficient conversion of reagent kinetic energy int o OH product rotation. Spin-orbit ratios show approximately equal populatio ns in the (2)Pi(3/2) and (2)Pi(1/2) states of OH, but Lambda doublers favor the symmetric A' level for all measured values of N ". A model of the dyna mics involving a planar transition state is invoked to explain the observat ions and predicts the SH cofragment to be formed in the A " Lambda doubler with little rotational energy.