Dynamics of the O+-H2 reaction. I. Reactive scattering of O+(4S 3/2) at relative energies below 15 eV

Product velocity vector distributions show that the reaction O+(H2,H)OH+ and its isotopic variations proceed from ground state reactants to predominantly electronic ground state products via a direct interaction. Spectator stripping is a prominent feature at the lower relative energies of collision, but the stripping peak is lost at energies where the internal excitation of OH+ (3Σ−) makes it unstable to dissociation. Production of forward scattered electronically excited OH+, probably in the 1Δ state, is observable when the initial relative energy is high enough that OH+(3Σ−) formed by spectator stripping is unstable with respect to dissociation. At these relative energies, OH+ from HD is predominantly scattered into barycentric angles less than 90°, while the OD+ appears at approximately 90° at larger angles. The propensity for formation of OD+ at large angles can be understood in terms of general kinematic considerations which apply to collinear collisions.