ANGULAR-DISTRIBUTIONS OF REACTIVE SCATTERING ARISING FROM PERSISTENT COMPLEXES WITH DISSOCIATION AT ARBITRARY ANGLES TO THE INERTIAL AXES OF THE TRANSITION-STATE

Angular distributions of reactive scattering arising from a long-lived collision complex dissociating via a transition state that approximates to a linear rotator are predicted for H atom displacement occurring over a distribution of bending angles beta with respect to the rotator axis. A conical angular distribution may be generated when only a narrow range of bending angles contributes to the reactive scattering. However, the angular distribution may take on quite different character as the distribution of bending angles becomes broader. Thus, an isotropic angular distribution is generated by a bending angle distribution which follows the spherical polar weighting P(beta) alpha sin beta. Forward and backward scattering is generated by bending angle distributions favouring less strongly bent displacement, while sideways scattering is generated by a bending angle distribution favouring more strongly bent displacement. The experimental angular distribution for OH + CO reactive scattering which shows mild forward and backward peaking, corresponds to a range of bending angles for H atom displacement from the H-OCO transition state which is broadened about the nominal preferred direction beta = 45 degrees but avoids strongly bent directions with beta approximate to 90 degrees.