Journal of Chemical Physics, Vol.106, No.22, 9182-9189, 1997
Rotational and Spin-Orbit Effects in the Dynamics of O(P-3(J))+hydrocarbon Reactions .2. Models for Spin-Orbit Propensities
The spin-orbit states of OH have been found in part I to be unequally populated in reactions of O(P-3(j)) with saturated hydrocarbons. We clarify the correlations in these systems within an adiabatic, Omega-conserving approximation, and show that the observed OH spin-orbit distributions are not well reproduced in this adiabatic limit. However, the inclusion of strong nonadiabatic coupling between surfaces of the same Omega and parity results in a much improved prediction. The necessary mixing is demonstrated to be compatible with a previous independent characterization of the entrance channel surfaces in O(P-3(j)) + CH4 collisions, and with the known propensities for inelastic, j-changing collisions of O(P-3(j)) with closed shell partners. The nonadiabatic model which agrees best with the observed OH spin-orbit ratios suggests that the O(P-3(j)) reactivity should vary only moderately with j.
Keywords:QUANTUM-MECHANICAL TREATMENT;FINE-STRUCTURE TRANSITIONS;STATE ATOM COLLISIONS;SATURATED-HYDROCARBONS;CHEMICAL-DYNAMICS;ANGULAR-MOMENTUM;MOLECULAR-BEAM;ENERGY;O(P-3);EXCITATION