Reactive scattering of Na(3 2P3/2)+HCl

Abstract

The reaction of electronically excited Na(3P) atoms with HCl has been studied in a crossed molecular beams experiment. At collision energies slightly above the endoergicity of the reaction, Na(3P) shows a dramatic enhancement of reactivity over ground state Na(3S). Detailed measurements of the laboratory angular and velocity distributions of the reactively scattered NaCl product at 5.4 kcal/mol collision energy have allowed determination of the product center-of-mass translational and angular distributions. These experimental results are compared to the DIPR model of electron transfer reactions. The broad translational energy distribution is in qualitative agreement with the DIPR model, but the angular distribution exhibits reduced intensity for scattering perpendicular to the relative velocity vector which cannot be reproduced by the DIPR model. The preferred transition state configuration, Na–Cl–H, is consistent with what would be predicted by a diffuse 3P orbital where the Na atom appears ion-like. This configuration is opposite to that given by the dominant term in the long range multipolar expansion of the neutral reactant potential.