Polarization effects in reactive scattering of Na atoms in the 4D level

Experiments performed using a crossed beam apparatus have shown that the reactivity of Na(4D) with HCl and O₂ changes substantially as the 4d orbital alignment is varied. This change is found to be different for the two reactions. The favorable alignment for the reaction with HCl has thed orbital aligned along the relative velocity vector of the reactants. This result is consistent with a long range electron transfer initiating the reaction and suggests that the Na-Cl axis dominates over the H-Cl axis in determining the favorable atomic orbital alignment. For the reaction with O₂, the NaO formation has a high translational energy threshold, and the favored orbital alignment varies as a function of the NaO laboratory scattering angle. Very restricted conditions are found to be necessary for the reaction: near collinear geometry and thed orbital perpendicular to the molecular axis.