Trajectory study of the reaction O(1D2)+HCl→OH+Cl on a fitted ab initio surface

We performed a classical trajector study of the reaction O(1D)+HCl→Cl+OH using an analytical potential energy surface fitted to extensive ab initio calculations. The reactions proceed via long-living HOCl complexes before breaking up into products. Because no barrier is present for insertion pathways the total cross section is a decreasing function of the energy. The vibrational OH distribution is inverted and peaks at ν′=2–3. The ratio P(ν′=1)/P (ν′=0) is 1.42 and agrees very well with the experimental value of 1.5. The rotational OH distribution within the vibrational ground state is highly inverted, peaks at about j′=28, and is in good agreement with recent experimental data. The angular OH distribution is slightly forward peaked. The results for O(1D)+HCl→Cl+OH are compared with those for the similar reaction O(1D)+H2→H+OH.