Ionic-state-resolved collision energy dependence of Penning ionization cross sections for OCS with He*-(23S) metastable atoms was measured in a wide collision energy range from 20 to 350 meV Anisotropic interaction potential for the OCS-He*(23S) system was obtained by comparison of the experimental data with classical trajectory simulations. It has been found that attractive potential wells around the O and S atoms are clearly different in their directions. Around the O atom, the collinear approach is preferred (the well depth is ca. 90 meV), while the perpendicular approach is favored around the S atom (the well depth is ca. 40 meV). On the basis of the optimized potential energy surface and theoretical simulations, stereo reactivity around the O and S atoms was also investigated. The results were discussed in terms of anisotropy of the potential energy surface and the electron density distribution of molecular orbitals to be ionized.
All Science Journal Classification (ASJC) codes