Inelastic F–H2 scattering

Abstract

We present a first experimental study of inelastic, rotational excitation cross-sections in a reactive collision. By preliminary model calculations we show that these measurements provide an ideal method for probing the anisotropy in the rate-determining entrance-channel valley of the potential-energy surface for the F–H₂ reaction. A comparison with the non-reactive Ne–D₂, H₂ scattring system reveals the importance of a surprisingly large fourth-order Legendre term in the anisotropic expansion of the F–H₂ potential. This particular shape feature is related to the incipient chemical reaction and is absent in the more ellipsoidal shape of non-reactive potentials for rare gas–H₂ systems.