Inelastic state-to-state scattering of OH (2Π3/2,J=3/2,f) by HCl.

Parity resolved state-to-state cross sections for inelastic scattering of OH (X ²Π) by HCl were measured in a crossed molecular beam experiment at the collision energy of 920 cm^-1. The OH (X ²Π) radicals were prepared in a single quantum state, Ω=3/2, J=3/2, M_J=3/2, f, by means of electrostatic state selection in a hexapole field. The rotational distribution of the scattered OH radicals by HCl was probed by saturated LIF spectroscopy of the 0-0 band of the A ²Σ⁺–X ²Π transition. Relative state-to-state cross sections were measured for rotational excitations up to J=9/2 within the Ω=3/2 spin–orbit manifold and up to J=7/2 within the Ω=1/2 spin–orbit manifold. A propensity for spin–orbit conserving transitions was found, but no propensity for excitation into a particular Λ-doublet component of the same rotational state was evident. The data are presented and discussed in comparison with results previously obtained for collisions of OH with CO (E_coll=450 cm^-1) and N₂ (E_coll=410 cm^-1) and with new data we have measured for the OH+CO system at a comparable collision energy (E_coll=985 cm^-1). This comparison suggests that the potential energy surface (PES) governing the interaction between OH and HCl is more anisotropic than the PES’s governing the intermolecular interaction of OH with CO and N₂. [ABSTRACT FROM AUTHOR]