Ultraviolet emission in O+–H2 reactive scattering

Abstract

Luminescence resulting from O⁺–H₂ collisions at relative energies between 1.5 and 35 eV has been studied in order to identify internal energy states of product species; A→X transitions of OH and OH⁺ are observed. Metastable states of reactant O⁺ are shown to be responsible for the production of these excited species at low relative energies; ground state O⁺ ions may contribute to the OH⁺(A ³Π) yield when sufficient kinetic energy is available to surmount the energy barrier that probably exists in addition to the thermochemical endoergicity of the process. Ground state O⁺ does not appear to be a major factor in the formation of OH(A ²Σ⁺). These conclusions are consistent with the nature of the potential energy surfaces of H₂O⁺ inferred from an electronic state correlation diagram.