Quenching rates for CO +2 emission excited by 58.4nm irradiation of CO2

Abstract

Rate constants have been determined for quenching of emission from the (0,0,0) level of CO⁺₂(B²Σ⁺_u) and the (3,0,0) level of CO⁺₂(A²Π_u) by CO₂, H₂, N₂, O₂, CO, N₂O, C₂H₆, Ar, Ne and He. For most of the reactants the quenching rates exceed 2 × 10^–9 cm³ molecule^–1 s^–1, with smaller values observed for He and Ne. The measured rates represent reaction cross-sections 1–40 times greater than gas-kinetic values. Such efficient quenching is explained in terms of a charge-transfer mechanism which results in rapid conversion of electronic energy into translation.