Rate constants for the reactions of O2+(a 4Πu) ions with N2, Ar, CO, CO2,H2, and O2 at relative kinetic energies 0.04–2 eV

Abstract

Rate constants for the reaction of O⁺₂(a ⁴Π_u) metastable ions with N₂, Ar, CO, CO₂, H₂, and O₂, which do not react with O⁺₂(X ²Π_g, v=0) ground‐state ions, have been measured for the relative kinetic energies 0.04–2 eV in a flow‐drift tube. With the exception of O₂ and CO, most of the rate constants are near the respective Langevin limits. The rate constant for the reaction with CO exhibits a pronounced minimum at 0.3 eV; the other reactions show much less variation with energy. Up to 2 eV, quenching of the a ⁴Π_u metastable state to the X ²Π_g ground state of O⁺₂ appears to be small compared to the reactive losses of O⁺₂(a ⁴Π_u) ions. The reactive process is charge transfer, except for CO and H₂. For CO, CO⁺ and CO⁺₂ are formed roughly in the ratio 5:1 and for H₂, only O₂H⁺ is formed.