Competitive charge–transfer and vibrational quenching of N+2 (X,v=1) in collisions with O2 and NO

Abstract

The competitive charge–transfer and vibrational quenching of N+2 (X,v=1) ions in collision with O2 and NO molecules have been found to have comparable rate constants. The vibrational relaxation rate constants are rationalized in terms of a vibrational predissociation mechanism occurring in relatively long-lived complexes (τ∼10−10−10−11 s). The large magnitudes are attributed to unusually large attractive ion–neutral interaction potentials resulting from a charge–transfer stabilization interaction resulting from the near resonance of the N+2 +NO→NO+(a 3Σ+)+N2 and N+2 +O2→O+2 (a 4Πu) +N2 interactions. The more favorable orbital overlap of the O+2(a 4πu) with N2 relative to that for O+2(X 2Πg) with N2 may explain the slight preference for vibrational quenching over charge transfer and also the order of magnitude faster O+2(a 4πu) charge–transfer with N2 compared to N+2 charge–transfer with O2.