Dynamics of vibrationally excited ozone formed by three-body recombination. I. Spectroscopy

Abstract

Spectrally resolved infrared fluorescence near 10 μm from vibrationally excited O₃(ν₃) has been observed in a cryogenic reactor facility at low pressure. The excited O₃(v) is formed principally by three‐body recombination of O and O₂ in flowing, microwave‐discharged O₂/Ar mixtures at 1 Torr and 80 K. The spectral resolution is sufficient to permit identification and assignment of band centers for up to five quanta of stretching excitation. The observed transition frequencies are consistent with those predicted from a Darling–Dennison perturbation treatment. The spectra, which sample the recombination/deactivation sequence in its early to middle stages, indicate surprisingly little intermode coupling, being predominantly ν₃ in character. There is also evidence of O₃(v) excitation by near‐resonant V–V coupling between O₃ and O₂(v=2). The spectroscopic analysis of the data is described, and considerations for scaling the spontaneous transition probabilities with vibrational level are discussed.