Infrared chemiluminescence studies using a SISAM spectrometer. Reactions producing vibrationally excited OH

Abstract

A SISAM (spectromètre interférential à sélection par l'amplitude de modulation) has been utilised for the first time to observe the infrared chemiluminescence emitted by vibrationally excited OH produced by the reactions H + O₃→ OH + O₂(1) and H + NO₂→ OH + NO (2) under ‘arrested relaxation’ conditions. The experiments yield the following relative vibrational populations: for reaction (1), N₉: N₈: N₇: N₆= 1.0:0.55 ± 0.05:0.35 ± 0.05:0.17 ± 0.08; for reaction (2), N₁: N₂: N₃= 1.0:0.31 ± 0.06:0.07 ± 0.02. The results are compared with those from previous studies using different techniques, and the dynamics of the reactions are discussed briefly.