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

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.