Product formation in the association reaction of ClO with NO2 investigated by diode laser kinetic spectroscopy

Diode laser spectroscopy has been employed to monitor the formation of chlorine nitrate (ClONO2) in the association reaction of ClO with NO2. Chlorine nitrate is the only stable end‐product of this reaction at room temperature. Time‐resolved measurements of ClONO2 formation using molecular modulation showed no evidence for any involvement of unstable isomers of ClNO3 in the reaction. These measurements gave a value of k1 = (1.8 ± 0.4) × 10−31 cm6/molecule2 · s for the reaction \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm ClO}\,\, + \,\,{\rm NO}_{\rm 2} \,\, + \,\,{\rm M}\mathop {\longrightarrow} \limits^{k_1 } {\rm ClONO}_{\rm 2} \,\, + \,\,{\rm M} $$\end{document} at 295 K and an upper limit of 5 ms for the lifetime of any isomeric products at this temperature.