Product formation in the association reaction of ClO with NO 2 investigated by diode laser kinetic spectroscopy

Diode laser spectroscopy has been employed to monitor the formation of chlorine nitrate (ClONO 2 ) in the association reaction of ClO with NO 2 . Chlorine nitrate is the only stable end‐product of this reaction at room temperature. Time‐resolved measurements of ClONO 2 formation using molecular modulation showed no evidence for any involvement of unstable isomers of ClNO 3 in the reaction. These measurements gave a value of k 1 = (1.8 ± 0.4) × 10 −31 cm 6 /molecule 2 · 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.