Kinetic studies of the gas phase INO2 self-reaction

Abstract

Flash photolysis of CF₃I/NO₂/N₂ gas mixtures has demonstrated the presence of the INO₂ self-reaction: INO₂ + INO₂ → I₂ + 2NO₂The occurrence of reaction (1) has been confirmed through simultaneous monitoring of NO₂ and I₂ by time-resolved UV-visible absorption spectroscopy. The second order rate coefficient for reaction (1), k₁, has been measured and the first temperature dependence study of k₁ has been carried out. A positive temperature dependence for k₁ was observed between 277.7 and 344.8 K which is described by k₁(T) = (4.7 ± 0.55) × 10⁻¹³ exp((−1670 ± 340)/T) molecule⁻¹ cm³ s⁻¹. Errors are 2σ. The atmospheric implications of these results are briefly discussed.