Pressure and temperature dependence of the rate of reaction between CN radicals and NO over the range 99 ⩽T/K ⩽ 450

Abstract

Pulsed laser photolysis, laser-induced fluorescence experiments have been performed on the kinetics of reaction between CN radicals and NO. The measurements cover a range of temperature (99 ⩽T/K ⩽ 450) and total pressure {at 296 K, 5–400 Torr [1 Torr =(101 325/760) Pa]; at other temperatures, a smaller range}. Two methods were employed to extract rate constants in the limit of low and high pressure and their temperature dependences from the experimental results. Comparison of the values of the low-pressure rate constants derived from experiment with calculated values suggests that levels derived, in zeroth order, from the excited S₁ and T₁ electronic states mix with those in the ground S₀ state thereby contributing to the density of NCNO states in the region of the CN + NO dissociation limit and hence to the rate of association in the limit of low pressure.