Kinetics of CN radical reactions with NO_x between 297 and 740 K

The kinetics of the reaction of CN radicals with NO and NO₂ have been studied with the two-laser pump-probe technique at temperatures between 297 and 740 K over a broad range of pressure. The CN + NO reaction was found to be strongly pressure dependent and the rate constant measured at 100 Torr of Ar has a negative temperature coefficient of 10.4 kJ/mol. These results suggest that the reaction occurs mainly be recombination and there is no evidence of CO + N₂ formation up to 740 K. The CN + NO₂ reaction was found to be very fast and pressure independent and the measured bimolecular rate constant can be represented by k₂ = 10^-10.40±0.12 exp + [(186 ± 23)/T] cm³/molecule s.