KINETICS AND PRODUCT CHANNELS OF THE REACTION CN+N2O

The kinetics of the reaction CN + N2O --> products have been measured between 400 and 870 K. Laser photolysis of ICN at 248 nm was used to p repare CN radicals, whose decay rate as a function of partial pressure of N2O was monitored by laser-induced fluorescence. The measured bimo lecular rate constants exhibit some dependence on total pressure and a re approximately a factor of 3 lower than obtained in the previous stu dy of Wang et al. [Int. J. Chem. Kinet. 1991, 23, 151], but have appro ximately the same temperature dependence. The results at 100 Torr are well represented by the expression 10(-10.0+/-0.4) exp(-7730+/-1300/T) +10(-14.5+/-0.4) exp(-730+/-730/T) over the temperature range 400-850 K. The branching ratio of the product channel CN+N2O --> NCO+N-2 was m easured at several temperatures by comparing the amount of NCO produce d between CN+N2O --> products and CN+O-2 --> NCO+O. The NCO channel is insignificant (<10% branching ratio) over the temperature range of th is study. Substantial NCN product formation is observed at 587 K, cons istent with NCN+NO being the primary product channel over this tempera ture range. Below 500 K the rate constant has a much weaker temperatur e dependence. These findings suggest that stabilization of the NCNNO a dduct may be significant at low temperatures.