A DIODE-LASER STUDY OF THE NCO+NO2 REACTION

Infrared diode laser absorption spectroscopy was used to investigate t he kinetics and product channels of the NCO + NO2 reaction. The total rate constant was fit to the form k = 10(-11.38+/-0.06) exp[(441 +/- 5 3)/T] over the temperature range 298-500 K. The major product channel was CO2 + N2O, accounting for 91.7 +/- 4.0% of the total observed prod ucts; CO + 2NO accounted for the remaining 8.3 +/- 4.0%. The energy di sposal into the v(3) mode of the CO2 product was also measured. A valu e of (f(v3)) = 5.9 +/- 2.0% was determined. The results are consistent with formation of a long-lived O2NNCO collision complex with a roughl y statistical distribution of internal energy. Concerted dissociation via a four-center transition state leads to the primary products.