TIME-RESOLVED FTIR EMISSION STUDY OF PRODUCT DYNAMICS IN THE NO+NCO REACTION

Product IR chemiluminescence in the NO + NCO reaction has been recorde d using time-resolved FTIR spectroscopy. Emission was observed from hi ghly vibrationally excited CO2 and N2O, produced from two competing ch annels and emitting in the Delta v(3) = -1 transitions between 2000-24 00 cm(-1). The spectra are consistent with both molecules having total vibrational energies which are approximately equal to those predicted from prior distributions, but the partitioning between the individual vibrational modes is markedly non-statistical. In particular, CO2 exh ibits much less excitation in nu(3) (estimated as 0.6 +/- 0.2 quanta p er molecule) than statistically predicted. Emission from the (0, 0, 1) levels of both CO2 and N2O was measured, and their relative intensiti es and kinetic behaviour shown to be consistent with a model of relaxa tion of the nascent vibrational distributions in which product-channel branching ratios were taken to be equal to those previously determine d from end-product analyses.