KINETICS OF THE N+NCO REACTION AT 298 K

The rate constant for the reaction of NCO (X (2) Pi) radicals with N(S -4) atoms at room temperature has been determined to be (5.5 +/- 0.8) x 10(-11) cm(3) molecule(-1) s(-1) by direct measurement by laser-indu ced fluorescence. This result is 70% higher than a value estimated fro m shock tube data at 1700 K, and suggests that the reaction takes plac e over a largely attractive potential surface. When the result is comb ined with high temperature data, it suggests that the major products o f the reaction are N-2 + CO, but as these cannot be formed in their gr ound electronic states in a spin-allowed process, arguments are propos ed for the formation of triplet state products. No IR emission could b e assigned as originating from CO, and possible reasons for this are d iscussed.