A shock tube study of the reactions of NH with NO, O2, and O

The reactions of NH(X3Σ−) with NO, O2, and O have been studied in reflected and incident shock wave experiments. The source of NH in all the experiments was the thermal dissociation of isocyanic acid, HNCO. Time-histories of the NH(X3Σ) and OH(X2Π) radicals were measured behind the shock waves using cw, narrow-linewidth laser absorption at 336 nm and 307 nm, respectively. The second-order rate coefficients of the reactions: were determined to be: and cm3 mol−1 s−1, where ƒ and F define the lower and upper uncertainty limits, respectively. The branching fraction of channel defined as k3b/k3total, was determined to be 0.19 ± 0.10 over the temperature range of 2940 K to 3040 K.