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: equation image 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 equation image defined as k3b/k3total, was determined to be 0.19 ± 0.10 over the temperature range of 2940 K to 3040 K.