Low Temperature NH(X 3Σ-) Radical Reactions with NO, Saturated, and Unsaturated Hydrocarbons Studied in a Pulsed Supersonic Laval Nozzle Flow Reactor between 53 and 188 K

The reactions of ground-state imidogen radicals (NH(X 3Σ-)) with NO and select saturated and unsaturated hydrocarbons have been measured in a pulsed supersonic expansion Laval nozzle flow reactor in the temperature range 53−188 K. The rate coefficients for the NH + NO system display negative temperature dependence in the temperature regime currently investigated and a global temperature-dependent fit is best represented in a modified power law functional form, with k1(NH + NO) = (4.11 ± 0.31) × 10-11 × (T/300)(-0.30±0.17) × exp(77±21/T) cm3/s. The reactions of NH with ethylene, acetylene, propene, and diacetylene were measured over the temperature range 53−135 K. In addition, the reactions of NH with methane and ethane were also measured at 53 K, for reasons discussed later. The temperature dependence of the reactions of NH with the unsaturated hydrocarbons are fit using power law expressions, k(T) = A(T/300)-n, and are as follows:  k4 = (2.3 ± 1.2) × 10-12 × (T/300)(-1.09±0.33) cm3/s, k5 = (4.5 ± 0.3) × ...