The multichannel reaction NH2 + NH2 at ambient temperature and low pressures

NH2 profiles were measured in a discharge flow reactor at ambient temperature by monitoring reactants and products with an electron impact mass spectrometer. At the low pressures used (0.7 and 1.0 mbar) the gas-phase self-reaction is dominated by a ‘bimolecular’ H2-eliminating exit channel with a rate coefficient of k3b(300 K) = (1.3 ± 0.5) × 10−12 cm3 molecule−1 s−1 and leading to N2H2 + H2 or NNH2 + H2. Although the wall loss for NH2 radicals is relatively small (kw ≈ 6–14 s−1), the contribution to the overall NH2 decay is important due to the relatively slow gas-phase reaction. The heterogeneous reaction yields N2H4 molecules.