Structures, energies and harmonic vibrational frequencies for the reactions of NH with NO and NO2

The optimised geometries for reactants, intermediates, transition states and possible products for the reaction of NH with NO obtained at the HF/6-31G*, MP2/6-31G* and HF/6-311G** levels of theory and for the reaction of NH with NO2, obtained at the HF/6-31G* and HF/6-311G** levels of theory, are given. HF//HF, MP2//MP2, MP4SDQ//HF and MP4SDQ//MP2 energies are given. Harmonic vibrational frequencies are reported for all species. The calculations suggest that the major product of the reaction of NH + NO should be N2+ OH, as observed experimentally, rather than N2O + H owing to the stability of the HNNO complex. The channel leading to N2O + OH from NH + NO2 should have a positive temperature dependence in contrast to the observed overall negative temperature dependence.