Association of N2 with NH+4 and H3O+(H2O) n , n =1,2,3

We used a plasma chromatograph-mass spectrometer to study association reactions in high purity nitrogen at atmospheric pressure between 27 and 200 °C. The thermodynamic data for the formation of N2⋅NO+, H2O⋅H3O+(H2O), and H2O⋅H3O+(H2O)2 are found to be in agreement with previous results obtained under very different conditions. The enthalpies and entropies of formation of the N2 clusters N2⋅NH+4 and (N2)nH3O+(H2O)p, were determined for (p=1, n=1–3), (p=2, n=1–3), (p=3, n=2). The values of −ΔH° and −ΔS° were estimated for (p=2, n=4) and (p=3, n=3). The binding energies are found to be low, except for N2⋅NH+4. The bond strength of the latter is certainly due to chemical bonding.