Energy dependence, kinetic isotope effects, and thermochemistry of the nearly thermoneutral reactions N+(3P)+H2(HD,D2)→NH+(ND+)+H(D)

The reactions of N+(3P) ions with H2, HD, D2 are examined using guided ion beam tandem mass spectroscopy. Absolute reaction cross sections are measured from near thermal energies to 30 eV relative energy. The low energy cross section behavior is analyzed using empirical threshold models and phase space theory. The results are compared to other recent studies of the N++H2 system. The reaction endothermicity for N+(3P)+H2→NH++H, ΔH○0 =0.033±0.024 eV (0.76±0.55 kcal/mol), and the bond energy of NH+, D○0(N–H+) =3.51±0.03 eV (80.9±0.6 kcal/mol), are derived from the results.