Vibrational energy dependence of the reactionN2+(v) +H2 →N2H+ +H at thermal energies

The hydrogen atom transfer reaction between N2+ and H2 has been studied at thermal energies as a function of the initial vibrational excitation of the N2+ molecular ion. The rate constant is approximately the same forv = 0 to v = 3 and is slightly smaller forv = 4. The absolute values exceed the Langevin rate, in good agreement with previous studies. The observations can be explained by a model in which the first step in the formation of N2H+ consists of a charge transfer at large intermolecular distances. Finally, it is shown that vibrational deactivation is of minor importance in theN2+(v) +H2 system.