KINETIC ANALYSIS OF ION-MOLECULE REACTIONS IN NITROGEN-HYDROGEN MIXTURES USING ION CYCLOTRON RESONANCE

The thermal energy rate constants for the reactions N2 ++D2→k1N2D++D, N2++H2→k2N2H ++H, N2++HD→k4aN 2H++D →k4bN2D++H, have been measured using ion cyclotron resonance (icr) giving ki= 1.15, k3=1.41, k4a=0.65, and k4b=0.69× 10-9 cm3 molecule-1·sec-1. These results agree very well with the values calculated from the change-induced dipole model of Gioumousis and Stevenson. The absence of a significant isotope effect in k4a. and k4b, indicates these reactions proceed via a stripping mechanism as indicated by Wolfgang and co-workers and Mahan and co-workers. Energy dependence studies of k2 and the corresponding charge exchange rate constant D2++N2→ k2N2D++D D2++N 2→k5D2+N2+ indicate that the decrease in fe with increasing reactant ion energy is approximately offset by the increase in h as predicted by the phase-space theory of Light.