Vibrationally State-Selected Reactions of Ammonia Ions. 3. NH3(+)(v)+ND3 and ND3(+)(v)+NH3

摘要

The role of vibrational excitation of the umbrella bending mode of ND3 and ammonia ion on the reaction with NH3 and ND3 is examined over the 2 to 12 eV center of mass kinetic energy range. Isotopic substitution permits the investigation of charge transfer, proton/deuteron transfer, and neutral atom abstraction. The charge transfer channel is moderately enhanced by excitation of the ammonia ion v2 vibrational mode. The proton/deuteron channel is suppressed by vibrational excitation of the ion at low kinetic energies. The hydrogen/deuterium atom abstraction channels show nearly a factor of 6 vibrational enhancement relative to NH3 ion. The ion vibrational and translational energy play inequivalent roles in the reactions, indicating that nonstatistical factors are important in the transition from reactant to product channels. A simple dynamical model is offered to explain both the proton/deuteron transfer and the neutral atom abstraction reactions; it is based on the argument that vibrational motion along the particle transfer coordinate promotes reaction while vibrational motion perpendicular to the transfer coordinate hinders reaction.