Effect of Rotational Excitation on Stereodynamics for the Reactive Collision Between N(2D) and H2

Abstract

Effect of rotational excitation on stereodynamics for the N(2D)+H2(v = 0, j = 0–5)→NH(v′, j′)+H collision reactions is investigated by employing the quasiclassical trajectory method. Based on an accurate 12A″ potential energy surface, three angular distributions P(θr), P(ϕr), P(θr, ϕr), and polarized-dependent differential cross section are calculated at a collision energy of 5.1 kcal/mol. It is found that the P(θr) distribution has a distinct peak at about θr = 90°. The P(ϕr) distribution has a small peak at about ϕr = 270° and no peak at about ϕr = 90°. This implies that the product angular momentum j′ is not only aligned perpendicular to k, but also orientated to the negative direction of the y axis. The product rotational alignment and orientation become increasingly weaker with an increase of the rotational quantum number j of H2. Analysis of trajectory propagation demonstrates that the title collision reaction has a dominant indirect insertion mechanism and a minor direct H-abstraction mechanism.