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

Effect of rotational excitation on stereodynamics for the N(2D)+H_(2)(v =0,j =0 - 5)→NH(v',j')+H collision reactions is investigated by employing the quasiclassical trajectory method.Based on an accurate 12 A″ potential energy surface,three angular distributions P(θr),P((φ)r),P(θr,(φ)r),and polarized-dependent differential cross section 2π/σ dσ00/dwt 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((φ)r) distribution has a small peak at about (φ)r =270° and no peak at about (φ)r =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 H_(2).Analysis of trajectory propagation demonstrates that the title collision reaction has a dominant indirect insertion mechanism and a minor direct H-abstraction mechanism.