Collinear quantum wave packet study of exothermic A + BC reactions involving an intermediate complex of linear geometry. Application to the C + NO reaction

Abstract

Using a quantum time-dependent wave packet approach, we have analysed the influence of the topology of the intermediate well on the collinear dynamics of the exothermic process A + BC → ABC → AB + C in which the masses are respectively 12, 14 and 16 u (1 u ≈ 1.66054 × 10^–27 kg). A large range of collisional energies has been investigated. Moreover, we have analysed the influence of the vibration of the reagents on the dynamics. Comparison with classical trajectory calculations has also been made. It results that an increase of the anisotropy of the well, defined as the ratio of the curvatures at the bottom of the well along AB and BC, favours the vibrational excitation of the newly formed bond AB. Since the reaction C + NO → CNO → CN + O corresponds to a weakly anisotropic CNO well, we predict that an inversion of population between the vibrational levels v′= 0 and v′= 1 of CN is expected to occur as long as the collisional energy increases.