Orientation dependence of the CN *(B, A) formation in the reaction of Ar( 3P) with the oriented CH 3CN

Abstract

The CN *(B, A-X) chemiluminescence as a function of the collisional geometry from the “head” to the “tail” orientation was studied in the reaction of the Ar( 3P) atoms with the oriented CH 3CN molecules using hexapole state selection. A large orientation dependence of CN emission was observed. The intensities of the CN emission were analyzed by the hard-sphere model, and it was found that the ratio of the emission probabilities for the head-on and the tail-end attacks was ≈ 3.1. This large stereo anisotropy in CN * formation is discussed in terms of the overlap between the molecular orbitals of CH 3CN and the atomic orbital of Ar( 3P).