Molecular beam chemistry: Reactions of Cs+ with benzyl chloride

Abstract

Angular and translational energy distributions for the C7H7+ and C5H+5 products from the reactions of Cs+ with benzyl chloride are reported. The kinematic contour diagrams for the C7H7+ at collision energies of 7.5 eV and 9.5 eV show that there are two direct mechanisms operative: a strippinglike process that is the more important at the lower energy and a repulsive, backward-scattering process that seems to involve electronic excitation of the benzyl chloride and that dominates at the higher energy. The C5H5+ product is found to be scattered nearly isotropically at 9.5 eV, but essentially entirely backward at 14.4 eV. This is shown to be consistent with the mechanism that requires electronic excitation of the benzyl chloride, followed by the decomposition of an excited benzyl ion. A ’’propensity rule’’ is also observed in that of all the possible energetically allowed products of the reaction, only those with a singlet ground state are found.