Reactive scattering of a supersonic alkali atom beam K+I₂, IBr, CH₂I₂, CHI₃, CBr₄

Abstract

Angular distribution measurements of reactive scattering of a supersonic potassium atom beam by a series of halogen and halomethane molecules are reported with initial kinetic energies E ∼ 5–6 kcal mol^-1. Differential reaction cross sections for I₂, IBr, CH₂I₂ show decreased wide-angle scattering and decreased total reaction cross sections compared with thermal energies. The differential reaction cross section for CHI₃ is peaked in the forward direction (ϑ=0°) but that for CBr₄ peaks sideways at ϑ ∼ 40°. The variation in reaction dynamics is correlated with the potential energy curves of halomethane molecules and their anions as indicated by dissociative thermal electron attachment experiments.