Scattering of Potassium by a Series of Reactive and Nonreactive Compounds in Crossed Molecular Beams

Abstract

The scattering of potassium by the nonreactive compounds C(CH₃)₄, C₆H₆, C₆H₁₂, (CH₃)₂C=C(CH₃)₂ and the reactive compounds CH₃I, CCl₄, SiCl₄, SnCl₄, SF₆ has been studied in experiments with crossed molecular beams. In each case the nonreactive scattering of velocity‐selected K was measured as a function of laboratory scattering angle at a number of initial relative kinetic energies. Except for K+SnCl₄, rainbow scattering is observed. The differences which appear between the measured scattering in this region for the various nonreactive compounds show the influence of the molecular structure on the intermolecular potential. Potential parameters of an assumed spherically symmetric potential (exp−6, α=12) are calculated from the rainbow scattering. The scattering of K from the various reactive compounds differs markedly at larger angles and is an indication of a correspondingly large variation of reaction cross sections. Probabilities of reaction, threshold energies, threshold distances, and the energy dependence of the total reaction cross sections are obtained from an interpretation of the measurements.