Transition-state theory treatment of capture collisions between ions and symmetric top dipolar molecules

Abstract

Classical microcanonical transition-state theory gives the reduced rate coefficient for the capture of an ion by a symmetric top dipole which is dependent on two dimensionless parameters: ξ, which is defined by molecular constants of the system exclusively and X₁ which is additionally defined by energy. Examination of the energy dependence of the microcanonical rate coefficient reveals that at both ξ→ 0 and ξ→∞ the values obtained are larger by ca. 20% than those estimated for the ion–linear dipole capture. However, thermal averaging results in complete removal of this difference. Apparently, the dipole symmetry is of little consequence under the condition of thermal equilibrium.