TRANSITION-STATE THEORY TREATMENT OF CAPTURE COLLISIONS BETWEEN IONS AND SYMMETRICAL-TOP DIPOLAR MOLECULES

Classical microcanonical transition-state theory gives the reduced rat e coefficient for the capture of an ion by a symmetric top dipole whic h is dependent on two dimensionless parameters: xi, which is defined b y molecular constants of the system exclusively and X(1) which is addi tionally defined by energy. Examination of the energy dependence of th e microcanonical rate coefficient reveals that at both xi -->, 0 and x i -->, infinity the values obtained are larger by ca. 20% than those e stimated for the ion-linear dipole capture. However, thermal averaging results in complete removal of this difference. Apparently, the dipol e symmetry is of little consequence under the condition of thermal equ ilibrium.