THERMAL KINETICS IN SMALL SYSTEMS .2. GENERALIZED ARRHENIUS PLOTS WITH APPLICATIONS TO THE DISSOCIATION OF BENZENE AND SUBSTITUTED-BENZENE CATIONS

Rate constants for the dissociation of isolated benzene and substituted-benzene cations are analyzed. In the first section Arrhenius activation energies are deduced. A primitive version of the adiabatic channel model is then used to reduce these activation energies to their values at zero Kelvin. A value for the heat of formation at that temperature of the C 6H5+ ion equal to 1130 kJ/mol is reported. Attention is drawn to a remarkable constancy (and also two anomalies) in the frequency factors for these reactions. The predictive capability of the adiabatic channel model is then examined. It is found to yield kinetic isotope effects in good agreement with experiment. © 1990 American Institute of Physics.