Computations and Estimates of Rate Coefficients for Hydrocarbon Reactions of Interest to the Atmospheres of the Outer Solar System

ION REACTIONS The technique for estimation of activation energies for simple atom transfer reactions was developed by Johnston and coworkers (1963, 1966). The method is based upon the concept of conservation of bond order during the reaction process. Here bond order is defined as a number which is related to the strength of the chemical bond, hence bond energy-bond order (BEBO). In this notation the carbon-carbon bond is of order 3 in acetylene, order 2 in ethylene, and order 1 in ethane. It is assumed, in the BEBO methodology, that as one bond is broken during a chemical reaction another is formed and that the sum of the bond orders for the two bonds, the formed and broken bond, remains constant. Empirical relationships between bond lengths, dissociation energies, and vibrational frequencies have been developed and used in the BEBO formulation to describe