Partition of the reverse activation energy in unimolecular decomposition of gaseous ions

Abstract

Model calculations, based on the simple proposition that the broad features of the partition of reverse activation energy in a unimolecular decomposition can be obtained by considering the composition of the reaction coordinate at the transition state, show good agreement with experiment for a number of ionic reactions. The theory predicts that conversion of this potential energy into translational energy of the products will tend to be favoured in endoergic reactions, while exoergicity is more likely to lead to the appearance of energy of the products' vibrations. Conversion of the potential energy into rotational energy of the products is largely determined by the conservation of angular momentum. We define a class of “unbalanced” reactions for which this conversion will be significant.