Dissociation rate calculations based on photodissociation ion kinetic energy spectra

Abstract

The quasi-equilibrium theory (QET) in applied to the calculation of photodissociation daughter-ion currents. Treatments are given for a single reaction pathway from the molecular ion, and also for two competing reaction pathways. With particular reference to the photodissociation spectrum of the nitrobenzene molecular ion, which undergoes two competing reactions, it is found that good agreement can be achieved between calculated and observed ion kinetic energy spectra by treating as adjustable parameters only the frequency factor for NO − loss and the number of effective oscillators. It is shown that other factors which could influence the calculated results, such as the exact form of the internal energy distribution, are unimportant to first order. The fitting of calculated to experimental results leads to unique values for the frequency factor and the number of oscillators.