Distribution of vibrational populations of CO electronic states produced in CO2 photodissociation

Abstract

The vibrational distributions of CO(d ³Δ), CO(a′ ³Σ⁺), and CO(a ³Π) states produced from CO₂ photodissociation at various incident photon energies are calculated using a quantum mechanical theory of poyatomic molecule dissociation and are compared with experiment. It is assumed that CO(d ³Δ) and CO(a′ ³Σ⁺) are produced via direct photodissociation from the CO₂ ground state to a repulsive electronic state. Agreement between theoretical and experimental distribution is obtained. The CO(a ³Π) vibrational distribution calculated using the direct photodissociation assumption could not be made to agree with experiment. Evidence that the CO(a ³Π) dissociation in the photon energy range considered proceeds via a predissociative state of CO₂ is given. Comparisons are made with other models of dissociation.