Electronically non-adiabatic transitions in the Evans–Polanyi valence bond model

Translational to electronic energy transfer with or without a concomitant chemical reaction is studied for the Evans–Polanyi model. We explore the possibility of light emission from an electronically excited state following a high-energy collision. This can be viewed as an inverse process to a Woodward–Hoffmann photochemically allowed four-center reaction. The collision is described using this Evans–Polanyi method where the two diabatic electronic states correlate with the states of the reactants and products. The effective coupling of the diabatic states is found to be localized and the non-adiabatic regime is transversed rapidly so that facile electronic excitation is possible.