Exciplex Funnel Resonances in Chemical Reaction Dynamics

We report quantum mechanical calculations on a one-dimensional model of a chemical reaction with an electronically excited exciplex funnel over the saddle point to study the competition between direct reÑection from the upper diabat and metastable trapping (resonances). Particular emphasis is placed on the e†ect of the funnel on transition probabilities and delay times as a function of energy and as a function of the magnitude of the energy gap at the saddle point. Quantum dynamics calculations of energy-dependent transition probabilities for a series of energy gaps reveal a regime where the main e†ect is diabatic reÑectivity in direct, short-lived collisions and another regime where the main e†ect is a series of collisional resonances.