Abstract

One of the most attractive systems in molecular dynamics and spectroscopy involves molecules containing two chromophores, in which there are two degenerate diabatic electronic states. Photodissociative systems are especially interesting due to the presence of competition between the fast electronic surface hopping and nuclear dissociative motion. The dissociation serves as a built-in clock for "timing" the rate at which the electronic excitation hops. We represent such a two chromophore system as A₁-B-A₂ with A₁ equivalent to A₂. If there is no coupling between A₁-B and B-A₂ it recovers the simple single chromophore system. When there is coupling between A₁-B and B-A₂, the two chromophores can "communicate" on an extremely rapid time scale, which complicates the dissociation dynamics. The dynamics of such a system are governed by the rate with which the electronic excitation hops from A₁ to A₂ or A₂ to A₁. How fast the electronic hopping happens depends on the coupling strength between the two chromophores. To develop a general technique to probe the dissociation dynamics and the electronic surface hopping is the purpose of the present paper.

© 1990 Optical Society of America