Quantum Mechanics in Biology: Photoexcitations in DNA

Abstract

We consider here the theoretical and quantum chemical descriptionof the photoexcitated states in {DNA} duplexes. We discuss the motivationand limitations of an exciton model and use this as the startingpoint for more detailed excited state quantum chemical evaluations.In particular, we focus upon the role of interbase proton transferbetween {Watson/Crick} pairs in localizing an excitation and thenquenching it through intersystem crossing and charge transfer.