Approaches to molecular devices based on controlled intramolecular electronic energy and electron transfer. Electron transfer rates through flexible molecular bridges by a time-dependent super exchange model

In this paper we propose to use intramolecular electron and electronic energy transfer as a way of connecting between logical operations that are implemented on different molecules. We have already shown that the rate of through-bond-mediated intramolecular singlet–singlet electronic energy transfer (EET) in certain rigid bichromophoric molecules is five orders of magnitude higher than that observed in flexibly linked systems containing the same donor– acceptor chromophores, for which through space EET via exchange interaction is dominant. This is the first direct evidence that the rigidity of the interchromophore bridge is significant for promoting through-bond bridge-mediated intramolecular EET. Preliminary results of a theoretical model for explaining this striking observation are discussed. 2003 Elsevier B.V. All rights reserved.