Donor-Acceptor Interactions Relevant to Charge Separation and Charge Transport

Electronic interactions in Donor-Acceptor and Donor-Bridge-Acceptor systems have garnered increased interest in the last decade due to the importance of electronic coupling (Hab) in molecular electronics. Our efforts have focused on determining excited state contributions to bridge mediated electronic coupling, understanding how open-shell excited state singlet configurations promote long-range electron correlation, and developing new platforms for spin control of excited state dynamics in photoexcited donor-acceptor molecules. Using novel Donor-Bridge-Acceptor biradical complexes, we have been able to test recent theoretical hypotheses in molecular electronics as they relate to coherent superexchange in electron transfer/transport conduits, spin-polarized electron transport, and the control of quantum interference effects. Radical elaborated transition metal complexes represent ideal platforms for exploring the relationship between photoinduced charge separation and long-range spin correlation, impacting the photomagnetic molecular device and molecular spintronics fields. Here we will show how a combined spectroscopic approach augmented by detailed bonding calculations has provided keen insight into the electronic structure of novel transition metal ¿ radical complexes, furthering our understanding of electron and spin transport, long-range electron correlation, and excited state dynamics in molecular electronic systems at the nanoscale. (Host: Prof. Michael Therien)