title: Ultrafast Electronic Energy Transfer in an Orthogonal Molecular Dyad.
abstract: Understanding electronic energy transfer (EET) is an important ingredient in the development of artificial photosynthetic systems and photovoltaic technologies. Although EET is at the heart of these applications and crucially influences their light-harvesting efficiency, the nature of EET over short distances for covalently bound donor and acceptor units is often not well understood. Here we investigate EET in an orthogonal molecular dyad (BODT4), in which simple models fail to explain the very origin of EET. On the basis of nonadiabatic ab initio molecular dynamics calculations and ultrafast fluorescence experiments, we gain detailed microscopic insights into the ultrafast electrovibrational dynamics following photoexcitation. Our analysis offers molecular-level insights into these processes and reveals that it takes place on time scales ≲100 fs and occurs through an intermediate charge-transfer state.
authors.affiliation: Physics Department and Center for Optoelectronics and Photonics Paderborn (CeOPP), Universität Paderborn , Warburger Strasse 100, 33098 Paderborn, Germany.
authors.forename: Christian
authors.identifier: http://orcid.org/0000-0003-1286-0860
authors.initials: C
authors.lastname: Wiebeler
authors.affiliation: Institute for Theoretical Chemistry, Faculty of Chemistry, University of Vienna , Währingerstr. 17, 1090 Vienna, Austria.
authors.forename: Felix
authors.identifier: http://orcid.org/0000-0003-0751-148X
authors.initials: F
authors.lastname: Plasser
authors.affiliation: Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St. Andrews , North Haugh, St. Andrews, Fife KY16 9SS, United Kingdom.|Institut für Experimentelle und Angewandte Physik, Universität Regensburg , Universitätsstrasse 31, 93053 Regensburg, Germany.
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Hedley
authors.affiliation: Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St. Andrews , North Haugh, St. Andrews, Fife KY16 9SS, United Kingdom.
authors.forename: Arvydas
authors.initials: A
authors.lastname: Ruseckas
authors.affiliation: Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St. Andrews , North Haugh, St. Andrews, Fife KY16 9SS, United Kingdom.
authors.forename: Ifor D W
authors.identifier: http://orcid.org/0000-0001-7821-7208
authors.initials: ID
authors.lastname: Samuel
authors.affiliation: Physics Department and Center for Optoelectronics and Photonics Paderborn (CeOPP), Universität Paderborn , Warburger Strasse 100, 33098 Paderborn, Germany.
authors.forename: Stefan
authors.identifier: http://orcid.org/0000-0003-4042-4951
authors.initials: S
authors.lastname: Schumacher