Ultrafast electronic energy transfer in an orthogonal molecular dyad
journal contributionposted on 16.03.2018, 13:52 by Christian Wiebeler, Felix Plasser, Gordon J. Hedley, Arvydas Ruseckas, Ifor D. W. Samuel, Stefan Schumacher
© 2017 American Chemical Society. 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.
C.W. and S.S. thank the German Research Foundation (DFG: GRK 1464) for financial support and PC2 for computing time. S.S. acknowledges support through the Heisenberg programme of the DFG. F.P. acknowledges support by the VSC Research Center funded by the Austrian Federal Ministry of Science, Research, and Economy (bmwfw). The St Andrews group acknowledges support from the European Research Council (grant number 321305) and the Engineering and Physical Sciences Research Council (grant EP/L017008/1). I.D.W.S. also acknowledges support from a Royal Society Wolfson Research Merit Award.