Berlin 2001 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
CPP: Chemische Physik und Polymerphysik
CPP 16: Poster: Dynamics of Molecular Systems, Polymer Dynamics, Glass Transition, Crystallization, Electronic Properties of Polymers
CPP 16.3: Poster
Montag, 2. April 2001, 12:30–15:00, AT1
Femtosecond Charge Transfer Dynamics in Conjugated D/A Systems: Switching from Adiabatic to Nonadiabatic Regimes through Small Structural Changes — •T. Fiebig1, T. Bizjak2, S. Lochbrunner2, J. Piel2, K. Stock2, and E. Riedle2 — 1Institut f. Physikalische u. Theoretische Chemie, TU Muenchen, Garching — 2LS BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universitaet Muenchen
The dynamics of intramolecular charge transfer (CT) in a family of conjugated donor/acceptor (D/A) systems have been studied by femtosecond transient absorption spectroscopy. Although these compounds have very similar structures we observed vastly different CT dynamics, ranging from a few 100 fs to tens of nanoseconds. These results implicate that specific modifications in the substitution scheme can lead to alternations of the relevant D/A orbitals and thus to drastic changes in the excited state electronic delocalization. The results are entirely consistent with previous steady state experiments [Fiebig et al., Chem.Phys.Lett. 282 (1998) 7-15]. They also demonstrate the importance of the electronic D/A-coupling and its dependence on the topology of the relevant orbitals, for both CT dynamics and fluorescence properties of aromatic D/A-systems.