Berlin 2012 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 11: New Instruments and Methods
CPP 11.2: Talk
Tuesday, March 27, 2012, 10:00–10:15, C 243
Excitation Energy Transfer and Optical Properties of Supramolecular Complexes: A Mixed Quantum Classical Methodology — •Jörg Megow1, Alexander Kulesza2, Beate Röder1, Roland Mitric2, and Volkhard May1 — 1Institut für Physik, Humboldt-Universität zu Berlin, Germany — 2Institut für Physik, Freie Universität Berlin, Germany
Excitation energy transfer and optical properties of large chromophore complexes are studied using a mixed quantum classical methodology. The chromophore complex is formed by a butanediamine dendrimer to which sixteen pheophorbide-a (Pheo) molecules are covalently linked (P16). While the nuclear coordinates are described classically by carrying out room-temperature MD-simulations the electronic excitations are treated quantum mechanically by solving the time-dependent Schrödinger equation. The energy gap fluctuation due to intramolecular vibration was calculated utilizing a harmonic approximation. The solute-solvent coupling is treated by Coulomb interaction.
Using the energy gap fluctuation, linear absorbance and pump-probe-spectra of P16 are calculated and compared to earlier results calculated for a single Pheo [1] and P4 [2,3]. The effect of the excitonic coupling between the chromophores in P16 was analized in comparison with the results for a single Pheo and P4.
[1] J. Megow et al., Chem. Phys. 377, 10 (2010)
[2] J. Megow et al., ChemPhysChem 12, 645 (2011)
[3] J. Megow et al., Chem. Phys. Lett. (in press)