Berlin 2014 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 17: Excitons and Excitation Transfer (SYET 2)
MO 17.3: Vortrag
Donnerstag, 20. März 2014, 14:45–15:00, BEBEL HS213
Exciton coupling effects in polymeric cis-indolenine squaraine dyes — •Federico Koch1, Sebastian Völker2, Christoph Lambert2, and Tobias Brixner1 — 1Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg — 2Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg
Polymeric cis-indolenine squaraine (pSQ) dye compounds display a broad absorption in the red-to-NIR region with disctinct maxima but a narrow fluorescence. The energetic shifts of the absorption maxima corresponding to the monomer can be explained by a mixture of H- and J-type alignment of chromophores [1].
We investigated the exciton coupling of pSQ in DCM (predominantly J-type alignment) and DMF (predominantly H-type alignment) by femtosecond transient absorption (TA) and coherent two-dimensional (2D) spectroscopy. In the TA studies we observed ultrafast relaxation dynamics ranging from fs to ns. The fast dynamics probably relate to an excitonic coupling. With 2D spectroscopy we aim at the direct characterization of the coupling and the corresponding interaction between the excitonic states.
S. F. Völker, and C. Lambert, Chem. Mat. 2012, 24, 2541-2553