Regensburg 2013 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 24: Organic Semiconductors
CPP 24.9: Vortrag
Mittwoch, 13. März 2013, 12:00–12:15, H40
Model systems for interchromophoric interactions in conjugated polymer materials — •Thomas Stangl1, Sebastian Bange1, Daniela Schmitz2, Dominik Würsch1, Sigurd Höger2, Jan Vogelsang1, and John M. Lupton1 — 1Universität Regensburg, Regensburg, Deutschland — 2Universität Bonn, Bonn, Deutschland
A set of pi-conjugated oligomer dimers templated in molecular scaffolds is presented as a model system of the interactions between chromophores in conjugated polymers. Single-molecule spectroscopy was used to reveal energy transfer dynamics and electronic aggregation between two oligomers in either parallel conformation with different well-defined distances or oblique-angle geometry. First, it is concluded that the model systems presented here can be used to investigate the impact of H-aggregation as a function of interchromophoric distance by lifetime and single-molecule spectral measurements. Second, the long-term non-equilibrium dynamics of energy transfer within the weakly coupled bichromophoric systems, however, is found to be accessible by studying the linear dichroism in emission at the single-molecule level, revealing reversible switching of the emission between the two oligomers. In bulk polymer films, strong and weak interchromophoric coupling impacts the functionality, e.g. the emission colour and the migration of excitation energy to quenching sites. Realizing the presence and dynamics of such interactions is crucial for understanding limitations in quantum efficiency of larger conjugated polymer materials.