Aggarwal, A. Vikas and Thiessen, Alexander and Idelson, Alissa and Kalle, Daniel and Wuersch, Dominik and Stangl, Thomas and Steiner, Florian and Jester, Stefan-S. and Vogelsang, Jan and Hoeger, Sigurd and Lupton, John M. (2013) Fluctuating exciton localization in giant pi-conjugated spoked-wheel macrocycles. NATURE CHEMISTRY, 5 (11). pp. 964-970. ISSN 1755-4330, 1755-4349
Full text not available from this repository. (Request a copy)Abstract
Conjugated polymers offer potential for many diverse applications, but we still lack a fundamental microscopic understanding of their electronic structure. Elementary photoexcitations (excitons) span only a few nanometres of a molecule, which itself can extend over microns, and how their behaviour is affected by molecular dimensions is not immediately obvious. For example, where is the exciton formed within a conjugated segment and is it always situated on the same repeat units? Here, we introduce structurally rigid molecular spoked wheels, 6 nm in diameter, as a model of extended pi conjugation. Single-molecule fluorescence reveals random exciton localization, which leads to temporally varying emission polarization. Initially, this random localization arises after every photon absorption event because of temperature-independent spontaneous symmetry breaking. These fast fluctuations are slowed to millisecond timescales after prolonged illumination. Intramolecular heterogeneity is revealed in cryogenic spectroscopy by jumps in transition energy, but emission polarization can also switch without a spectral jump occurring, which implies long-range homogeneity in the local dielectric environment.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | SINGLE-MOLECULE SPECTROSCOPY; LIGHT-HARVESTING COMPLEXES; ENERGY-TRANSFER; POLARIZATION SPECTROSCOPY; PHOTOSYNTHETIC ANTENNA; POLYMERS; FLUORESCENCE; RING; PORPHYRIN; SYSTEMS; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Lupton > Group John Lupton |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 01 Apr 2020 10:57 |
| Last Modified: | 01 Apr 2020 10:57 |
| URI: | https://pred.uni-regensburg.de/id/eprint/15785 |
Actions (login required)
 |
View Item |
