Ammenhaeuser, Robin and Klein, Patrick and Schmid, Eva and Streicher, Sabrina and Vogelsang, Jan and Lehmann, Christian W. and Lupton, John M. and Meskers, Stefan C. J. and Scherf, Ullrich (2023) Circularly Polarized Light Probes Excited-State Delocalization in Rectangular Ladder-type Pentaphenyl Helices. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 62 (2): e202211946. ISSN 1433-7851, 1521-3773
Full text not available from this repository. (Request a copy)Abstract
Ladder-type pentaphenyl chromophores have a rigid, planar pi-system and show bright fluorescence featuring pronounced vibrational structure. Such moieties are ideal for studying interchromophoric interactions and delocalization of electronic excitations. We report the synthesis of helical polymers with a rigid square structure based on spiro-linked ladder-type pentaphenyl units. The variation of circular dichroism with increasing chain length provides direct evidence for delocalization of electronic excitations over at least 10 monomeric units. The change in the degree of circular polarization of the fluorescence across the vibronic side bands shows that vibrational motion can localize the excitation dynamically to almost one single unit through breakdown of the Born-Oppenheimer approximation. The dynamic conversion between delocalized and localized excited states provides a new paradigm for interpreting circular dichroism in helical polymers such as proteins and polynucleic acids.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CHAIN-LENGTH; DYNAMIC LOCALIZATION; POLYMER SYNTHESIS; DICHROISM; LUMINESCENCE; SPECTROSCOPY; PHOTOPHYSICS; ABSORPTION; EXCITATION; SPECTRA; Chirality; Circular Dichroism; Circular Polarization of Luminescence; Helical Ladder Polymers; Spiro Bisfluorene Linkers |
| 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: | 09 Apr 2024 04:56 |
| Last Modified: | 09 Apr 2024 04:56 |
| URI: | https://pred.uni-regensburg.de/id/eprint/60616 |
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