| Autor: |
Allolio C, Stangl T, Eder T, Schmitz D; Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn , Gerhard-Domagk-Str. 1 , 53121 Bonn , Germany., Vogelsang J, Höger S; Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn , Gerhard-Domagk-Str. 1 , 53121 Bonn , Germany., Horinek D, Lupton JM |
| Jazyk: |
angličtina |
| Zdroj: |
The journal of physical chemistry. B [J Phys Chem B] 2018 Jun 21; Vol. 122 (24), pp. 6431-6441. Date of Electronic Publication: 2018 Jun 12. |
| DOI: |
10.1021/acs.jpcb.8b01188 |
| Abstrakt: |
Excited-state interchromophoric couplings in π-conjugated polymers present a daunting challenge to study as their spectroscopic signatures are difficult to separate from structure-dependent intrachromophoric spectral characteristics. Using custom-designed molecular model systems in combination with single-molecule spectroscopy, a controlled coupling of the excited states between cofacially arranged π-conjugated oligomers is shown to be possible. Multiscale molecular dynamics simulations allow us to generate a representative ensemble of molecular structures of the model molecule embedded in a polymer matrix and examine the connection between structural fluctuations of the molecule with theoretically predicted and measured spectral signatures. The single molecules in the embedding matrix polymer can be assigned to specific conformational features with the help of computer-based "virtual spectroscopy". By combining a quantum chemical approach with an analytical approach, we show that the coupling between the chromophores is well-described by transition dipole coupling above an interchromophoric separation of ∼4.5 Å. Even for aligned chromophores, however, twisting between repeat units of the π-system and bending of the individual π-systems can lead to a decoupling of the chromophores to a degree far beyond what their equilibrium structures would suggest: tiny displacements of the molecular constituents can dramatically impact excited-state interactions. This observation has profound implications for the design of future tunable organic optoelectronic materials. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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