Journal article
Solvent tuning of photochemistry upon excited-state symmetry breaking.
- Dereka B Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
- Svechkarev D Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, 68198-6858, USA.
- Rosspeintner A Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
- Aster A Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
- Lunzer M Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163/MC, 1060, Vienna, Austria.
- Liska R Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163/MC, 1060, Vienna, Austria.
- Mohs AM Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, 68198-6858, USA.
- Vauthey E Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland. eric.vauthey@unige.ch.
- 2020-04-23
Published in:
- Nature communications. - 2020
General Biochemistry, Genetics and Molecular Biology
General Physics and Astronomy
General Chemistry
English
The nature of the electronic excited state of many symmetric multibranched donor-acceptor molecules varies from delocalized/multipolar to localized/dipolar depending on the environment. Solvent-driven localization breaks the symmetry and traps the exciton in one branch. Using a combination of ultrafast spectroscopies, we investigate how such excited-state symmetry breaking affects the photochemical reactivity of quadrupolar and octupolar A-(π-D)2,3 molecules with photoisomerizable A-π-D branches. Excited-state symmetry breaking is identified by monitoring several spectroscopic signatures of the multipolar delocalized exciton, including the S2 ← S1 electronic transition, whose energy reflects interbranch coupling. It occurs in all but nonpolar solvents. In polar media, it is rapidly followed by an alkyne-allene isomerization of the excited branch. In nonpolar solvents, slow and reversible isomerization corresponding to chemically-driven symmetry breaking, is observed. These findings reveal that the photoreactivity of large conjugated molecules can be tuned by controlling the localization of the excitation.
- Language
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- English
- Open access status
- gold
- Identifiers
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- DOI 10.1038/s41467-020-15681-3
- PMID 32317631
- Persistent URL
- https://sonar.ch/global/documents/103747
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