Hole Catalysis as a General Mechanism for Efficient and Wavelength-Independent Z -> E Azobenzene Isomerization
| Autor: | Clemens Rietze, Leonora Abdullahu, Evgenii Titov, Lutz Grubert, Alexis Goulet-Hanssens, Stefan Hecht, Peter Saalfrank |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Materials science 010405 organic chemistry General Chemical Engineering Biochemistry (medical) General Chemistry Electron acceptor 010402 general chemistry Electrochemistry Photochemistry Electrocatalyst 01 natural sciences Biochemistry 0104 chemical sciences Catalysis chemistry.chemical_compound Wavelength chemistry Azobenzene ddc:540 Materials Chemistry Environmental Chemistry Institut für Chemie Absorption (chemistry) Isomerization |
| Popis: | Summary Whereas the reversible reduction of azobenzenes has been known for decades, their oxidation is destructive and as a result has been notoriously overlooked. Here, we show that a chain reaction leading to quantitative Z → E isomerization can be initiated before reaching the destructive anodic peak potential. This hole-catalyzed pathway is accessible to all azobenzenes, without exception, and offers tremendous advantages over the recently reported reductive, radical-anionic pathway because it allows for convenient chemical initiation without the need for electrochemical setups and in the presence of air. In addition, catalytic amounts of metal-free sensitizers, such as methylene blue, can be used as excited-state electron acceptors, enabling a shift of the excitation wavelength to the far red of the azobenzene absorption (up to 660 nm) and providing quantum yields exceeding unity (up to 200%). Our approach will boost the efficiency and sensitivity of optically dense liquid-crystalline and solid photoswitchable materials. Video Abstract |
| Databáze: | OpenAIRE |
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