Expanding excitation wavelengths for azobenzene photoswitching into the near-infrared range
| Autor: | Jussi, Isokuortti, Kim, Kuntze, Matti, Virkki, Zafar, Ahmed, Elina, Vuorimaa-Laukkanen, Mikhail A, Filatov, Andrey, Turshatov, Timo, Laaksonen, Arri, Priimagi, Nikita A, Durandin |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Chemical Science |
| ISSN: | 2041-6520 |
| Popis: | Developing azobenzene photoswitches capable of selective and efficient photoisomerization by long-wavelength excitation is an enduring challenge. Herein, rapid isomerization from the Z- to E-state of two ortho-functionalized bistable azobenzenes with near-unity photoconversion efficiency was driven by triplet energy transfer upon red and near-infrared (up to 770 nm) excitation of porphyrin photosensitizers in catalytic micromolar concentrations. We show that the process of triplet-sensitized isomerization is efficient even when the sensitizer triplet energy is substantially lower (>200 meV) than that of the azobenzene used. This makes the approach applicable for a wide variety of sensitizer-azobenzene combinations and enables the expansion of excitation wavelengths into the near-infrared spectral range. Therefore, indirect excitation via endothermic triplet energy transfer provides efficient and precise means for photoswitching upon 770 nm near-infared light illumination with no chemical modification of the azobenzene chromophore, a desirable feature in photocontrollable biomaterials. Triplet energy transfer enables efficient Z-to-E photoswitching of azobenzenes even with near-infrared light. Ultrafast intersystem crossing of azobenzene makes the process entropy-driven and enables the use of endothermic sensitizer-azobenzene pairs. |
| Databáze: | OpenAIRE |
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