Towards low-energy-light-driven bistable photoswitches
- Thermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure-property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV upThermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure-property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days. <br /> [GRAPHICS] <br /> .…
Author details: | Kim Kuntze, Jani Viljakka, Evgenii TitovORCiDGND, Zafar AhmedORCiDGND, Elina KaleniusORCiD, Peter SaalfrankORCiDGND, Arri PriimagiORCiD |
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DOI: | https://doi.org/10.1007/s43630-021-00145-4 |
ISSN: | 1474-905X |
ISSN: | 1474-9092 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/34888753 |
Title of parent work (English): | Photochemical & photobiological sciences / European Society for Photobiology |
Subtitle (English): | ortho-fluoroaminoazobenzenes |
Publisher: | Springer |
Place of publishing: | Heidelberg |
Publication type: | Article |
Language: | English |
Date of first publication: | 2022/12/10 |
Publication year: | 2022 |
Release date: | 2024/04/12 |
Volume: | 21 |
Issue: | 2 |
Number of pages: | 15 |
First page: | 159 |
Last Page: | 173 |
Funding institution: | H2020 European Research Council [679646]; Luonnontieteiden ja Tekniikan Tutkimuksen Toimikunta [321065]; Graduate School, Tampere University; Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [454020933] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie |
6 Technik, Medizin, angewandte Wissenschaften / 62 Ingenieurwissenschaften / 620 Ingenieurwissenschaften und zugeordnete Tätigkeiten | |
Peer review: | Referiert |
Publishing method: | Open Access / Hybrid Open-Access |
License (German): | CC-BY - Namensnennung 4.0 International |