Cooperative Switching in Nanofibers of Azobenzene Oligomers
Autor: | Linus Pithan, Jürgen P. Rabe, Stefan Hecht, C. Weber, Tobias Liebig, Anton Zykov, Manuel Gensler, David Bléger, Stefan Kowarik |
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Jazyk: | angličtina |
Rok vydání: | 2016 |
Předmět: |
Molecular switch
Multidisciplinary Materials science Photoisomerization Intermolecular force Supramolecular chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Bioinformatics 01 natural sciences Article 0104 chemical sciences Coupling (electronics) Photochromism chemistry.chemical_compound Chemical engineering Azobenzene chemistry Nanofiber 0210 nano-technology |
Zdroj: | Scientific Reports |
ISSN: | 2045-2322 |
Popis: | Next-generation molecular devices and machines demand the integration of molecular switches into hierarchical assemblies to amplify the response of the system from the molecular level to the meso- or macro-scale. Here, we demonstrate that multi-azobenzene oligomers can assemble to form robust supramolecular nanofibers in which they can be switched repeatedly between the E- and Z-configuration. While in isolated oligomers the azobenzene units undergo reversible photoisomerization independently, in the nanofibers they are coupled via intermolecular interactions and switch cooperatively as evidenced by unusual thermal and kinetic behavior. We find that the photoisomerization rate from the Z-isomer to the E-isomer depends on the fraction of Z-azobenzene in the nanofibers and is increased by more than a factor of 4 in Z-rich fibers when compared to E-rich fibers. This demonstrates the great potential of coupling individual photochromic units for increasing their quantum efficiency in the solid state with potential relevance for actuation and sensing. |
Databáze: | OpenAIRE |
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