Visible-Light-Induced Self-Organized Helical Superstructure in Orientationally Ordered Fluids
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
| Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - 31(2019), 39 vom: 02. Sept., Seite e1902958 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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| Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
| Schlagworte: | Journal Article cyclic-azobenzene chiral molecular switches diffraction gratings helix induction stimuli-responsive materials visible-light-driven photoisomerization |
| Zusammenfassung: | © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Light-induced phenomena occurring in nature and in synthetic materials are fascinating and have been exploited for technological applications. Here visible-light-induced formation of a helical superstructure is reported, i.e., a cholesteric liquid crystal phase, in orientationally ordered fluids, i.e., nematic liquid crystals, enabled by a visible-light-driven chiral molecular switch. The cyclic-azobenzene-based chiral molecular switch exhibits reversible photoisomerization in response to visible light of different wavelengths due to the band separation of n-π* transitions of its trans- and cis-isomers. Green light (530 nm) drives the trans-to-cis photoisomerization whereas the cis-to-trans isomerization process of the chiral molecular switch can be caused by blue light (440 nm). It is observed that the helical twisting power of this chiral molecular switch increases upon irradiation with green light, which enables reversible induction of helical superstructure in nematic liquid crystals containing a very small quantity of the molecular switch. The occurrence of the light-induced helical superstructure enables the formation of diffraction gratings in cholesteric films |
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| Beschreibung: | Date Completed 30.09.2019 Date Revised 30.09.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.201902958 |