Asymmetric Dimers of Chiral Azobenzene Dopants Exhibiting Unusual Helical Twisting Power upon Photoswitching in Cholesteric Liquid Crystals

ACS Applied Materials & Interfaces
Yuna Kim, Nobuyuki Tamaoki

Abstract

In this study, we synthesized asymmetric dimeric chiral molecules as photon-mode chiral switches for reversible tuning of self-assembled helical superstructures. The chiral switches bearing two mesogen units-cholesterol and azobenzene moieties connected through flexible alkylenedioxy bridges-were doped into nematic liquid crystals, resulting in a chiral nematic (cholesteric) phase. Under irradiation with UV light, photoisomerization of the azobenzene units led to unprecedented switching of the cholesteric pitch and helical twisting power (HTP, β), with a higher HTP found in the cis-rich state (bent-form) than in the trans-state (rod-form). We attribute this behavior to the elongated cybotactic smectic clusters disrupting the helical orientation of the molecules in the cholesteric liquid crystals; their reversible decay and reassembly was evidenced upon sequential irradiation with UV and visible light, respectively. In addition to the photoisomerization of the azobenzene units, the odd/even parity of the alkylenedioxy linkers of the dimeric dopants also had a dramatic effect on the transitions of the cybotactic smectic domains. On the basis of the large rotational reorganization of the cholesteric helix and HTP switching (Δβ/βin...Continue Reading

References

Oct 8, 2004·Chemistry : a European Journal·Silvia PieracciniGian Piero Spada
Mar 10, 2006·Nature·Rienk EelkemaBen L Feringa
Mar 24, 2006·Nature·Takahiro MuraokaTakuzo Aida
Oct 7, 2006·Organic & Biomolecular Chemistry·Rienk Eelkema, Ben L Feringa
Nov 2, 2006·Journal of the American Chemical Society·Rienk EelkemaBen L Feringa
Oct 12, 2007·Journal of the American Chemical Society·Quan LiJ William Doane
Oct 9, 2008·Journal of the American Chemical Society·Alessandro BoscoBen L Feringa
Feb 23, 2010·Optics Express·Timothy J WhiteTimothy J Bunning
Jan 6, 2011·Chemistry : a European Journal·Abu KausarSeiji Kurihara
Mar 14, 2012·Advanced Materials·Yan Wang, Quan Li
May 19, 2012·Nature·Tamas KosaTimothy J Bunning
Sep 6, 2013·Proceedings of the National Academy of Sciences of the United States of America·Dong ChenNoel A Clark
Nov 6, 2013·Nature Communications·V BorshchO D Lavrentovich
Sep 3, 2014·Accounts of Chemical Research·Hari Krishna Bisoyi, Quan Li

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Citations

Dec 6, 2016·Chemical Communications : Chem Comm·Yuna KimNobuyuki Tamaoki
Sep 14, 2019·Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry·B N VeerabhadraswamyChannabasaveshwar V Yelamaggad
Feb 28, 2018·Physical Chemistry Chemical Physics : PCCP·Xiqian WangJianzhuang Jiang
Oct 9, 2018·Journal of the American Chemical Society·Mark J MoranIvan Aprahamian
Apr 2, 2019·ACS Applied Materials & Interfaces·Noushaba Nusrat MafyNobuyuki Tamaoki
Oct 1, 2021·Journal of the American Chemical Society·Sirun YangIvan Aprahamian

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