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Photo‐Driven Chirality Switching in a Dark Conglomerate Phase of an Achiral Liquid Crystal Trimer
Author(s) -
Sasaki Haruna,
Takanishi Yoichi,
Yamamoto Jun,
Yoshizawa Atsushi
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201800067
Subject(s) - trimer , materials science , bent molecular geometry , liquid crystal , phase (matter) , crystallography , chirality (physics) , phase transition , crystal (programming language) , chemical physics , condensed matter physics , dimer , chemistry , physics , optoelectronics , symmetry breaking , chiral symmetry breaking , organic chemistry , quantum mechanics , nambu–jona lasinio model , composite material , computer science , programming language
Chiral conglomerate phases possessing a saddle‐splay curvature have attracted much attention from researchers. A rigid bent shape is recognized to be necessary for their formations, as the tilted orientation of the bent‐core molecules in the layers drives the layers to twist, producing the saddle‐splay curvature. We prepared an achiral liquid crystal trimer, 2‐{4‐[9‐(4‐(4‐octyloxyazobenzene‐4’‐yloxy)nonyloxy)phenyl]‐5‐{9‐[4‐(5‐octyloxypyrimidin‐2‐yl)phenyloxy]nonyloxy}pyrimidine, and investigated the thermal transitions and the photo‐induced isothermal transitions. The trimer exhibited nematic and dark chiral conglomerate (DC) phases. When the trimer was exposed to UV light with wavelength 365 nm in the soft crystalline DC phase, it changed to an achiral liquid crystalline phase consisting of short correlation length layer structures. The photo‐induced phase did not appear in the thermal phase sequence. In light of this, we discuss how this photo‐driven on/off switching of the chirality occurs. Furthermore, we show that it can be applied to control the nanostructure of the DC phase.