Abstract
We have found that the discotic nematic liquid crystal, hexakis(4-nonylphenylethynyl)benzene (HNEB), doped with the racemic chromium complex Cr(Ocacac) 3 , shows a novel straight-needle texture with hexagonal columnar alignments, changing to a curved-needle texture under irradiation of circularly polarized light (CPL). This novel phenomenon is specific to the mixture of HNEB and Cr(Ocacac) 3 . The formation of curved needles means that chiroselective photoinversion of racemic Cr(Ocacac) 3 by CPL irradiation induces a needle direction change in a discotic liquid crystal. The change in chirality of Cr(Ocacac) 3 in HNEB induced by CPL irradiation, and the resulting nano-segregation of its enantiomers during cooling from the isotropic to mesophase of HNEB, are considered to influence changes in the alignment of columns and/or small domains of column aggregates in the discotic liquid crystal.
Original language | English |
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Pages (from-to) | 671-679 |
Number of pages | 9 |
Journal | Liquid Crystals |
Volume | 33 |
Issue number | 6 |
DOIs | |
State | Published - 1 Jun 2006 |
Externally published | Yes |