Self-assembled discotic nematic liquid crystals formed by simple hydrogen bonding between phenol and pyridine moieties

    Authors

    J. H. Lee; I. Jang; S. H. Hwang; S. J. Lee; S. H. Yoo;J. Y. Jho

    Comments

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    Abbreviated Journal Title

    Liq. Cryst.

    Keywords

    discotic nematic; liquid crystal; self-assembly; single hydrogen bonding; DIMENSIONAL ELECTRONIC CONDUCTIVITY; MESOMORPHIC PROPERTIES; COLUMNAR; MESOPHASES; SIDE-CHAIN; DERIVATIVES; MESOGENS; POLYMER; PHASE; ALKOXYSTILBAZOLES; INDUCTION; Chemistry, Multidisciplinary; Crystallography; Materials Science, ; Multidisciplinary

    Abstract

    New discotic nematic liquid crystals have been prepared through intermolecular hydrogen bonding between the core of 1,3,5-trihydroxybenzene (phloroglucinol, PG) or 1,3,5-tris(4-hydroxyphenyl)benzene (THPB) and the peripheral molecules of stilbazole derivatives. The various nematic phases formed by new hydrogen bonding building blocks were investigated by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. The first discotic complexes of PG and trans-4-alkoxy-4'-stilbazoles exhibited nematic columnar (N-C) and hexagonal columnar phases depending on the length of alkyl chains, which were considered as the basic discotic structure. Several structural variations on the building blocks were attempted to examine their effects on the liquid crystalline properties of discotic complexes. The nematic lateral phase (N-L) with enhanced intercolumnar order was observed for the complexes of PG and trans-4-cyanoalkoxy-4' stilbazoles due probably to the strong dipole interactions between cyano groups at the end of alkoxy chains. By introducing the nonlinear structure in three arms of supramolecular discotic mesogen, a discotic nematic phase (N-D) was observed for the complex of THPB and trans-4-octyloxy-4-stilbazole. The single hydrogen bonding between phenol and pyridine moieties in this study provides a simple and effective method for preparing the rarely found discotic nematic liquid crystals.

    Journal Title

    Liquid Crystals

    Volume

    39

    Issue/Number

    8

    Publication Date

    1-1-2012

    Document Type

    Article

    Language

    English

    First Page

    973

    Last Page

    981

    WOS Identifier

    WOS:000305759000009

    ISSN

    0267-8292

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