Title

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

Authors

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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