The azulene ring as a structural element in liquid crystals
Autor: | Siân E. Estdale, David A. Dunmur, Roger Brettle, Charles M. Marson |
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Rok vydání: | 1997 |
Předmět: | |
Zdroj: | Journal of Materials Chemistry. 7:391-401 |
ISSN: | 1364-5501 0959-9428 |
DOI: | 10.1039/a606139g |
Popis: | A new approach to the synthesis of azulene liquid crystals is described based on Hafner’s procedure involving reaction of a pyridinium salt with a cyclopentadienide. The preparation of a variety of liquid crystalline materials using this method is described. Variants are reported with single substituents on the azulene ring in the 6-position and doubly substituted in the 2, 6- positions. The effect of the azulene ring as a core or dipolar terminal structural element is explored. 6-(5-Alkyl-1,3-dioxan-2-yl)azulenes are shown to exhibit smectic A phases and 2-cyclohexyl-6-(5-tridecyl-1,3-dioxan-2-yl)azulene show smectic A and B phases. Phase characterisation of the materials is recorded together with X-ray measurements on the smectic A phase of one representative compound. Results of dichroism studies on the azulene mesogens are also briefly reviewed. |
Databáze: | OpenAIRE |
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