Microphasic separation-induced enantiotropic liquid crystal behaviour single phenyl unit series based on the fluorophobic effect
| Autor: | S. Ge´Ribaldi, G. Fornasieri, F. Guittard |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
chemistry.chemical_classification
Polarized light microscopy Materials science Hydrogen bond General Chemistry Atmospheric temperature range Condensed Matter Physics Crystallography chemistry.chemical_compound Differential scanning calorimetry chemistry Liquid crystal Alkoxy group Phenyl group Organic chemistry General Materials Science Alkyl |
| Zdroj: | Liquid Crystals. 30:663-669 |
| ISSN: | 1366-5855 0267-8292 |
| Popis: | The aim of this work was to demonstrate the possibility of obtaining enantiotropic liquid crystals containing a single phenyl group over a wide temperature range but without hydrogen bonding. We report the synthesis and characterization of several alkoxy monophenyl compounds linked by a thioester group to a 2-(perfluoro-n alkyl) ethyl chain. Compared with previous work using monophenyl cores, the synthetic pathway provides compounds is high yields from cheaper raw materials, i.e. 4-hydroxybenzoic acid. The mesomorphic properties were characterized using polarized light microscopy and differential scanning calorimetry. The effects of lengthening the substituents on the phenyl core were considered: varying the length of the alkyloxy groups had a marked effect, with the formation of enantiotropic mesomorphic phases with a maximum temperature range of 70°C. The temperature range of the mesomorphic phase is inversely proportional to the length of the alkyl chain and exhibits an odd-even effect. Decreasing the ... |
| Databáze: | OpenAIRE |
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