Chiral ordering in the nematic and an optically isotropic mesophase of bent-core mesogens with a halogen substituent at the central core
| Autor: | Wolfgang Weissflog, Siegmar Sokolowski, Heinz Dehne, Banani Das, Siegbert Grande, Martin W. Schröder, Alexey Eremin, Siegmar Diele, Gerhard Pelzl, Horst Kresse |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Materials science
Isotropy Substituent Mesophase General Chemistry Nuclear magnetic resonance spectroscopy Condensed Matter Physics chemistry.chemical_compound Crystallography Homologous series Differential scanning calorimetry chemistry Liquid crystal Phase (matter) Organic chemistry General Materials Science |
| Zdroj: | Liquid Crystals. 31:923-933 |
| ISSN: | 1366-5855 0267-8292 |
| Popis: | Two new homologous series of bent-core compounds have been synthesized. Their mesophase behaviour has been investigated by polarizing microscopy, differential scanning calorimetry, X-ray diffraction, NMR spectroscopy, and by dielectric and electro-optical measurements. It was found that, with one exception, all the chlorine-substituted compounds form a nematic phase and an optically isotropic ‘banana phase’. The latter phase shows spontaneously chiral domains of opposite handedness. This phase may be considered as a type of smectic blue phase. The mesophase behaviour of the homologous bromine-substituted compounds is more complicated. Depending on the chain length, B6, columnar, nematic or the isotropic ‘banana phase’ occur. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|