- Self-assembly of chiral mesoionic heterocycles into smectic phases: A new class of polar liquid crystal
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The molecular design, synthesis and characterization of the first examples of both classical and non-conventional chiral mesoionic (mesomeric + ionic) liquid crystals derived from sydnones are described. The occurrence of chiral smectic phases in these no
- Yelamaggad,Mathews, Manoj,Hiremath, Uma S.,Shankar Rao,Krishna Prasad
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p. 2623 - 2626
(2007/10/03)
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- Influence of fluoro substituents on the mesophase behaviour of banana-shaped molecules
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Three new series of bent-shaped five-ring liquid crystals, based on the ester of isophthalic acid as the central core and azomethine linkages, are presented. They differ by the number and the position of halogeno substituents on the outer rings. This lateral substitution strongly influences the type of mesophases formed. Calculations were performed to determine the modification of the distribution of charge along the different molecules.
- Bedel,Rouillon,Marcerou,Laguerre,Nguyen,Achard
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p. 2214 - 2220
(2007/10/03)
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- Chiral cyclohexyl compounds
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The present invention describes liquid crystal compounds which are suitable for use in liquid crystal devices including those which exploit the electroclinic effect.
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- Liquid crystal compounds and compositions
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Liquid crystal naphthalene compounds, represented by the following formula (1) are disclosed. R-Z-A- -NAP-Z?-R? (1)In the formula (1), R is an alkyl group containing 1 to 18 carbon atoms; R? is an alkyl group containing 1 to 21 carbon atoms; NAP represents 2,6-naphthylene group; represents C≡C;, A, Z and Z? are as follows: 1) A is Pyr> and, (a) Z is - and Z? is O or COO or (b) Z is OCO and Z? is - or O; 2) A is FPhF and (a) Z is - or O and Z? is -, O or COO or (b) Z is OCO and Z? is - or O; 3) A is FPh and (a) Z is - and Z? is O or COO, (b) Z is O and Z? is -, O or COO or (c) Z is OCO and Z? is - or O; 4) A is Pyr and Z is - or O and Z? is COO; or 5) A is PhF and Z is O and Z? is -; wherein: When used as a component of liquid crystal composition showing ciral smectic C phase, these compounds can provide liquid crystal compositions of improved orientation and free from zigzag deffects, and liquid crystal display elements of high contrast ratio.
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- 67. Ferroelectric Liquid Crystals. Laterally Substituted Phenyl Benzoates Incorporating a trans-1,4-Disubstituted Cyclohexane Ring.
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About 65 diverse phenyl benzoates incorporating a trans-1,4-disubstituted cyclohexane ring and at least one lateral substituent have been synthesised.The dependence of the liquid-crystal transition temperatures of these materials on various lateral substituents (F, Cl, CN, and Br) in different positions of the esters has been investigated systematically.The influence of up to four F-atoms in various positions of a standard ester has been thoroughly studied and the optimum combination for a broad smectic C mesomorphic range established.In consequence, three homologous series incorporating the 4-alkoxy-2,3-difluorobenzoic-acid moiety were prepared.An additional C=C bond was introduced into the alkyl chain attached to the cyclohexane ring of some of these esters and the resulting modifications of the transition temperatures determined.Three ester series incorporating a lateral substituent and the optically active (+)-(S)-(1-methylphenyl)oxy substituent have also been synthesised, and similar effects have been observed.These materials can be used as important components of commercial chiral smectic C mixtures for electro-optic display device applications.
- Kelly, Stephen M.
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p. 594 - 607
(2007/10/02)
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