Liquid crystalline compound

Compounds with two mesogenic groups with and without terminal alkyl chains containing thiophene rings (cf. Sect. 1.2) are described [8-10,462]. The liquid crystalline behavior of the various compounds is dependent on the length of the 

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Table 2. Some Central Linkages Found in Liquid Crystalline Compounds...

Liquid crystalline compounds are not very dangerous and only basic precautions should be used in handling them. They are not poisonous or carcinogenic, and do not cause problems when in contact with skin (see also Biphenyls and terphenyls Cinnamic acid Stilbene dyes). 

Kanayama, N., Tsutsumi, O., Kanazawa, A. and Ikeda, T. (2001) Distinct thermodynamic behaviour of a mesomorphic gold nanoparticle covered with a liquid-crystalline compound. Chemical Communications, (24), 2640-2641. 

Scheme 6.45 MW-assisted synthesis of S-heterocycle-containing liquid crystalline compounds.

Liquid crystal display technology, 15 113 Liquid crystalline cellulose, 5 384-386 cellulose esters, 5 418 Liquid crystalline conducting polymers (LCCPs), 7 523-524 Liquid crystalline compounds, 15 118 central linkages found in, 15 103 Liquid crystalline materials, 15 81-120 applications of, 15 113-117 availability and safety of, 15 118 in biological systems, 15 111-113 blue phases of, 15 96 bond orientational order of, 15 85 columnar phase of, 15 96 lyotropic liquid crystals, 15 98-101 orientational distribution function and order parameter of, 15 82-85 polymer liquid crystals, 15 107-111 polymorphism in, 15 101-102 positional distribution function and order parameter of, 15 85 structure-property relations in,... 

Thermostats, mercury-switch, 16 42 Thermosyphon, 13 225, 226 Thermosyphon reboiler, 11 774 Thermotropic LCPs, 13 381-382 Thermotropic liquid crystalline compounds, 15 87-89t... 

Note 3 Sequences of re-entrant mesophases have also been found in binary mixtures of non-polar liquid-crystalline compounds. 

V. Vill. LIQCRYST 2.1, Database of Liquid Crystalline Compounds for Personal Computers, LCI Publisher GmbH, Hamburg (1996). 

Many biological systems exhibit [he properties of liquid crystals. Considerable concentrations of liquid crystalline compounds have been lound in many parts of the hody, often as sterol or lipid derivatives A liquid crystal... 

It is evident that these structural guidelines for the second type of polymer are closely akin to those that define mesogenic segments in simple liquid-crystalline compounds. 

Miyake I, Takanishi Y, Rao NVS, Kr M, Ishikawa K, Takezoe H (2005) Novel chiral filament in an achiral W-shaped liquid crystalline compound. J Mater Chem 15 4688 1694... 

As the name implies, liquid-crystalline materials combine the properties of a crystal with those of a liquid in a very special way and are therefore of interest for display and data storage technology. Liquid-crystalline compounds usually consist of rod- or disc-shaped organic molecules which preferentially adopt a mutually parallel orientation [33]. A change of molecular orientation caused by application of an electrical potential transforms the optical properties and can be utilised for display applications. 

Over a century ago, Professor Otto Lehmann of the University of Karlsruhe - who is acknowledged as the pioneer of liquid crystal technology - disagreed with the scientific establishment about the existence of the liquid crystalline state of aggregation. Lehmann turned to Merck. He asked the company to supply him (and others) with liquid crystalline compounds so that he could clarify what no amount of theoretical debate could resolve. This was Merck s first foray into the LC business - although there was no actual business at this stage. Nevertheless, it was already well known that Merck supplied products of the highest purity, which allowed results to be replicated accurately. 

Title Liquid Crystalline Compound, Liquid Crystalline Composition, and Retardation Film... 

The log, lath-like molecular structure of most liquid crystalline compounds makes the cross-coupling protocol very important in syntheses [178,179]. The method based on arylboronic acids simplifies the procedure for liquid crystal materials of more complex substitution patterns [64,180,181] (Scheme 32). The synthesis of arylboronic acids via ortho-metalation of fiuoroarenes and the successive cross-coupling reaction readily extended the aryl units. The Pd/C-cat-alyzed reaction was also reported as an economical alternative [64]. Several liquid crystals having a biaryl unit are now an industrial process of Merck in Germany (ca. 3 tons/year) [182]. 

The molecular design of these materials is based on a central focal point to which mesogenic units are linked, so that restricted moleciflar topologies and limited molecular flexibility are induced [57]. They represent a class of materials intermediate between low molecular weight liquid-crystalline compounds and dendritic systems, and can be described as supermolec-ular entities or giant molecular systems made up of covalently attached... 

In a search for new isoxazole-based liquid crystalline compounds, a 22-member library of 3,5-diaryl isoxazoles 628 was prepared by parallel synthesis on solid phase (Rink resin) through 1,3-dipolar cycloaddition of supported phenylacetylene units with suitable aryl nitrile oxides generated in situ from hydroxyiminoyl chlorides. Cleavage from the resin under acidic conditions allowed the generation of the cyano moiety <2004TL2277>. 

Liquid crystalline compounds are remarkable because of their ability to show spontaneous anisotropy and readily induced orientation in the liquid crystalline state. When polymers are processed in the liquid crystalline state, this anisotropy may be maintained in the solid state and can readily lead to the formation of materials of great strength in the direction of orientation. A particularly important example of the use of this property for polymers is in the formation of fibers from aromatic polyamides which are spun from shear oriented liquid crystalline solutions Solutions of poly(benzyl glutamate) also show characteristics of liquid crystalline mesophases, and both of these types of polymers are examples of the lyotropic solution behaviour of rigid rod polymers which was predicted by Flory... 

In addition to characterization of the mesophase by microscopy and X-ray diffraction, the most common technique for studying liquid crystalline compounds is by thermal... 

Miyazawa, K., Yulil, D. S., Howard, J. A. K. and de Meijere, A. (2000) Cyclopropyl building blocks fororganic synthesis, 60. Synthesis and properties of optically activedispiro[2.0.2.1 ]heptane derivatives as novel ferroelectric liquid crystalline compounds. Eur. J. Org. Chem., 2000, 4109-4117. 

ANOMALOUS DECOUPLING OF THE DC CONDUCTIVITY AND THE STRUCTURAL RELAXATION TIME IN THE ISOTROPIC PHASE OF A ROD-LIKE LIQUID CRYSTALLINE COMPOUND... 

Abstract Recently, the isotropic phase of rod-like liquid crystalline compounds is advised as an experimental model system for studying complex glassy dynamics. One of unique phenomena occuring close to the glass... 

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