- Nematic compounds
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Nematic compounds with a negative DC antisotropy, characterized by the formula I STR1 in which m=1 or 2, r is zero or 1 and m+r=1 or 2, and R1 and R2 are identical or different and are selected from alkyl and alkoxy groups each havin
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- The Properties of Liquid Crystal Materials Incorporating the -CH2O- Inter-ring Linkage
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To establish more securely the influence of the -CH2O- inter-ring linkage upon the properties of mesogens of both high and low dielectric anisotropy, a range of ethers with the following general structure has been prepared and their properties examined. The thermal and electro-optic properties of the compounds are discussed, and comparisons made where possible with analogous materials incorporating the -CH2CH2- linkage.
- Carr, N.,Gray, G. W.
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- The Synthesis and Liquid-Crystal Transition Temperatures of Some Fluoro-Substituted Benzonitriles
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Various laterally fluoro-substituted benzonitriles have been prepared containing a trans-4-(n-alkyl)cyclohexane ring linked to the 4-position of the benzonitriles either through a methyleneoxy (-CH2O-) or an ethylene (-CH2CH2-) bridge.The bridging group links the benzonitrile and cyclohexane rings either directly or through an additional 1,4-bonded cyclohexane or benzene ring.The synthesis and liquid-crystal transition temperatures of these new compounds are described.In several cases the nematic-isotropic transition temperatures of F-substituted benzonitriles are found to be higher than those of the non-laterally substituted analogues.
- Kelly, Stephen M.,Schad, Hanspeter
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p. 1444 - 1452
(2007/10/02)
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- SYNTHESIS AND SOME PHYSICAL PROPERTIES OF 1-CYCLOHEXYL-2-(4 double prime -HALOBIPHENYL-4 prime -yl)ETHANES.
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A series of 1-(trans-4 prime -n-alkylcyclohexyl)-2-(4 double prime -halobiphenyl-4 prime -yl)ethanes, which show nematic phases, was prepared. Their transition temperatures, enthalpies and entropies were measured. Their bulk viscosities, birefringences and dielectric constants were determined by extrapolation. The bulk viscosity as a function of the third power of the van der Waals radius of the halogeno group, the birefringence as a function of the van der Waals radius of the halogeno group, and the dielectric constants as a function of the dipole moment of the halogeno group are discussed for the 1-(trans-4 prime -n-propylcyclohexyl)-2-(4 double prime -halobiphenyl-4 prime -yl)ethanes.
- Takatsu,Takeuchi,Sato
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p. 345 - 355
(2007/10/02)
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- 1-(TRANS-4 prime -N-ALKYLCYCLOHEXYL)-2-(4 double prime -CYANOPHENYL)ETHANES - A NEW SERIES OF STABLE NEMATOGENS OF POSITIVE DIELECTRIC ANISOTROPY.
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The synthesis and some important properties of the 1-(trans-4 prime -n-alkylcyclohexyl)-2-(4 double prime -cyanophenyl)ethanes - where n-alkyl equals C//1 to C//7 - are described.
- Carr,Gray,McDonnell
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