84219-03-4Relevant articles and documents
Liquid crystalline compounds based on 1,4-disubstituted but-1-YNE
Dabrowski,Dziaduszek,Szczucinski,Parka
, p. 201 - 215 (2007/10/02)
Liquid crystalline compounds containing the -CH2CH2-C ≡ C- inter-ring linkage between cyclohexane and benzene rings belonging to four homologous series have been prepared. Their mesogenic, viscous, dielectric, optical, and dielectrooptical properties were investigated and compared with the properties of analogous compounds with the -CH2CH2- or -C ≡ C- bridge groups. The mesogenic and physical properties of the compounds with the -CH2CH2-C ≡ C- linkage group are intermediate between properties of the compounds with -C ≡ C- and the properties of the compounds with -CH2CH2- group, except that their clearing points are lower and viscosity is higher.
The Effect of Lateral Fluorosubstitution on the Liquid Crystalline Properties of some 4-n-Alkyl-, 4-n-Alkoxy- and Related 4-Substituted-4'-cyanobiphenyls
Fearon, J. E.,Gray, G. W.,Ifill, A. D.,Toyne, K. J.
, p. 89 - 104 (2007/10/02)
The syntheses of several 4-n-alkyl-, 4--, 4-- and 4-n-alkoxy-4'-cyano-2'-fluorobiphenyls and -4'-cyano-2-fluorobiphenyls are presented and the transition temperatures for these compounds are reported and discussed.In the alkylkcyanobiphenyls, a 2-fluoro-substituent causes a greater depression of TN-I (35-39 deg C) than a 2'-fluoro-substituent (13-18 deg C) and a similar situation arises for the cyclohexylethyl compounds.The fluoro-substituted alkoxy-compounds also give two series with depressions of TN-I of 34-41 deg C for the 2-fluoro- and 15-20 deg C for the 2'-fluoro-compounds.In non-cyano systems, 2- and 2'-fluoro-substituents in biphenyl derivatives give similar depressions in TN-I, which are larger than found in cyano systems, and the different depressions for the fluoro-substituted cyano compounds are thought to arise because of the effect of the fluorine on the anti-parallel correlations of the parent systems.The effects on smectic and nematic thermal stabilities are qualitatively similar, but are usually greater for smectic transitions.A comparison is made between 4-trans-cyclohexylethyl and 4-phenylethyl units in the 4'-cyano- and 4'-bromo-2'-fluorobiphenyls.
SYNTHESIS AND SOME PHYSICAL PROPERTIES OF 1-CYCLOHEXYL-2-(4 double prime -HALOBIPHENYL-4 prime -yl)ETHANES.
Takatsu,Takeuchi,Sato
, p. 345 - 355 (2007/10/02)
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.
1-(TRANS-4 prime -N-ALKYLCYCLOHEXYL)-2-(4 double prime -CYANOPHENYL)ETHANES - A NEW SERIES OF STABLE NEMATOGENS OF POSITIVE DIELECTRIC ANISOTROPY.
Carr,Gray,McDonnell
, p. 13 - 28 (2007/10/02)
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.
