96515-25-2Relevant academic research and scientific papers
Liquid crystal composition and liquid crystal display device
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Page/Page column 27; 28, (2018/02/28)
A liquid crystal composition satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to ultraviolet light and heat, or has a suitable balance regarding at least two of the characteristics. The composition contains a specific compound having high stability to ultraviolet light as a first component, and a liquid crystal display device includes the composition. The composition may contain a specific compound having large negative dielectric anisotropy as a second component, a specific compound having high maximum temperature or small viscosity as a third component, and a specific compound having a polymerizable group as an additive component.
Synthesis and Liquid Crystal Behaviour of Further 4,4"-Disubstituted 2'-Fluoro-1,1':4',1"-Terphenyls
Chan, L. K. M.,Gray, G. W.,Lacey, D.,Toyne, K. J.
, p. 209 - 240 (2007/10/02)
Further to earlier work on the liquid crystal properties of fluoro-1,1':4',1"-terphenyls we have now extended this series to include terminally fluoro- and cyano-substituted 2'-fluoro-1,1':4',1"-terphenyls, chiral 2'-fluoro-1,1':4',1"-terphenyls, and esters derived from 2'-fluoro-1,1':4',1"-terphenyls and incorporating the alkylcyclobutyl group.The preparations and transition temperatures for these series of compounds are presented and their transition temperatures and mesophase types are discussed.An interesting result from this work was the appearence of an S*C phase for one chiral homologue and of SC phases for the esters incorporating the alkylcyclobutyl group.The SC formation is attributed to the presence of the fluoro-substituent.Keywords: terphenyls, fluoroterphenyls, smectic C phases, cyclobutyl esters.
Compounds containing a fluorobiphenylyl group
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, (2008/06/13)
Novel terphenyls having a relatively high clearing point and which are suitable for use in liquid crystal materials or in the preparation of compounds for use in such material are characterised by a formula: STR1 wherein: R1 is selected from H, alkyl, alkoxy, alkylcarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy; R2 is selected from H, alkyl, alkoxy; X1 is selected from H and fluorine; X2 is selected from H and fluorine; and STR2 is selected from STR3 and STR4 provided that one of X1 and X2 is fluroine. Compounds wherein STR5 is STR6 or STR7 are generally useful as liquid crystal compounds.
Synthesis and Evaluation of Some 4,4''-Disubstituted Lateral Fluoro-1,1':4',1''-terphenyls
Chan, L. K. M.,Gray, G. W.,Lacey, D.
, p. 185 - 204 (2007/10/02)
A number of laterally fluorinated 4,4''-di-n-alkyl-, 4,4''-di-n-alkoxy- and 4-n-alkyl-4''-n-alkoxy-1,1':4',1''-terphenyls of structure (I) have been synthesised, with the lateral fluoro-substituent in the central benzene ring. The nematic and smectic thermal stabilities for all three series of compounds, have been examined.A typical example is (I), X = n-C5H11, Y = n-C3H7, C-N 50 deg C and N-I 140.6 deg C.For the 4,4''-di-n-alkyl-1,1':4',1''-terphenyls, the position of the lateral fluoro-substituent with respect to the longest n-alkyl chain is found to be important in determining the smectic behaviour of this class of compound.By using a combination of optical microscopy, X-ray diffraction and miscibility studies, the complex smectic behaviour of the higher homologues of this series has also been investigated.A comparison of the liquid crystal behaviour of the laterally fluorinated terphenyls of structure (I) with their non-fluorinated analogues is also given.A selected number of these compounds, have been further examined to assess their usefulness as high TN-I additives for multiplexed mixtures used in electro-optic display devices.
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.
