82380-25-4Relevant academic research and scientific papers
The Synthesis and Liquid Crystal Behavior of p-Benzotrifluoride Compounds II
Liang, J. C.,Chen, L.
, p. 253 - 258 (2007/10/02)
Four compounds with the general structure R-X-Y-CH2-CH2-Ph-CF3 were synthesized, where X is a 1,4-disubstituted trans-cyclohexyl ring, Y is a phenyl ring, and R is a n-alkyl group.The synthetic procedure is discussed and the structural assignments were confirmed by NMR spectroscopy.The liquid crystal behavior of these compounds was evaluated by DSC and polarizing microscopy.They might be used in fast switching liquid crystal mixtures.
The Synthesis and Liquid-Crystal Transition Temperatures of Some Fluoro-Substituted Benzonitriles
Kelly, Stephen M.,Schad, Hanspeter
, p. 1444 - 1452 (2007/10/02)
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.
KETONES-NEMATOGENS WITH MODERATE NEGATIVE DIELECTRIC ANISOTROPY AND HIGH CLEARING POINTS.
Osman,Huynh-Ba
, p. 141 - 152 (2007/10/02)
Anisotropic ketones whose rigid cores contain phenyl and cyclohexyl units were synthesized. The carbonyl group was incorporated either in the terminal substituents or in the link between the core units. The mesomorphic behavior of these ketones is described and correlated with their chemical structure. The 1-(4-alkanoylphenyl)-4-trans-alkylcyclohexanes as well as the 1-(4-alkanoylphenyl)-4-trans-alkanoylcyclohexanes show nematic phases. In contrast to laterally substituted compounds, these ketones have clearing points which are higher than those of the corresponding hydrocarbons. Another advantage of these nematogens is the ease of synthesis.
Aliphatic Liquid Crystals with Positive Dielectric Anisotropy
Osman, Maged A.,Huynh-Ba, T.
, p. 959 - 963 (2007/10/02)
Cyanoethyl-substituted cyclohexyl cyclohexanoates, bi(cyclohexanes) and phenyl cyclohexanes were synthesized.Their mesomorphic behaviour is compared to that of the corresponding cyano derivatives. (Cyanoethyl)cyclohexyl cyclohexanoates show mesomorphic properties in contrast to the corresponding cyano derivatives.Separation of the cyano substituent from the rigid core of an anisotropic aliphatic compound by methylene groups enhances the thermodynamic stability of its mesophase.In aromatic compounds, the cyanoethyl group leads to lower clearing points.These phenomena are attributed to the influence of steric effects on the packing density and to the dependence of the clearing point on molecular association.
