Two series of novel tolane-type liquid crystals (LCs) comprising of hydrogen-bonded organic acids were synthesized. The formation of dimerized H-bond LCs was confirmed by IR spectroscopy, and mesomorphic properties ...Two series of novel tolane-type liquid crystals (LCs) comprising of hydrogen-bonded organic acids were synthesized. The formation of dimerized H-bond LCs was confirmed by IR spectroscopy, and mesomorphic properties of the LCs were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). It was found that the end groups of the liquid crystals as well as the unsaturated rigid core had effect on the mesomorphic properties.展开更多
A series of symmetrical azine-type liquid crystals were synthesized. The characteristic of these liquid crystals is that they had high clearing point (~320℃) and broad thermal range of nematic phase (~154℃). I...A series of symmetrical azine-type liquid crystals were synthesized. The characteristic of these liquid crystals is that they had high clearing point (~320℃) and broad thermal range of nematic phase (~154℃). It was also found that the end groups of the liquid crystals had effect on the mesomorphic properties.展开更多
A new series of Schiff base esters, 4-(dimethylamino)benzylidene-4'-alkanoyloxyanilines containing even number of carbons at the end group of the molecules (Cn-1H2n-1COO, n = 6, 8, 10, 12, 14, 16, 18) were synthe...A new series of Schiff base esters, 4-(dimethylamino)benzylidene-4'-alkanoyloxyanilines containing even number of carbons at the end group of the molecules (Cn-1H2n-1COO, n = 6, 8, 10, 12, 14, 16, 18) were synthesized. The present compounds were monotropic liquid crystals. It was also found that the end groups of the molecules had effect on the mesomorphic properties. C 2009 Sie Tiong Ha. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
A homologous series of n-butyl-4-[4-((4-n-alkoxyl-tetrafluorophenyl)ethynyl)benzyloxy] benzoates have been synthesized. Their phase transition temperatures have also measured by polarizing textural observation and con...A homologous series of n-butyl-4-[4-((4-n-alkoxyl-tetrafluorophenyl)ethynyl)benzyloxy] benzoates have been synthesized. Their phase transition temperatures have also measured by polarizing textural observation and confirmed by DSC.展开更多
This article describes the preparation and liquid crystalline properties of a new homologous series of 4-(4-bromopropyloxy)-4'- (4-alkyloxybenzylidene)anilines in which the phenyl ring is armed by a bromopropylox...This article describes the preparation and liquid crystalline properties of a new homologous series of 4-(4-bromopropyloxy)-4'- (4-alkyloxybenzylidene)anilines in which the phenyl ring is armed by a bromopropyloxy chain.The thermal behavior and mesomorphic properties of the synthesized compounds were studied with particular attention given to the correlation between their phase transition temperatures and anisotropic change influenced by molecular structure.All the members displayed enantiotropic smectic phase except for the homologue with the longest alkyloxy chain(R = C_(18)H_(37)),exhibiting only monotropic characteristic. The presence of bromine atom from the propyloxy side chain is found to be capable of altering and influencing the mesomorphic properties.展开更多
Four series of trifluorobenzoate liquid crystals have been synthesized. Their phase transition temperatures have been also measured by texture observation in a polarizing microscope and confirmed by DSC. The influence...Four series of trifluorobenzoate liquid crystals have been synthesized. Their phase transition temperatures have been also measured by texture observation in a polarizing microscope and confirmed by DSC. The influence of the lateral fluoro-substitution and triple bond has been also discussed.展开更多
Abstract Four homologue series of 4-cyano- and 4-nitro-substituted benzoate-tolanes were synthesized and characterized by IR, NMR, MS spectra and elemental analysis. Their phase transition behaviors were investigated ...Abstract Four homologue series of 4-cyano- and 4-nitro-substituted benzoate-tolanes were synthesized and characterized by IR, NMR, MS spectra and elemental analysis. Their phase transition behaviors were investigated by DSC and polarized optical microscope. The effects on the mesomorphic properties of different positions of the perfluorophenyl in the molecular core unit, the terminal cyano-substituted systems and the terminal nitro-substituted ones were discussed.展开更多
基金supported by National Natural Science foundation(No.20674005)Program of National High Technology 863 program of China(No.2006AA03Z108)+1 种基金National Key Technology Program(No.2007BAE31B00)Key Program for Panel Display of 863 program of China(No.2008AA03A318)
文摘Two series of novel tolane-type liquid crystals (LCs) comprising of hydrogen-bonded organic acids were synthesized. The formation of dimerized H-bond LCs was confirmed by IR spectroscopy, and mesomorphic properties of the LCs were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). It was found that the end groups of the liquid crystals as well as the unsaturated rigid core had effect on the mesomorphic properties.
文摘A series of symmetrical azine-type liquid crystals were synthesized. The characteristic of these liquid crystals is that they had high clearing point (~320℃) and broad thermal range of nematic phase (~154℃). It was also found that the end groups of the liquid crystals had effect on the mesomorphic properties.
基金Universiti Tunku Abdul Rahman(UTAR) for the research facilities andfinancial support through UTAR Vote No.6202/O05Universiti Sains Malaysia for the use of its research facilities.
文摘A new series of Schiff base esters, 4-(dimethylamino)benzylidene-4'-alkanoyloxyanilines containing even number of carbons at the end group of the molecules (Cn-1H2n-1COO, n = 6, 8, 10, 12, 14, 16, 18) were synthesized. The present compounds were monotropic liquid crystals. It was also found that the end groups of the molecules had effect on the mesomorphic properties. C 2009 Sie Tiong Ha. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Project supported by the Advanced Materials R & D Program of China and the National Natural Science Foundation of China and Natural Science Foundation of Shanghai Municipality.
文摘A homologous series of n-butyl-4-[4-((4-n-alkoxyl-tetrafluorophenyl)ethynyl)benzyloxy] benzoates have been synthesized. Their phase transition temperatures have also measured by polarizing textural observation and confirmed by DSC.
基金Universiti Sains Malaysia for USM RU(No.1001/PKIMIA/811159) and the research facilities
文摘This article describes the preparation and liquid crystalline properties of a new homologous series of 4-(4-bromopropyloxy)-4'- (4-alkyloxybenzylidene)anilines in which the phenyl ring is armed by a bromopropyloxy chain.The thermal behavior and mesomorphic properties of the synthesized compounds were studied with particular attention given to the correlation between their phase transition temperatures and anisotropic change influenced by molecular structure.All the members displayed enantiotropic smectic phase except for the homologue with the longest alkyloxy chain(R = C_(18)H_(37)),exhibiting only monotropic characteristic. The presence of bromine atom from the propyloxy side chain is found to be capable of altering and influencing the mesomorphic properties.
基金Projected (No.59573017) supported by the National Natural Science Foundation of China.
文摘Four series of trifluorobenzoate liquid crystals have been synthesized. Their phase transition temperatures have been also measured by texture observation in a polarizing microscope and confirmed by DSC. The influence of the lateral fluoro-substitution and triple bond has been also discussed.
基金Project supported by the National Natural Science Foundation of China (No. 29974038)
文摘Abstract Four homologue series of 4-cyano- and 4-nitro-substituted benzoate-tolanes were synthesized and characterized by IR, NMR, MS spectra and elemental analysis. Their phase transition behaviors were investigated by DSC and polarized optical microscope. The effects on the mesomorphic properties of different positions of the perfluorophenyl in the molecular core unit, the terminal cyano-substituted systems and the terminal nitro-substituted ones were discussed.