- Synthesis, Fourier transform infrared, 1D and 2D NMR spectral studies on the conformation of two new cholesteryl 4-alkoxyphenyl-4′ benzoates
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Two new cholesteryl 4-alkoxyphenyl-4′-benzoates (CnH 2n+1OC6H4C6H4COOCh), where Ch represents cholesteryl moiety and n = 10 and 16) have been synthesized and their molecular orientation at ambient temperature were studied. The structure determination on these compounds was performed in solid state by infrared spectroscopy based on vibrational analysis wherein the cholesteryl-phenyl and phenyl-aliphatic carbon linkages were concluded. Their molecular structures were further ascertained through the 1H and 13C NMR spectra along with two-dimensional COSY, NOESY, ROESY, 1H-13C HMQC and HMBC. The long-range connectivity as concluded from the NOESY, ROESY and HMBC spectra together with the related data led to a postulation that the title compounds in the liquid state exist in the conformation whereby the cholesteryl moiety was not lying along the entire molecular long axis. The cholesteryl fragment was presumed to be bent at the ester linkage of O=C-O and the phenyl rings located between cholesteryl and alkoxy chain group are not coplanar.
- Yeap, Guan-Yeow,Ha, Sie-Tiong,Ito, Masato M.,Boey, Peng-Lim,Mahmood, Wan Ahmad Kamil
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- Investigation of thermodynamic properties of 4-decyloxybiphenyl-4′-carboxylic acid liquid crystal and preparation of polymer dispersed liquid crystal composite
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In this study, firstly, retention behavior of solvents on the liquid crystalline material 4-decyloxybiphenyl-4′-carboxylic acid (DBCA) has been studied by inverse gas chromatography (IGC) technique. Liquid crystal (LC) selectivity was investigated using t
- ?ztürk, Emine,Ocak, Hale,Cakar, Fatih,Karanl?k, Gürkan,Cankurtaran, ?zlem,Bilgin-Eran, Belkis
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- Anisotropic and magnetic properties in non-metal and non-radical organic aggregates of tri-substituted phenyl derivatives
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A new series of tri-substituted phenyl derivatives containing an aromatic imine unit and biphenyl ester possessing various numbers of carbon atoms at the terminal alkoxy chain, OCnH2n+1 (n = 7-12), along with a lateral o-ethoxy substituent have been successfully prepared and characterised by CHN microanalysis along with spectroscopic techniques (FTIR, 1H- and 13C-NMR). The texture observation under polarized light revealed that all the soft condensed materials exhibited an enantiotropic nematic (N) phase. The current studies have shown that the mesomorphic behaviour is greatly influenced by the length of the alkoxy chains wherein the thermal stability of a tri-substituted phenyl derivative will decrease if the terminal alkoxy chain is increased from n = 7 to 12. For the first time, these materials which do not possess any magnetic species in their structure, demonstrate magnetic interaction through naked eye observation as well as quantitative measurement using a SQUID magnetometer.
- Tun Nur Iskandar, Nur Amanina Juniasari,Guan-Yeow, Yeap,Maeta, Nobuyuki,Ito, Masato M.,Nakamura, Yoshiyuki,Gas, Katarzyna,Sawicki, Maciej
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p. 210 - 217
(2019/12/25)
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- A modulated helical nanofilament phase
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A new liquid crystal phase, denoted modulated helical nanofilament (HNF(mod)), is formed from a very simple class of biphenyl carboxylates lacking the benzylidene aniline moieties typically found in HNF mesogens. The HNF(mod) phase represents a novel kind of nanoparticle possessing stacked aromatic rings, with potential applications in organic electronics. Copyright
- Tsai, Ethan,Richardson, Jacqueline M.,Korblova, Eva,Nakata, Michi,Chen, Dong,Shen, Yongqiang,Shao, Renfan,Clark, Noel A.,Walba, David M.
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p. 5254 - 5257
(2013/06/05)
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- Photo and electrically switchable B7 mesophase exhibiting asymmetric bent-core liquid crystals
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The first bent-core liquid crystal materials with a photo-active azo linkage exhibiting the B7 mesophase are reported. The lower homologues of the bent-core compounds display the B1 phase and higher homologues show the B7 mesophase. The mesomorphic properties were characterized using polarized optical microscopy, differential scanning calorimetry and X-ray diffraction. The B7 phase of these materials establishes ferroelectric switching characteristics with anticlinic organization (SmCAPF) of the molecules in the layers. The bent-core molecules with an azo linkage are important for photoisomerization studies, which indicate trans to cis isomerization at 30 s, whereas the reverse processes take place over 40 s in chloroform.
- Srinivasan, Murugesan Vijay,Kannan, Palaninathan,Roy, Arun
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p. 1584 - 1590
(2013/06/04)
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- Liquid crystal compounds, mixtures and devices
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An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
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Page column 21
(2008/06/13)
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- Liquid crystal compounds, mixtures and devices
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An electoclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
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- Mesomorphic trigonal bipyramidal iron(0) isocyanide complexes
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The synthesis, characterization and mesomorphic properties of three series of isocyanides and their trigonal bipyramidal iron(0) complexes [Fe(CO)4(CNR)] (R= C6H4O(O)CC6H4C6H4OC(n)H2(n)+1, C6H4C(O)OC6H4C6H4OC(n)H2(n)+1, C6H4C6H4O(O)CC6H4OC(n)H2(n)+1, n = 6, 8, 10, 12) are described. The free isocyanides exhibit nematic and/or smectic A phases for shorter chains (n = 6, 8) and only smectic A phases for longer chains, except the isocyanides CNC6H4O(O)CC6H4C6H4OC(n)H2(n)+1 which melt with extensive decomposition and do not produce mesophases. Their coordination to give the iron complexes [Fe(CO)4(CNR)] produces a slight decrease of their transition temperatures. The iron isocyanide complexes prepared show only a smectic C phase. The relationship between the molecular structure of the complexes and their thermal behaviour is discussed.
- Coco, Silverio,Espinet, Pablo,Marcos, Eva
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p. 1297 - 1302
(2007/10/03)
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- Carboxylate compounds, liquid crystal materials liquid crystal compositions and liquid crystal elements
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There is provided a carboxylic acid compound represented by the following formulae (I) to (IV): STR1 a liquid crystal material consisting of the carboxylic acid ester compound, a liquid crystal composition comprising the carboxylic acid ester compound, and a liquid crystal element using the carboxylic acid ester compound. There can be obtained advantages such as low operating temperature, high speed switching, very small electric power consumption, and high-stable contrast.
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- Synthesis and characterization of ferroelectric and antiferroelectric liquid crystals derived from (2S)-2-(6-hydroxy-2-naphthyl)propionic acid
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A new series of chiral materials, hexyl(2s)-2-(6-(-4-(4′-alkoxyphenyl)benzoyloxy)-2′-naphthyl) propionates (HmPBNP; m = 6-18) had been prepared and their liquid crystalline properties were investigated as a function of alkyl chain length. These chiral materials exhibited novel ferroelectric Sc* and antiferroelectric ScA* phases and a propensity to the formation of the ScA* phase was found at longer alkyl chain lengths (m = 10, 12-18). An odd-even effect of the threshold voltage as a function of alkyl chain length for compounds HmPBNP (m = 12-16) possessing antiferroelectricity was observed. Spontaneous polarization and transverse dipole moment were also measured and are discussed in terms of the elongated alkyl chain length.
- Wu,Chen,Chen,Wang,Shy,Hsiue
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- Liquid crystal material, liquid crystal composition and liquid crystal element
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Disclosed is a liquid crystal material represented by the following formula [I]: wherein R is an alkyl or polyfluoroalkyl group; X is a group such as --COO--, or a single bond; n is 0 or 1; A1, A2 and A3 are each a cyclic group such as tetralin, and at least one of them has an optically active group; Y1 and Y2 are each a group such as --COO--; Z is a group such as --O--, or a single bond; and R* is an optically active group. Also disclosed are a liquid crystal composition comprising the liquid crystal material represented by the above formula, and a liquid crystal element in which the liquid crystal material is used. The liquid crystal material of the invention shows excellent liquid crystal characteristics because it has at least two optically active groups.
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- Optically active alcohol and derivatives thereof, liquid crystal composition containing same and liquid crystal device
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Optically active compounds of general formulae STR1 wherein A is O or S, R1 is a hydrogen atom, an alkyl group having 1-22 carbon atoms, a hydroxy containing alkyl group, para-alkyl substituted phenyl, para-alkyl substituted biphenyl, hydroxyphenyl, hydroxybiphenyl or tosyl; R2 is an alkyl group having 2-8 carbon atoms; m is an integer of 0-5, n is 0 or 1, where when m=0, n is not 1; p is 0 or 1; q is 0 or 1; D and E are independently H or a halogen atom; R3 is a linear alkyl group having 1 to 22 carbon atoms; and * and ** are asymmetric centers.
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- Liquid crystal compounds and intermediates thereof
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A liquid crystal compound of the formula: STR1 wherein m and n are independently integers of 1 to 22; k and l are independently integers of 1 to 2; and C* is an asymmetric carbon atom, is chemically stable and can be applied to liquid crystal display devices operable at room temperature.
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- Optically active compound having XI-valerolactone ring and liquid crystal composition comprising same
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An optically active compound having a δ-valerolactone ring which is a ferroelectric liquid crystal and is represented by the following general formula (I): STR1 wherein m is an integer of from 1 to 8, Z is a group represented by the following formula: STR2 in which each of l and k is a number of 1 or 2 and l and k satisfy the requirement of 2≤(l+k)≤3, X stands for a direct bond, STR3 Y stands for STR4 and A1 and A2 independently stand for --H, --F or --Cl, STR5 R stands for STR6 in which n is an integer of from 1 to 18, and * indicates the asymmetric carbon atom.
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- Thermal and Ferroelectric Properties of Novel Ferroelectric Liquid Crystals Containing α-Methylcinnamoyl Moiety in the Core Structure
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Six homologous series of novel ferroelectric liquid crystals containing α-methylcinnamoyl moiety in the core structure: have been synthesized and their thermal and ferroelectric properties have been investigated.The mesomorphic transition temperatures and the spontaneous polarization for the homologous series (IA, IB, IIA, IIB, IIIA and IIIB) depend on the core structure, the chiral group, and the terminal alkoxyl chain length.These homologous series show the chiral smectic C phase over wide temperature ranges including room temperature and the values of their maximum spontaneous polarization are in the range of 30 to 800 μC m-2.The thermal stability of the mesophase and the magnitude of the spontaneous polarization have been discussed from the view point of the molecular structure and the local molecular interactions.
- Nakauchi, Jun,Kageyama, Yoshitaka
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p. 2573 - 2578
(2007/10/02)
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- Alpha-methylcinnamic acid ester derivative and liquid crystal composition
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Disclosed is an α-methylcinnamic acid ester derivative represented by the formula: STR1 wherein n is an integer of from 5 to 18, R1 represents an optically active group of the formula STR2 in which m is an integer of from 1 to 5 and *C represen
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