- 2-Aryl benzazole derived new class of anti-tubercular compounds: Endowed to eradicate mycobacterium tuberculosis in replicating and non-replicating forms
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The high mortality rate and the increasing prevalence of Mtb resistance are the major concerns for the Tuberculosis (TB) treatment in this century. To counteract the prevalence of Mtb resistance, we have synthesized 2-aryl benzazole based dual targeted molecules. Compound 9m and 9n were found to be equally active against replicating and non-replicating form of Mtb (MIC(MABA) 1.98 and 1.66 μg/ml; MIC(LORA) 2.06 and 1.59 μg/ml respectively). They arrested the cell division (replicating Mtb) by inhibiting the GTPase activity of FtsZ with IC50 values 45 and 64 μM respectively. They were also capable of kill Mtb in non-replicating form by inhibiting the biosynthesis of menaquinone which was substantiated by the MenG inhibition (IC50 = 11.62 and 7.49 μM respectively) followed by the Vit-K2 rescue study and ATP production assay.
- Datta, Dhrubajyoti,Debnath, Joy,Franzblau, Scott G.,Ghosh, Kalyan Sundar,Hari, Natarajan,Ma, Rui,Rana, Shiwani,Velappan, Anand Babu
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- Effect of the Functional Groups of Racemic Rodlike Schiff Base Mesogens on the Stabilization of Blue Phase in Binary Mixture Systems
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Four series of rodlike racemic Schiff base mesogens possessing different alkyl chains and two types of linkages, ester and alkynyl linkages, were synthesized and applied to induce cubic blue phases (BPs) in simple binary mixture systems. The mesophases of these Schiff base mesogens were confirmed by variable-temperature X-ray diffraction and the characteristic texture from polarized optical microscopy (POM). In general, when chiral additive S-(+)-2-octyl 4-(4-hexyloxybenzoyloxy)benzoate (S811; 20-40 wt %) is added into the rodlike racemic salicylaldimine-based mesogens, the cubic BPs could be observed and its temperature range is larger than 20 K. The widest temperature range of the cubic BP (35 K) can be observed in the blending mixture composed of rodlike racemic salicylaldimine-based mesogen OH-TIn possessing alkynyl linkage and 35-40 wt % S811. However, Schiff base mesogens possessing alkynyl linkage show a direct isotropic to chiral nematic transition when equal amount of chiral dopant is added. Notably, the termination temperature of BPs is very close to room temperature (ca. 35 °C) after 40.0 wt % S811 is added into the salicylaldimine-based mesogens possessing terminal alkyl chains and ester linkage. Interestingly, wide BPs (>30 K) can also be induced by adding chiral additive 1,4:3,6-dianhydro-2,5-bis[4-(n-hexyl-1-oxy)benzoic acid]sorbitol (ISO(6OBA)2) with a high helical twisting power into the racemic Schiff base mesogen possessing ester linkage. Cubic BPI and BPII can be confirmed by reflectance spectra and POM. The results of reflectance spectra indicate that the binary mixture composed of salicylaldimine-based mesogens and S811 easily exhibits a supercooling effect and induces BPI. However, only BPII can be observed in all binary mixtures containing Schiff base mesogens. On the basis of our experimental results and molecular modeling, we suppose that the values of biaxiality, polarizability, and the dipole moment of molecular geometry are the main factors that affect BP stabilization.
- Huang, Chiung-Cheng,Wu, Zong-Ye,Sie, Bing-Han,Chou, We-Hao,Huang, Yu-Chang,Yu, Mei-Ching,Chen, Bo-Hao,Hsu, I-Jui,Wu, Lai-Chin,Lee, Jey-Jau
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p. 12736 - 12754
(2018/05/14)
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- Synthesis and mesomorphic investigations of liquid crystalline compounds having a benzothiazole ring
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Two homologous series of calamitic liquid crystals containing a benzothiazole ring and two different linkages have been prepared, and their liquid crystalline properties are studied and compared with each other and those of similar structure. The mesogens with only the cinnamate linking group showed better thermal properties than those with an ester. Nematic and smectic phases were observed. All the compounds of both the series were characterized by elemental analysis, FT-IR, mass spectrometry, 1H-NMR, and 13C-NMR. Phase transition temperatures and the thermal parameters were obtained from differential scanning calorimetery (DSC). The textural observations were performed using hot-stage Polarizing Optical Microscopy (POM).
- Thaker,Chothani,Patel,Dhimmar,Solanki,Patel, Neeraj,Patel,Makawana
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- Synthesis and comparative study on phase transition behavior of triazole-cored liquid crystals armed with cholesterol and double or triple aromatic rings systems
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Two homologous series of optically active bent-shaped mesogens comprising a cholesterol unit as one of the side arms connected to a 1,2,3-triazole ring while the other arm of the triazole ring is connected to two- and three-ring aromatic systems with varying terminal chain lengths have been synthesized. The molecular structure, thermal and optical activities have been studied extensively in which the compounds from both series exhibit polymorphism ranging from chiral nematic (N*), chiral smectic A (SmA*), chiral smectic C (SmC*) and twist grain boundary (TGBC*) phases. A further comparison between the two series of target compounds has drawn a common remark of which the phase behavior is found to be dependent on the length of the terminal tail and number of aromatic rings in the mesogenic units.
- Yeap, Guan-Yeow,Balamurugan, Subramanian,Srinivasan, Murugesan Vijay,Kannan, Palaninathan
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supporting information
p. 1906 - 1911
(2013/10/08)
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- Synthesis, characterization and mesomorphic properties of new rod-like thiophene based liquid crystals
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Two new mesogenic homologous series of Schiff base esters, 2-[4-(4-n-Alkoxy benzoyloxy) benzylidenamino] 3-cyno thiophine (Series-A) and Schiff base cinnamates, 2-[4-(4-n-alkoxy cinnamoyloxy) benzylidenamino] 3-cyano thiophene (Series-B), comprising a thiophene moiety were synthesized. Structural elucidation was carried out using elemental analysis and spectroscopic techniques such as FT-IR, 1H-NMR and 13C-NMR, and mass spectrometry. The mesomorphic properties and thermal stabilities of the title compounds were studied by using differential scanning calorimetry and optical polarizing microscopy. All the derivatives are mesomorphic in nature showing the nematic phase, and the higher members of Series-A show a smectic C phase whereas Series-B exhibits only the nematic mesophase. The mesomorphic properties of the present series are compared with other structurally related compounds. Taylor and Francis Group, LLC.
- Thaker,Patel,Dhimmar,Solnki,Chothani,Patel,Patel,Makavana
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experimental part
p. 98 - 113
(2012/10/07)
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- NOVEL GLP-1 RECEPTOR STABILIZERS AND MODULATORS
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Compounds that bind the glucagon-like peptide 1 (GLP-1) receptor, methods of their synthesis, methods of their therapeutic and/or prophylactic use, and methods of their use in stabilizing GLP-1 receptor in vitro for crystallization of the GLP-1 receptor are provided. Certain compounds may have activity as modulators or potentiators with respect to glucagon receptor, GIP receptor, GLP-1 and GLP-2 receptors, and PTH receptor on their own or in the presence of receptor ligands such as GIP(1-42), PTH(1-34), Glucagon(1-29), GLP-2(1-33), GLP-1 (7-36), GLP-1 (9-36), oxyntomodulin and exendin variants.
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Page/Page column 80-81
(2013/02/28)
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- Electro-optical switching studies on 1,3-phenylene based banana shaped liquid crystals
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This work deals with the study of the thermotropic liquid crystalline properties of new asymmetric bent core liquid crystals. The thermotropic properties was analyzed by polarized optical microscopy, differential scanning calorimetric analysis and variable temperature X-ray diffraction measurements. Effect of equal terminal chain with asymmetric bent core system on mesomorphic behavior was examined. The shorter methyl chain compound 10a of exhibits B 1 mesophase and higher homologs (10b and 10c) shows antiferroelectric B2 mesophases, which was studied by electro-optical measurements.
- Balamurugan,Kannan,Yadupati,Roy
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experimental part
p. 118 - 124
(2011/10/03)
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- A new way to access chiral liquid crystals: Organocatalyst-mediated synthesis of chiral rod-like liquid crystals
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In this article, an asymmetric organocatalytic way to prepare chiral liquid crystals from non-chiral starting materials was described. By using L-proline as the organocatalyst, several new chiral rod-like liquid crystals that are elusive with traditional methods were prepared. In addition, a series of novel enone-containing rod-like liquid crystals were also obtained as side-products. Mesomorphic properties of all new compounds were studied by Polarized Optical Microscope and Differential Scanning Calorimetry. Copyright Taylor & Francis Group, LLC.
- Wang, Li,Liu, Xiao-Jun,Huang, Ping,Gong, Qing-Ping,Li, Yong-Hong,Wang, Bi-Qin,Zhao, Ke-Qing
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scheme or table
p. 53 - 59
(2012/07/14)
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- Liquid crystalline properties of 3-[4-(4′- alkoxybenzoyloxybenzylidene) amino]-1,2,4-triazines: Synthesis and characterization
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A new series of 3-[4-(4′-alkoxybenzoyloxybenzylidene)amino]-1,2,4- triazines, C3H2N3N=CHC6H 4OCOC6H4OCmH2m+1 where m=6, 7, 8, 9, 10, 11, 12, 14, and 16 have been synthesized. These compounds have been characterized by elemental analyses, FT-IR, UV-visible, 1H, and 13C NMR spectroscopy. Mesomorphic properties of these compounds were studied by differential scanning calorimetry and polarizing microscopy. The mesomorphic nature of these compounds is dependent on the alkoxy chain length. The compounds (m=6, 7) do not exhibit mesomorphism while the compounds (m=8, 9, 11, 12, 14) show a monotropic nematic mesophase in cooling cycle. The 3-[4-(4′-decyloxybenzoyloxybenzylidene)amino]-1,2,4-triazine displays an enantiotropic nematic mesophase and the hexadecyloxy compound exhibits the smectic A mesophase. Copyright Taylor & Francis Group, LLC.
- Singh, Bachcha,Pandey, Ashwini,Singh, Sachin Kumar
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experimental part
p. 127 - 137
(2010/09/05)
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- Liquid crystalline properties of unsymmetrical N-(o-hydroxybenzylidene)- N′-(4-n-alkoxybenzoyloxybenzylidene)azines: Synthesis and characterization
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A new series of mesogenic unsymmetrical azines, N-(o-hydroxybenzylidene)- N′-(4-n-alkoxybenzoyloxybenzylidene)azines, HOC6H 4CH=N-N=CHC6H4OCOC6H4O CmH2m+1 (m=7, 8, 9, 10, 11, 12, 14, and 16) have been prepared. They have been characterized by elemental analyses, FT-IR, UV-visible, 1H, and 13C NMR (Nuclear Magnetic Resonance) spectra. The mesomorphic properties of these compounds were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The azines m=7, 10, and 14 exhibit features of enantiotropic nematic (N) mesophase whereas azines m=8, 11 exhibit features of a monotropic nematic phase. The azines m=9, 12, and 16 do not exhibit mesogenic nature. Copyright Taylor & Francis Group, LLC.
- Singh, Bachcha,Pandey, Ashwini
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experimental part
p. 148 - 158
(2010/09/05)
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- Synthesis and characterization of liquid crystalline materials incorporating the novel 4-amino-1,2,4-triazole and isonicotinic acid hydrazide moiety
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We report the synthesis and evaluation of thermal behavior of two new mesogenic homologous series of liquid crystalline compound containg 1,2,4-triazole and isonicotinic acid ring at the terminus of the molecule viz. 4-[(4H-1,2,4-triazol-4-ylimino) methyl] phenyl 4-alkoxybenzoate and 4-(2-isonicotinoylcarbonohydrazonoyl) phenyl 4-alkoxybenzoate. Both series have been characterized by elemental analysis, FT-IR, mass spectrometry, 1H-NMR, and 13C-NMR. Phase transition temperatures and the thermal parameters were obtained from differential scanning calorimetry (DSC). The texture observation was performed under polarizing optical microscopy (PMO) attached with Mettler hot stage. All the derivatives are mesomorphic in nature showing nematic phase and the higher member of both series shows smectic phase. The use of isonicotinic acid and triazole as a terminal group has a very dramatic effect on the melting and clearing points. The mesomorphic behavior has been analyzed in terms of structural property relationship.
- Thaker,Patel, Pranay
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- Synthesis of symmetric liquid crystal dimers based on 1,2-bis{-[-(4- alkoxybenzoyloxy)benzylidene]amino)phenoxy}ethane and investigation of phase behaviour by varying alkoxy terminal chain length
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With the objective to study the effect of alkoxy terminal chain length on mesomorphic properties of liquid crystals, We have synthesized ester and Schiff base dimers from diamine derivative containing 1,2-dioxyethylene as short spacer with aldehyde deriva
- Lee, Chang Sin,Kim, Tae Hyeong,Ramaraj,Ryu, Seok Gn,Song, Hyun Hoon,Lee, Soo-Min,Yoon, Kuk Ro
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experimental part
p. 117 - 129
(2010/03/03)
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- Synthesis, characterization, and mesomorphic properties of new liquid-crystalline compounds involving ester-azomethine central linkages, lateral substitution, and a thiazole ring
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In continuation with our work on liquid crystals with unconventional molecular structures, two homologous series that have 1,4-disubstitution and 1,3,4-trisubstitution in the central phenyl ring, such as 2[(4-n-alkoxy- benzyloxy) phenyl azomethine]-5-methyl thiazole and 2-[(4-n-alkoxy-benzyloxy)-2- hydroxy salicyladimine]-5-methyl thiazole, have been synthesized. They have been characterized by elemental analysis, FT-IR, 1HNMR, 13CNMR, and mass spectrometry. The liquid-crystalline behavior of these compounds was observed by differential scanning calorimetry (DSC) and polarizing microscopy. All the compounds of the 1,4-disubstituted series show an enantiotropic nematic phase only, whereas the compounds of the 1,3,4-trisubstituted series show smectic and nematic phases. Some mesogens with a lateral hydroxy group were also synthesized to evaluate the effect of this group on melting point, transition temperatures, and mesophase morphology.
- Thaker,Patel, Pranay,Vansadia,Patel
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- Synthesis and mesomorphic characterisation of chiral homologues
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Chiral liquid crystals have attracted considerable interest as they exhibit a good variety of modulated phases. We have synthesised a homologous series viz., 4-(4!-n-alkoxy benzoyloxy) benzylidene-4!!-1-(s)-methyl propoxy anilines, incorporating a terminal chiral centre, inorder to obtain better understanding of the relationship between molecular structure and appearance of SmC*phase in the molecules. It is observed that, in the present series the lower members upto butyl are pure nematogens, while pentyl to hexadecyl derivatives exhibit classical smectic as well as nematic mesophases. An additional smectic C* phase is observed in the middle octyl to dodecyl homologues. The homologues have been characterised by IR, NMR and DSC. Their mesomorphic properties have been compared with structurally related homologous series.
- Dave, Jayrang S.,Menon, Meera R.,Patel, Pratik R.
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p. 575 - 587
(2007/10/03)
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- Synthesis of new mesogenic homologous series with broken alkoxy chain
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A new mesogenic homologous series with broken alkoxy chain at the terminus of long polarizable molecules having following general formula have been synthesized. RO-C6H4-COO-C6H4-CH=N-C 6H4-COOCH2CH2OCH2CH 3 Where, R=-CnH2n+1; n=1 to 8, 10, 12, 14 and 16. All the members exhibit enantiotropic mesomorphism. Methoxy derivative is purely nematogenic. Ethoxy to n-hexyloxy derivatives exhibit enantiotropic smectic-A as well as nematic mesophases. n-Heptyloxy to n-hexadecyloxy derivatives exhibit only enantiotropic smectic A mesophases. The thermal stabilities and the commencement of smectic phase of the present series are compared with those of other structurally related series.
- Prajapati,Sharma,Chudgar
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p. 815 - 823
(2007/10/03)
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- The synthesis, mesomorphism and mesophase structure of anisotropic imines and their complexes with rhenium(I)
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Highly anisotropic imine ligands have been synthesised and complexed to Re(I). Two series of ligands and complexes were obtained with various chain lengths, showing smectic and nematic phases for the ligands and only a nematic phase for the complexes. The
- Liu, Xiao-Hua,Henirich, Benoit,Manners, Ian,Guillon, Daniel,Bruce, Duncan W.
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p. 637 - 644
(2007/10/03)
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- Synthesis and characterisation of rod-like metallomesogens of Mn(I) based on Schiff base ligands
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Complexation of liquid-crystalline imines to Mn(I) carbonyls led to liquid-crystalline complexes when the ligated imine was sufficiently anisotropic. Thus, all two-ring and some three-ring imine ligands were not mesomorphic when complexed, while some thre
- Liu, Xiao-Hua,Nurul Abser,Bruce, Duncan W.
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p. 271 - 280
(2007/10/03)
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- SYNTHESIS AND MESOMORPHISM OF COMPOUNDS CONTAINING DIAMINODIBENZO-18-CROWN-6 FRAGMENT
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A new series of compounds containing diaminodibenzo-18-crown-6 fragment was synthesized.Their mesomorphism and the influence of cis and trans substitution in the crown-ether fragment on the formation of the mesomorphic phase were studied.On heating, three compounds of this series form a nematic phase, which exists in the temperature range 50-80 deg C.
- Akopova, O. B.,Shabyshev, L. S.
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p. 604 - 610
(2007/10/02)
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- Mesomorphic Behavior of N,N'-Bis-3,3'-diaminodiphenylsulfones
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A new series of sulfur ligated siamese twin mesogens, N,N'-bis-3,3'diaminodiphenylsulfones has been studied for the thermotropic phase transition behavior.A stable or metastable nematic phase is exhibited by the methoxy
- Matsunaga, Y.,Yuri, T.
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p. 145 - 150
(2007/10/02)
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- Liquid-Crystalline Heterocycloalkanes. III. Synthesis and Liquid-Crystalline Properties of Substituted 1,3-Dioxadecalines
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Liquid-crystalline 2-substituted and 2,6-disubstituted 1,3-dioxadecalines (4-6) were synthesized by acid-catalyzed acetalization of trans-2-hydroxymethylcyclohexanol (1) or trans-4-alkyl-trans-2-hydroxymethylcyclohexanoles (2) with aldehydes 3 whereby the desired trans-isomers were formed only.The syntheses of the various aldehydes are also described.Special attention is drawn on the evolution of mesogenic properties of the title compounds 4-6 in comparison with known decalines and 1,3-dioxanes.It was found that the clearing temperatures of the synthesized 1,3-dioxadecalines are always lower than those of the corresponding decaline derivatives, due to the deformation of the decaline-ringsystem by the introduction of two oxygen-atoms.The comparison of 1,3-dioxanes and 1,3-dioxadecalines shows that the dioxadecaline ringsystem tends to suppress smectic mesophases in favour of nematics.A first example of a liquid crystalline cis-fused 1,3-dioxadecaline (8) is described, too.
- Tschierske, C.,Zaschke, H.
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- New Liquid Crystalline Homologous Series Exhibiting the Smectic C Phase
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A liquid cristalline homologous series of N--4-butylanilides and their hydroxyl derivatives at the 2-position were synthesized, and then the liquid-crystalline-phase transitions were determined using a differential scanning calorimeter and a polarizing microscope.All of the members exhibit a nematic phase, and a smectic C phase can be observed for the homologoues with a relatively long alkoxy chain.
- Sakagami, Sakumitshu
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p. 1153 - 1154
(2007/10/02)
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- The Preparation and Thermal Properties of Terminal Disubstituted N-(4-Benzoyloxybenzylidene)anilines
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The homologous series of N--4-(2-methylbutoxy)aniline (1), and N-benzylidene>-4-n-alkoxyaniline (2), and N--4-(2-methylbutoxy)aniline (3) where the 2-methylbutoxyl group has an S-configuration, have been prepared.Series 1 and 2 form a chiral smectic C (S*C) phase in addition to a cholesteric (Ch) and a chiral smectic G (S*G) phases, and series 3 form (S*C) and Ch phases.
- Takenaka, Shunsuke,Ikemoto, Tetsuya,Kusabayashi, Shigekazu
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p. 3965 - 3966
(2007/10/02)
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- APPLICATION OF LIQUID CRYSTALS FOR GAS-LIQUID CHROMATOGRAPHY.
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A liquid crystalline homologous series of N- left bracket 4-(4-alkoxybenzoyloxy)benzylidene right bracket -4-cyanoanilines was applied as a stationary liquid phase for the gas-liquid chromatographic separation of various positional isomers. It is shown that the nematic phase has higher selectivity for several positional isomers compared with the other mesomorphic phases.
- Sakagami,Nakamizo
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p. 1157 - 1158
(2007/10/02)
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- RECHERCHES SUR LES SUBSTANCES MESOGENES-VIII; PREPARATION ET PROPERTIES MESOMORPHES DE SERIES ISOMETRIQUES
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The synthesis and the mesomorphic properties of various series of isometric mesogenic compounds are described.It is confirmed that isometric mesogenic molecules may be nematogenic and/or smectogenic according to the position of the polar rigid core.
- Malthete, Jacques,Canceill, Josette,Gabard, Jacqueline,Jacques, Jean
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p. 2815 - 2821
(2007/10/02)
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