- Chemical programming of the domain of existence of liquid crystals
-
This work illustrates how enthalpy and entropy changes responsible for successive phase transitions of cyanobiphenyl-based liquid crystals can be combined to give cohesive free energy densities. These new parameters are able to rationalize and quantify the demixing of the melting and clearing processes that occur in thermotropic liquid crystals. Minor structural variations at the molecular level can be understood as pressure increments that alter either the melting or clearing temperatures in a predictable way. This assessment of microsegregation operating in amphiphilic molecules paves the way for the chemical programming of the domain of existence of liquid-crystalline phases. Changing states: The cohesive free energy density concept (CFED) is applied to thermotropic cyanobiphenyl-based liquid crystals to establish predictive quantitative correlations between each antagonist segments of the amphiphilic molecules (flexible alkyl tail/rigid aromatic core) and their transition temperatures (solid→liquid crystalline/liquid crystalline→ isotropic liquid; see figure).
- Dutronc, Thibault,Terazzi, Emmanuel,Gune, Laure,Buchwalder, Kerry-Lee,Floquet, Sbastien,Piguet, Claude
-
supporting information
p. 1385 - 1391
(2016/01/25)
-
- N- and O-acylated phthalocyanines with gallic acid moieties
-
Phthalocyanines containing gallic acid moieties were synthesized and investigated by the method of electron absorption spectroscopy. It was shown that in organic solvents the prepared phthalocyanines exist predominantly in associated form.
- Tikhomirova,Maizlish,Borisov,Shaposhnikov
-
p. 1339 - 1344
(2016/08/10)
-
- Side-on main-chain liquid crystalline polymers prepared by acyclic diene metathesis polymerization and thiol-ene click step-growth polymerization
-
In this manuscript, we design and synthesize a series of X-shaped mesogenic monomers, bearing two terminal-alkene tails. Starting from these X-shaped monomers, acyclic diene metathesis polymerization and thiol-ene polyaddition are applied for the first time to prepare two series of side-on main-chain liquid crystalline polymers (LCPs), respectively. The mesomorphic behaviors and structure-property relationships of these new polymers are studied in detail by a combination of 1H NMR, GPC, TGA, DSC, POM, and XRD experiments. It turns out that the length of alkoxy terminal chains of the embedded mesogens and the length of the spacer connecting two adjacent mesogens on the polymer backbones markedly influence the mesomorphic properties. Furthermore, a side-on main-chain liquid crystalline elastomer fiber is prepared by crosslinking the LCP using a UV-sensitive bifunctional benzophenone crosslinker. In comparison with the pure polymer fiber's monodomain alignment, the crosslinked elastomer fiber however shows nonaligned polydomain structure, probably due to the order competitions between the mixed crosslinkers, mesogens, and polymer backbones. 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1086-1098 A series of X-shaped mesogenic monomers bearing two polymerizable terminal-alkene tails are designed and synthesized. Starting from these X-shaped monomers, acyclic diene metathesis polymerization (ADMET) and thiol-ene click step-growth polymerization are applied to prepare two series of side-on main-chain liquid crystalline polymers, respectively. Copyright
- Yang, Hong,Lv, You-Jing,Lin, Bao-Ping,Zhang, Xue-Qin,Sun, Ying,Guo, Ling-Xiang
-
p. 1086 - 1098
(2014/03/21)
-
- Spirocyclic 2,5-dihydro-1H-imidazole 1-oxyl radicals with a mesogenic substituent on C4. Synthesis and crystal structure
-
Stable spirocyclic 2,5-dihydro-1H-imidazole 1-oxyl radicals containing a mesogenic fragment were synthesized on the basis of 1-[4-hydroxy(alkoxy)phenyl]- 2-hydroxyamino-2-methylpropan-1-ones. The crystalline structure of two aminoxyl radicals was determin
- Zaytseva,Gatilov,Amitina,Tamura,Grigor'Ev,Mazhukin
-
-
- New spirocyclic nitroxides of 2,5-dihydroimidazole series flanked by two mesogenic fragments
-
N/C-Hydroxylated spirofused derivatives of 2,5-dihydroimidazole which were synthesized by condensation of 4-(4-hydroxyphenyl)cyclohexanone with aryl hydroxylaminoalkyl ketones in the presence of ammonia were determined to be trans-ee-isomers of 1,4-cycloh
- Zaytseva, Elena V.,Shernyukov, Andrey V.,Genaev, Alexander M.,Tamura, Rui,Grigor'ev, Igor A.,Mazhukin, Dmitrii G.
-
-
- IMIDAMIDE SPHINGOSINE KINASE INHIBITORS
-
Imidamide (amidine) analogs that can inhibit the activity of sphingosine kinase 1 and sphingosine kinase 2 (SphK1 and SphK2) are provided. The compounds can prevent angiogenesis in tumors.
- -
-
Page/Page column 23
(2012/09/05)
-
- Development of amidine-based sphingosine kinase 1 nanomolar inhibitors and reduction of sphingosine 1-phosphate in human leukemia cells
-
Sphingosine 1-phosphate (S1P) is a bioactive lipid that has been identified as an accelerant of cancer progression. The sphingosine kinases (SphKs) are the sole producers of S1P, and thus, SphK inhibitors may prove effective in cancer mitigation and chemosensitization. Of the two SphKs, SphK1 overexpression has been observed in a myriad of cancer cell lines and tissues and has been recognized as the presumptive target over that of the poorly characterized SphK2. Herein, we present the design and synthesis of amidine-based nanomolar SphK1 subtype-selective inhibitors. A homology model of SphK1, trained with this library of amidine inhibitors, was then used to predict the activity of additional, more potent, inhibitors. Lastly, select amidine inhibitors were validated in human leukemia U937 cells, where they significantly reduced endogenous S1P levels at nanomolar concentrations.
- Kennedy, Andrew J.,Mathews, Thomas P.,Kharel, Yugesh,Field, Saundra D.,Moyer, Morgan L.,East, James E.,Houck, Joseph D.,Lynch, Kevin R.,MacDonald, Timothy L.
-
p. 3524 - 3548
(2011/07/07)
-
- Phthalonitriles containing ester groups and copper phthalocyanines based on them
-
Phthalonitriles containing ester groups were obtained by acylation of 4-hydroxyphthalonitrile and esterification of 4-(p-carboxyphenyloxy) phthalonitriles. On the basis of these phthalonitriles the respective copper phthalocyanines were synthesized. Spectral and some other physical and chemical properties of the synthesized compounds were investigated.
- Tikhomirova,Maizlish,Shaposhnikov
-
scheme or table
p. 768 - 772
(2011/08/09)
-
- Liquid crystalline properties of 3-[4-(4′- alkoxybenzoyloxybenzylidene) amino]-1,2,4-triazines: Synthesis and characterization
-
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
-
experimental part
p. 127 - 137
(2010/09/05)
-
- Liquid crystalline properties of unsymmetrical N-(o-hydroxybenzylidene)- N′-(4-n-alkoxybenzoyloxybenzylidene)azines: Synthesis and characterization
-
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
-
experimental part
p. 148 - 158
(2010/09/05)
-
- Liquid crystalline properties of 2,5-bis[4-n-alkoxybenzoyloxy-(4- benzoyloxy)]-3,6-dichloro-1,4-benzoquinones: Synthesis and characterization
-
A new series of 2,5-bis[4-n-alkoxybenzoyloxy-(4-benzoyloxy)]-3,6-dichloro- 1,4-benzoquinones, C6Cl2O2(OCOC 6H4OCOC6H4OR)2, where R=CmH2m+1 and m=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 spectra. Mesomorphic properties of these compounds were studied by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The mesomorphic nature of these compounds depends on the alkoxy chain length. The compounds (m=7, 8, 9, 10) exhibit a monotropic nematic mesophase in cooling cycle, while the compounds (m=11, 12, 14, and 16) show no mesogenic behavior in both heating and cooling cycles. The intermolecular interactions play a vital role in the mesogenic nature of these compounds. In higher homologues of the series the intermolecular interactions become more prominent leading to loss in mesogenic nature. Copyright Taylor & Francis Group, LLC.
- Singh, Bachcha,Pandey, Ashwini
-
experimental part
p. 138 - 147
(2010/09/05)
-
- Symmetric bent-core mesogens with m-carborane and adamantane as the central units
-
Several members of two homologous series of symmetric bent-shaped compounds with either m-carborane or adamantane (1[n] or 2[n], n = 9-13) in the central position were synthesized and investigated by optical, calorimetric, X-ray diffraction, and electro-o
- Pociecha, Damian,Ohta, Kiminori,Januszko, Adam,Kaszynski, Piotr,Endo, Yasuyuki
-
supporting information; experimental part
p. 2978 - 2982
(2010/03/26)
-
- The design and investigation of laterally functionalised oxadiazoles
-
The synthesis of new [1,3,4]-oxadiazole-based mesogens with nematic phase behaviour at low temperature is described, and their characterisation by OPM, DSC and XRD is reported. The Royal Society of Chemistry.
- Apreutesei, Daniela,Mehl, Georg H.
-
experimental part
p. 4711 - 4715
(2009/09/25)
-
- Directed Metalation Route to Ferroelectric Liquid Crystals with a Chiral Fluorenol Core: The Effect of Restricted Rotation on Polar Order
-
A new series of smectic C* (SmC*) mesogens containing a chiral (R)-2-octyloxy side chain and either a fluorenone (2a-e) or chiral fluorenol (3a-e) core were synthesized using a combined directed ortho metalation-directed remote metalation strategy. The Sm
- McCubbin, J. Adam,Tong, Xia,Wang, Ruiyao,Zhao, Yue,Snieckus, Victor,Lemieux, Robert P.
-
p. 1161 - 1167
(2007/10/03)
-
- New banana-shaped thiobenzoate liquid crystals with B6, B1 and B2 phases
-
A new series of achiral banana-shaped compounds ("Sn") has been synthesised and studied by the classical techniques (optical microscopy, differential scanning calorimetry, X-ray diffraction and electro-optic investigations). The short homologues (S6,S7) present an intercalated smectic B6 and a two-dimensional B1 phase. The intermediate S8-S10 compounds only form a B1 phase while the mesophase of long homologues (S11-S16) is identified as a switchable smectic B2 mesophase.
- Rouillon,Marcerou,Laguerre,Nguyen,Achard
-
p. 2946 - 2950
(2007/10/03)
-
- Calamitic organometallic liquid crystals with terminal metal. Syntheses and liquid crystal properties of dicarbonylrhodium(I) β-diketonate complexes
-
A series of novel organometallic complexes based on γ-substituted β-diketone ligands with terminal metal Rh(I) have been prepared by reaction of the ligands with [Rh(CO)2(μ-Cl)]2. The mesomorphism of the ligands and complexes has been investigated using DSC and polarizing microscope. It is found that non-mesogenic ligands with n=7, 8, 9, 10, 11 can form liquid crystalline phase by direct coordination to metal. The effect of the terminal carbon number on the mesomorphism has also been discussed.
- Wan, Wen,Guang, Wen-Jie,Zhao, Ke-Qin,Zheng, Wei-Zhong,Zhang, Liang-Fu
-
p. 157 - 161
(2007/10/03)
-
- Synthesis, mesomorphic behaviour and the uniaxial nature of 1,2,4,5-tetra-(4-alkoxybenzoyloxy)benzenes
-
A homologous series of 1,2,4,5-tetra-(4-alkoxybenzoyloxy)benzenes (2, R = C4H9, C6H13 to C16H33 and C18H37) has been synthesised. Optical microscopy revealed that the compounds with R = C4H9, C6H13 to C10H21 have a nematic phase, compounds with R = C11H23 to C14H29 have nematic and smectic C phases and compounds with R = C15H31, C16H33 and C18H37 have only a smectic C phase. The TN-I values show an 'odd-even' alternation which is typical of calamitic systems. The refractive indices for aligned samples of compound 2h (R = C10H21) demonstrate that the nematic phase is uniaxial.
- Amilaprasadh Norbert,Goodby,Hird,Toyne,Cliff,Patel
-
p. 339 - 350
(2007/10/02)
-
- 1,1'-Disubstituted Ferrocene-Containing Thermotropic Liquid Crystals of Structure 5-C5H4)COOC6H4XC6H4OCnH2n+1>2> (X=OOC or COO). Influence of the Orientation of the Central Ester Function on the Mesogenic Properties
-
The two series I and II of 1,1'-disubstituted ferrocenes which differ by the direction of the ester function included the rigid organic part were synthesized and their liquid crystal properties examined.These latter were found to be strongly dependent on the orientation of the connecting ester group and on the alkyl chain.
- Deschenaux, Robert,Marendaz, Jean-Luc,Santiago, Julio
-
p. 865 - 876
(2007/10/02)
-
- Synthesis of Some Chiral Smectics with Chloroalkoxy Side Chains
-
We have synthesized two new series of chiral esters, the (R)-4'-(2-chloropropoxy)phenyl 4-alkoxybenzoates (3) and the (R)-4'-(2-chloropropoxy)phenyl 4-alkoxycinnamates (4).Compounds belonging to the former series mainly exhibit smectic A phases at moderate temperatures (about 50 deg C) while the compounds of the latter series show A phases at somewhat higher temperatures.Some members of both series show, in addition, a cholesteric or a smectic B phase but tilted are not found at all.Keywords: chiral smectics, phenyl benzoates, phenyl cinnamates.
- Alstermark, Christer,Nilsson, Martin,Otterholm, Bengt
-
p. 277 - 288
(2007/10/02)
-
- RECHERCHES SUR LES SUBSTANCES MESOGENES-VIII; PREPARATION ET PROPERTIES MESOMORPHES DE SERIES ISOMETRIQUES
-
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
-
p. 2815 - 2821
(2007/10/02)
-
- SYNTHESIS AND MESOMORPHIC PROPERTIES OF THE HOMOLOGOUS SERIES OF 4-ALKYL OR ALKOXY-4 prime -BROMO OR CYANOTOLANES.
-
A homologous series of 4-alkyl or alkoxy-4 prime -bromo or cyanotolanes in which the alkyl group is C//4 yields C//1//0 and the alkoxy group is C//1 yields C//1//2, was prepared. Interphase transitions between solid, mesomorphic and isotropic phases were studied by hot stage microscopy and differential scanning calorimeter. The bromo compounds have a smectic polymorphism. Three pure products of cyano derivatives with the chains C//9H//1//9O, C//1//0H//2//1O amd C//1//0H//2//1 present an enantiotropic or monotropic reentrant nematic phase at atmospheric pressure. The reentrant phenomenon itself is discussed as well as the absence of correlation between T//N//A/T//N//I McMillan parameter and the heat of transition. A plot of the nematic isotropic transition temperatures against the number of carbon atoms in the alkoxy chain shows the usual odd even effect.
- Tinh,Pourrere,Destrade
-
p. 125 - 139
(2007/10/02)
-