- A new fullerene C60-didodecyloxy benzene dyad: An evidence for ground state electron transfer
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Synthesis, complete spectroscopic characterization and cyclic voltammetric measurements of a new didodecyloxybenzene-C60 dyad is described. The dyad showed distinct ground state intramolecular charge transfer as predicted from molecular orbital
- Gayathri, S. Shankara,Patnaik, Archita
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- Synthesis and mesomorphic characterization of some novel steroidal mesogens: A structure–property correlation
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The steroidal derivatives are found to be extremely good mesogens since their inception. Because of their inherent chirality, they have the potential to induce a wide variety of liquid crystalline phases, including frustrated phases depending upon the structure of the steroidal skeleton and the substituents attached. In this report, a series of novel monoalkoxy and dialkoxy benzoate derivatives of ergosterol and a few monoalkoxy derivatives of stigmasterol have been synthesized and their mesomorphic property has been investigated. The derivatives exhibited various mesophases including SmA, SmC*, N*, TGB and blue phases. Also, the gelation ability of some of these derivatives with various organic solvents has been examined. Furthermore, the mesomorphism of these derivatives has been compared with the analogous cholesteryl counterparts.
- Bhat S, Vanishree,Kumar, Sandeep,Raghunathan, V. A.
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- Hydrogen-bonding induced melamine-core supramolecular discotic liquid crystals
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Recognition of melamine is not only of importance for the food industry but also an interesting scientific research topic. The objective of this work is to screen suitable hydrogen-bonding complementary compounds for the construction of melamine-core supr
- Guo, Ling-Xiang,Liu, Yu-Han,Wang, Li,Wang, Meng,Lin, Bao-Ping,Yang, Hong
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supporting information
p. 9165 - 9173
(2017/09/22)
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- Synthesis and liquid crystalline properties of novel fluorinated N-benzoyl thiourea compounds. Effect of perfluoroalkyl chains on the thermal behavior and smectic phases stability
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A series of novel N-benzoyl-N’-aryl thiourea derivatives (BTU) bearing different number of alkoxy groups in terminal positions of benzoyl unit and a perfluorooctyl group on the other side have been designed and prepared. Their liquid crystalline properties were investigated by a combination of three techniques: polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and variable-temperature powder X-ray diffraction (XRD). Their thermal stability was studied by thermogravimetric analysis (TG). It was found that only the compounds which have only one alkoxy chain attached to benzoyl unit, 1a and 1b, show calamitic mesomorphic behavior, with smectic A and C phases being displayed. The type and stability of these mesophases are greatly influenced by the alkyl chain length as well as by the presence of perfluorooctyl group. The clearing and the mesophase ranges are significantly increased with the incorporation of perfluoroalkyl chains when compared to non-fluorinated analogues, with almost 40 °C. The attachment of additional alkoxy groups on the benzoyl moiety led to a significant decrease of the clearing points and suppression of the mesogenic character.
- Ili?, Monica,Micutz, Marin,Pasuk, Iuliana,Staicu, Teodora,C?rcu, Viorel
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- Molecular order and mesophase investigation of thiophene-based forked mesogens
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Thiophene-based rodlike molecules constructed from a three phenyl ring core and terminal dialkoxy chains recognized as forked mesogens are synthesized, and their mesophase properties as well as the molecular order are investigated. The synthesized forked
- Reddy, K. Rajasekhar,Lobo, Nitin P.,Narasimhaswamy
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p. 6897 - 6909
(2016/07/26)
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- Modular synthesis of amphiphilic Janus glycodendrimers and their self-assembly into glycodendrimersomes and other complex architectures with bioactivity to biomedically relevant lectins
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The modular synthesis of 7 libraries containing 51 self-assembling amphiphilic Janus dendrimers with the monosaccharides d-mannose and d-galactose and the disaccharide d-lactose in their hydrophilic part is reported. These unprecedented sugar-containing dendrimers are named amphiphilic Janus glycodendrimers. Their self-assembly by simple injection of THF or ethanol solution into water or buffer and by hydration was analyzed by a combination of methods including dynamic light scattering, confocal microscopy, cryogenic transmission electron microscopy, Fourier transform analysis, and micropipet-aspiration experiments to assess mechanical properties. These libraries revealed a diversity of hard and soft assemblies, including unilamellar spherical, polygonal, and tubular vesicles denoted glycodendrimersomes, aggregates of Janus glycodendrimers and rodlike micelles named glycodendrimer aggregates and glycodendrimermicelles, cubosomes denoted glycodendrimercubosomes, and solid lamellae. These assemblies are stable over time in water and in buffer, exhibit narrow molecular-weight distribution, and display dimensions that are programmable by the concentration of the solution from which they are injected. This study elaborated the molecular principles leading to single-type soft glycodendrimersomes assembled from amphiphilic Janus glycodendrimers. The multivalency of glycodendrimersomes with different sizes and their ligand bioactivity were demonstrated by selective agglutination with a diversity of sugar-binding protein receptors such as the plant lectins concanavalin A and the highly toxic mistletoe Viscum album L. agglutinin, the bacterial lectin PA-IL from Pseudomonas aeruginosa, and, of special biomedical relevance, human adhesion/growth-regulatory galectin-3 and galectin-4. These results demonstrated the candidacy of glycodendrimersomes as new mimics of biological membranes with programmable glycan ligand presentations, as supramolecular lectin blockers, vaccines, and targeted delivery devices.
- Percec, Virgil,Leowanawat, Pawaret,Sun, Hao-Jan,Kulikov, Oleg,Nusbaum, Christopher D.,Tran, Tam M.,Bertin, Annabelle,Wilson, Daniela A.,Peterca, Mihai,Zhang, Shaodong,Kamat, Neha P.,Vargo, Kevin,Moock, Diana,Johnston, Eric D.,Hammer, Daniel A.,Pochan, Darrin J.,Chen, Yingchao,Chabre, Yoann M.,Shiao, Tze C.,Bergeron-Brlek, Milan,Andre, Sabine,Roy, Rene,Gabius, Hans-J.,Heiney, Paul A.
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supporting information
p. 9055 - 9077
(2013/07/26)
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- Self-assembly of hekates-tris(N -salicylideneaniline)s into columnar structures: Synthesis and characterization
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Two series of new, photoluminescent star-shaped discotic liquid crystals, recently termed as "hekates", derived from tris(N-salicylideneaniline) s (TSANs), were synthesized by the facile threefold condensation of 3,4-bis(alkoxy)phenyl 4-aminobenzoates/3,4,5-tris(alkoxy) phenyl 4-aminobenzoates with 1,3,5-triformylphloroglucinol and characterized. These two series of discotics with six and nine peripheral n-alkoxy tails were especially designed and accomplished to understand the relation between mesomorphic/photophysical properties and molecular structure. Proton NMR spectral analysis revealed their existence as an inseparable mixture of two keto-enamine tautomeric forms featuring C3h and Cs rotational symmetries. A systematic study into the thermotropic liquid crystal behavior using polarizing optical microscopy, differential scanning calorimetry, and X-ray scattering confirmed the presence of columnar (Col) phase in vast majority of the TSANs prepared. The two-dimensional (2D) lattices of these fluid columnar phases were found to be characteristic of hexagonal Col (Col h), rectangular Col (Colr), or oblique Col (Col ob) phases depending on the number/length of the peripheral flexible chains. The stabilization of the Colob phase, a less commonly found fluid columnar structure, and the first of its kind in TSAN systems, implies very intensive intermolecular (face-to-face) interactions among the TSAN cores within the column. The photophysical properties were investigated both in solution and the columnar states by UV-vis absorption and photoluminescence; markedly, the solution state emits light in the blue region. The light-emitting ability of the Col phase is particularly significant given the possibility that, in such cores, the protons and electrons interact with each other through the H-bonding environment.
- Achalkumar, Ammathnadu S.,Hiremath, Uma S.,Rao, D. S. Shankar,Prasad, S. Krishna,Yelamaggad, Channabasaveshwar V.
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p. 527 - 544
(2013/03/13)
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- Self-assembly and liquid-crystalline supramolecular organizations of semifluorinated block co-dendritic supermolecules
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The synthesis and self-organizing behaviour into liquid-crystalline mesophases of two libraries of segmented block co-dendrimers are described. The overall structure of the dendritic supermolecules consists of two chemically incompatible molecular moietie
- Bury, Izabela,Heinrich, Benoit,Bourgogne, Cyril,Mehl, Georg H.,Guillon, Daniel,Donnio, Bertrand
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scheme or table
p. 452 - 468
(2012/03/22)
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- Self-assembly of imidazolium-based rodlike ionic liquid crystals: transition from lamellar to micellar organization
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By using aryl-amination chemistry, a series of rodlike 1-phenyl1H- imidazole-based liquid crystals (LCs) and related imidazolium-based ionic liquid crystals (ILCs) has been prepared. The number and length of the C-terminal chains (at the noncharged end of the rodlike core) and the length of the N-terminal chain (on the imidazolium unit in the ILCs) were modified and the influence of these structural parameters on the mode of self-assembly in LC phases was investigated by polarizing microscopy, differential scanning calorimetry, and X-ray diffraction. For the single-chain imidazole derivatives nematic phases (N) and bilayer SmA2 phases were found, but upon increasing the number of alkyl chains the LC phases were lost. For the related imidazolium salts LC phases were preserved upon increasing the number and length of the C-terminal chains and in this series it leads to the phase sequence SmA-columnar (Col)-micellar cubic (Cuby1/Pm3n). Elongation of the N-terminal chain gives the reversed sequence. Short Nterminal chains prefer an end-to-end packing of the mesogens in which these chains are separated from the C-terminal chains. Elongation of the N-terminal chain leads to a mixing of N- and C-terminal chains, which is accompanied by complete intercalation of the aromatic cores. In the smectic phases this gives rise to a transition from bilayer (SmA2) to monolayer smectic (SmA) phases. For the columnar and cubic phases the segregated end-to-end packing leads to core-shell aggregates. In this case, elongation of the N-terminal chains distorts core-shell formation and removes Cub1 and Col phases in favor of single-layer SmA phases. Hence, by tailoring the length of the N-terminal chain, a crossover from taper-shaped to polycatenar LC tectons was achieved, which provides a powerful tool for control of self-assembly in ILCs.
- Cheng, Xiaohong,Bai, Xueqing,Jing, Shan,Ebert, Helgard,Prehm, Marko,Tschierske, Carsten
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supporting information; experimental part
p. 4588 - 4601
(2010/08/19)
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- A new family of bent-core C2-symmetric liquid crystals
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A series of C2-symmetric compounds with different core sizes and varying lengths and numbers of alkoxy side chains were prepared, and the factors influencing their liquid crystalline mesophase behaviour were investigated. The compounds studied were based on benzophenone, dibenzylidene-acetone, and 1,9-diphenyl-nona-1,3,6,8-tetraen-5-one cores with either 1 or 2 linear alkoxy side chains. The side chains were varied in length from C6H13 to C12H25. The liquid crystalline mesophase behaviour of the compounds was investigated using differential scanning calorimetry, polarizing optical microscopy, and small-angle X-ray scattering (SAXS). It was found that a number of the molecules were able to self-assemble into smectic and nematic liquid crystalline phases.
- Hope-Ross, Kyle A.,Heiney, Paul A.,Kadla, John F.
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supporting information; experimental part
p. 639 - 645
(2010/08/21)
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- Supramolecular self-organization of "janus-like" diblock codendrimers: Synthesis, thermal behavior, and phase structure modeling
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We report on the design and synthesis of three series of segmented amphiphilic block codendrimers. and on their self-organizing behavior in liquid-crystalline mesophases. Connecting two prefunctionalized monodendrons, each differing in their chemical cons
- Bury, Izabela,Heinrich, Benoit,Bourgogne, Cyril,Guillon, Daniel,Donnio, Bertrand
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p. 8396 - 8413
(2007/10/03)
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- Bisfunctionalized Janus molecules
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(Matrix Presented) Bisfunctionalized dendritic multiester molecules were synthesized by combined protection-deprotection and divergent-convergent- divergent sequences in high yields leading to dendritic molecules that combine two functionally different su
- Ropponen, Jarmo,Nummelin, Sami,Rissanen, Kari
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p. 2495 - 2497
(2007/10/03)
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- Rodlike metallomesogens containing nickel(II), palladium(II) and copper(II) based on novel enaminoketonato ligands
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Several new enaminoketone mesogens were synthesized and coordinated to various metal salts to yield a variety of novel rodlike metal-containing liquid crystals. The mesophases were characterized by polarized optical microscopy (POM), differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). Whereas the free ligands display SmA and nematic mesophases, the Ni II and PdII complexes give rise to SmC and nematic phases, and the paramagnetic CuII mesogens to a narrow temperature-range nematic mesophase only. The magnetic behaviour of the latter was studied by means of EPR and magnetic susceptibility (SQUID) measurements.
- Roll, Carsten P.,Martin, Alexander G.,Goerls, Helmar,Leibeling, Guido,Guillon, Daniel,Donnio, Bertrand,Weigand, Wolfgang
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p. 1722 - 1730
(2007/10/03)
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- Tailoring thermotropic cubic mesophases: Amphiphilic polyhydroxy derivatives
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Novel amphiphilic polyhydroxy compounds [N-(3,4-dialkoxybenzoyl)-1-amino-1-deoxy-D-glucitols (glucamides), N-(3,4-dialkoxybenzoyl)-1-deoxy-1-methylamino-D-glucitols, N-(3,4,5-trialkoxybenzoyl)-1-deoxy-1-methylamino-D-glucitols (N-methylgucamides), 1-benzo
- Borisch, Konstanze,Diele, Siegmar,Goering, Petra,Kresse, Horst,Tschierske, Carsten
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p. 529 - 543
(2007/10/03)
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- The synthesis and mesomorphism of di-, tetra- and hexa-catenar liquid crystals based on 2,2′-bipyridine
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2,2′-Bipyridines are known to coordinate to a wide variety of metal centres. In this paper, liquid-crystalline two-chained (dicatenar), four-chained (tetracatenar) and six-chained (hexacatenar) bipyridines are synthesised and their mesomorphism is described. For the tetracatenar bipyridines, a full homologous series, from tetramethoxy to tetratetradecyloxy, was synthesised, and the phase diagram showed a classic progression from nematic and smectic C phases at short chain length, through a cubic phase to a columnar phase.
- Rowe, Kathryn E.,Bruce, Duncan W.
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p. 331 - 341
(2007/10/03)
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- Bent tridentate receptors in calamitic mesophases with predetermined photophysical properties: New luminescent lanthanide-containing materials
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A new synthetic strategy has been developed to introduce bent and rigid tridentate 2,6-bis(benzimidazol-2'-yl)pyridine cores into rodlike ligands L(11-17). The crystal structure of the nonmesogenic ligand L13 (C39H37N5O4, triclinic, P1, Z = 2) shows the expected trans-trans conformation of the tridentate binding unit, which provides a linear arrangement of the semirigid aromatic sidearms. The crystal structure of the related mesogenic ligand L16 (C61H81N5O4, triclinic, P1, Z = 2) demonstrates the fully extended conformation adopted by the lipophilic side chains, leading to a slightly helically twisted I-shaped molecule. A rich and varied mesomorphism results which can be combined with the simultaneous tuning of electronic and photophysical properties via a judicious choice of the spacers between the rigid central core and the semirigid lipophilic sidearms. Ligands L13,14 react with Ln(NO3)3·χH2O to give quantitatively and selectively the neutral 1:1 complexes [Ln(L')(NO3)3] (Ln = La to Lu), which are stable in the solid state at room temperature but partially dissociate in acetonitrile to give the cationic species [Ln(L')(NO3)2]+. The crystal structure of [Lu-(L13)(NO3)3]·3CH3CN (30, LUC45H46N11O13, monoclinic, C2/c, Z = 8) reveals a U-shaped arrangement of the ligand strand arising from the cis-cis conformation of the coordinated tridentate binding unit. This drastic geometric change strongly affects the thermal behavior and the photophysical and electronic properties of the lipophilic complexes [Ln(L14)(NO3)3]. Particular attention has been focused on structure-properties relationships, which can be modulated by the size of the lanthanide metal ions.
- Nozary, Homayoun,Piguet, Claude,Tissot, Paul,Bernardinelli, Gérald,Bünzli, Jean-Claude G.,Deschenaux, Robert,Guillon, Daniel
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p. 12274 - 12288
(2007/10/03)
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- Influence of lateral alkoxy substitution on mesomorphic properties of copper complexes
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Coordination complexes between copper and some lateral alkoxy chain-substituted N-(4-(4'-alkoxybenzoyloxy)salicylidene)-4-n-butylaniline have been synthesized.The lateral chain was introduced on the outer ring bearing the ester function.In the case of a 3,4-disubstitution, the mesomorphic behavior is related to the number of carbons in the terminal chain.If this is too small, the mesomorphic properties of the complexes disappear.In contrast, copper complexes are liquid crystalline and show more ordered phases by comparison with the free ligand.In case of a 2,4-disubstitution, the phases are nematic and the clearing temperatures are near room temperature, but the observed phases are essentially monotropic for the ligands, as well as for the complexes.Keywords: nematic / copper complex / lateral substitution / Schiff base
- Berdague, Philippe,Perez, Felix,Courtieu, Jacques,Bayle, Jean-Pierre
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p. 335 - 343
(2007/10/02)
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