- Investigation of supramolecular architectures of bent-shaped pyridine derivatives: From a three-ring crystalline compound towards five-ring mesogens
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In search of novel photoactive liquid crystals, we have synthesized a series of five-ring pyridine-based bent-core compounds bearing different substituents at the peripheral phenyl rings (CH3O, Cl and NO2). Their mesomorphic behaviour has been investigated by polarizing optical microscopy, differential scanning calorimetry and X-ray scattering, and then compared with the unsubstituted parent compound. The introduction of the methoxy groups at the peripheral phenyl rings of the bent core results in a non-mesomorphic compound, whereas the chloro- and nitro-substituted compounds form enantiotropic B1-like phases. Significant changes in the textures and transition temperatures of the mesophase have been observed under UV light. The present investigation of the mesomorphic properties of the synthesized compounds, coupled with the analysis of the molecular packing of the related three-ring compounds, will help design self-organized molecules suitable for UV indicators.
- Tri?ovi?, Nemanja,Antanasijevi?, Jelena,Rogan, Jelena,Poleti, Dejan,Tóth-Katona, Tibor,Salamonczyk, Miroslaw,Jákli, Antal,Fodor-Csorba, Katalin
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p. 6977 - 6985
(2016/08/10)
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- Lobelane analogues containing 4-hydroxy and 4-(2-fluoroethoxy) aromatic substituents: Potent and selective inhibitors of [3H]dopamine uptake at the vesicular monoamine transporter-2
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A series of lobelane and GZ-793A analogues that incorporate aromatic 4-hydroxy and 4-(2-fluoroethoxy) substituents were synthesized and evaluated for inhibition of [3H]dopamine (DA) uptake at the vesicular monoamine transporter-2 (VMAT2) and th
- Joolakanti, Shyamsunder R.,Nickell, Justin R.,Janganati, Venumadhav,Zheng, Guangrong,Dwoskin, Linda P.,Crooks, Peter A.
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p. 2422 - 2427
(2016/07/07)
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- Solvatochromism of symmetrical 2,6-distyrylpyridines. An experimental and theoretical study
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Seven symmetrical 2,6-distyrylpyridines, phenyl-substituted with hydrogen-bond donors, hydrogen-bond acceptors, halogens and hydrophobic moieties were synthesized and their spectroscopic characterization was done. Solvent effects on the absorption and fluorescence spectra were analyzed and quantified using the Kamlet-Taft and Catalán approach. The obtained results were rationalized by comparison of electrostatic potentials of the molecules in the ground and in excited state and by comparison of the frontier molecular orbitals (HOMO and LUMO), derived from quantum-mechanical calculations (HF, DFT, MP2). Analysis of the results revealed an important influence of non-specific (dispersive) interactions on the solvatochromic behavior of the compounds. 1D and 2D NMR data, in silico obtained conformational assembly of the compound, and the NMR analysis of molecular flexibility in solution (NAMFIS), were used to estimate population of conformers and to deconvolute the UV-Vis spectrum of representative derivative; inferring that the conformational assembly is more complex than was assumed in so far published literature data for this class of compounds. Along with this, the emission spectra of the representative compounds were decomposed by the Multivariate Curve Resolution analysis.
- Markovi?, Jelena M.,Tri?ovi?, Nemanja P.,Mutavd?i?, Dragosav,Radoti?, Ksenija,Jurani?, Ivan O.,Drakuli?, Branko J.,Marinkovi?, Aleksandar D.
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supporting information
p. 435 - 446
(2014/09/16)
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- A structure-property relationship study of bent-core mesogens with pyridine as the central unit
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Three series of bent-core mesogens having pyridine as the central unit have been synthesized and characterized. A series of 2,6-diaminopyridine derivatives capable of forming inter- and intramolecular hydrogen bonds exhibit very high melting points. A decrease in the polarity of the central part of the bent-core obtained by replacing the amide with ester linkages results in derivatives with lower melting points and formation of B2- and B7-like mesophases. The introduction of the olefinic groups, which connect the pyridine ring with the inner aromatic rings, helps to further lower the polarity of the central part in the five ring system and led to the formation of B1 and B7 phases. The phases have been determined by optical microscopy observations and differential scanning calorimetry (DSC) and confirmed by X-ray studies. The bending angles and polarity of the investigated five-ring systems have been calculated by the density functional theory (DFT) method.
- Markovi?,Tri?ovi?,Tóth-Katona,Mil?i?,Marinkovi?,Zhang,Jákli,Fodor-Csorba
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p. 1751 - 1760
(2014/05/06)
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