Ionic Liquid Crystals Based on Pyridinium Salts

Cı̂rcu, Viorel

doi:10.5772/65757

Cited by 9 publications

(5 citation statements)

References 65 publications

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“…For example, ion conduction is significantly enhanced in smectic A (SmA) and columnar phases as compared with the isotropic liquid phases. The unique properties of ILCs make them suitable for many technological applications including display technology, solar cells, ion conductors in batteries, and templates for the synthesis of nanomaterials [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. They are even considered as organized reaction media in which many organic reactions including Diels-Alder reactions; intramolecular Diels-Alder reactions can be performed with highly regio-and chemoselective reactions, with the additional advantage of being recycled [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Thermotropic Liquid-Crystalline and Light-Emitting Properties of Bis(4-aalkoxyphenyl) Viologen Bis(triflimide) Salts

et al. 2020

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A series of bis(4-alkoxyphenyl) viologen bis(triflimide) salts with alkoxy chains of different lengths were synthesized by the metathesis reaction of respective bis(4-alkoxyphenyl) viologen dichloride salts, which were in turn prepared from the reaction of Zincke salt with the corresponding 4-n-alkoxyanilines, with lithium triflimide in methanol. Their chemical structures were characterized by 1H and 13C nuclear magnetic resonance spectra and elemental analysis. Their thermotropic liquid-crystalline (LC) properties were examined by differential scanning calorimetry, polarizing optical microscopy, and variable temperature X-ray diffraction. Salts with short length alkoxy chains had crystal-to-liquid transitions. Salts of intermediate length alkoxy chains showed both crystal-to-smectic A (SmA) transitions, Tms, and SmA-to-isotropic transitions, Tis. Those with longer length of alkoxy chains had relatively low Tms at which they formed the SmA phases that persisted up to the decomposition at high temperatures. As expected, all of them had excellent thermal stabilities in the temperature range of 330–370 °C. Their light-emitting properties in methanol were also included.

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Section: Introductionmentioning

confidence: 99%

Thermotropic Liquid-Crystalline and Light-Emitting Properties of Bis(4-aalkoxyphenyl) Viologen Bis(triflimide) Salts

et al. 2020

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“…Their interesting properties result from the combination of liquid crystal (LC) and ionic liquid (IL) properties. The recent progress and development in the field of ILCs were reviewed in several publications [ 1 – 3 ]. There is a growing interest in ILs based on imidazolium cations.…”

Section: Introductionmentioning

confidence: 99%

Dielectric properties of a bisimidazolium salt with dodecyl sulfate anion doped with carbon nanotubes

Maximean

Cı̂rcu

Ganea

2018

Beilstein J. Nanotechnol.

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A new bisimidazolium salt with dodecyl sulfate as counterion has been designed and prepared. This salt shows a SmA phase that is stable at room temperature. The new ionic liquid crystal (ILC) was characterized by 1H NMR, 13C NMR and IR spectroscopy. Its liquid crystalline properties were analyzed by polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD) studies. The dielectric spectra of the ILC doped with different concentrations of carbon nanotubes (CNT) were recorded over a wide frequency and temperature range of 10−1 to 107 Hz and 293–338 K, respectively. The values of the activation energy were found in the range of 0.46–0.61 eV; the characteristic time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami functions. As a result of doping the ILC with CNT, the electric conductivity increases significantly. Ionic conductivity is dominant and it was indirectly observed through the electrode polarization (EP) effect. The very high dielectric permittivity values and the decrease of the electric conductivity at low frequencies confirm the presence of EP.

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“…It is known that pyridinium salts are a representative group of cationic compounds with a wide range of practically useful properties . Numerous ongoing studies show that many of them have strong antimicrobial action .…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Biological Evaluation of New Isatin‐Based QACs with High Antimicrobial Potency

et al. 2019

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A simple and easy condensation reaction of aryl‐ or N‐substituted isatins with Girard's reagents P and T was found to be useful in obtaining of water‐soluble isatin‐based quaternary ammonium compounds (QACs) bearing pyridinium or trimethylammonium moiety with high yields. Their antimicrobial activity was evaluated. Selective activity against Gram‐positive bacteria (S. aureus 209p and B. cereus 8035) and yeast‐like fungus Candida albicans 855–653 was shown. The influence of the substituent's nature as in the aromatic fragment as at position 1 on the activity was established. The most active are the pyridinium salts containing sterically hindered phenolic fragment at the position 1 of the heterocycle. The structures of all novel compounds were fully characterized using IR and NMR spectroscopies as well as XRD analysis.

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Ionic Liquid Crystals Based on Pyridinium Salts

Cited by 9 publications

References 65 publications

Thermotropic Liquid-Crystalline and Light-Emitting Properties of Bis(4-aalkoxyphenyl) Viologen Bis(triflimide) Salts

Thermotropic Liquid-Crystalline and Light-Emitting Properties of Bis(4-aalkoxyphenyl) Viologen Bis(triflimide) Salts

Dielectric properties of a bisimidazolium salt with dodecyl sulfate anion doped with carbon nanotubes

Synthesis and Biological Evaluation of New Isatin‐Based QACs with High Antimicrobial Potency

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