Oxadiazolyl-Pyridinium as Cationic Scaffold for Fluorinated Ionic Liquid Crystals

The synthesis and characterization of a new class of 1,2,4-oxadiazolylpyridinium as a cationic scaffold for fluorinated ionic liquid crystals is herein described. A series of 12 fluorinated heterocyclic salts based on a 1,2,4-oxadiazole moiety, connected through its C(5) or C(3) to an N-alkylpyridinium unit and a perfluoroheptyl chain, differing in the length of the alkyl chain and counterions, has been synthesized. As counterions iodide, bromide and bis(trifluoromethane)sulfonimide have been considered. The synthesis, structure, and liquid crystalline properties of these compounds are discussed on the basis of the tuned structural variables. The thermotropic properties of this series of salts have been investigated by differential scanning calorimetry and polarized optical microscopy. The results showed the existence of an enantiotropic mesomorphic smectic liquid crystalline phase for six bis(trifluoromethane)sulfonimide salts.

Download Full-text

Long-alkyl-chain-derivatized imidazolium salts and ionic liquid crystals with tailor-made properties

RSC Advances ◽

10.1039/c3ra47250g ◽

2014 ◽

Vol 4 (24) ◽

pp. 12476-12481 ◽

Cited By ~ 29

Author(s):

Xinjiao Wang ◽

Michelle Sternberg ◽

Florian T. U. Kohler ◽

Berthold U. Melcher ◽

Peter Wasserscheid ◽

...

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Liquid Crystals ◽

Liquid Crystalline ◽

Alkyl Chain ◽

Imidazolium Salts ◽

Crystalline Materials ◽

Ionic Liquid Crystals ◽

Liquid Crystalline Materials ◽

Long Alkyl Chain

New ionic liquids and ionic liquid crystalline materials with custom-tailored properties were synthesized based on long-alkyl-chain-derivatized 1,3-dialkylimidazolium salts.

Download Full-text

Liquid-crystalline behaviour and electrorheological effect of phthalocyanine-based ionic liquid crystals

Liquid Crystals ◽

10.1080/02678292.2020.1861347 ◽

2020 ◽

pp. 1-10

Author(s):

Aikebaier Reheman ◽

Shuangying Hu ◽

Lianjun Cao ◽

Danhua Xie ◽

Guiyang Yan ◽

...

Keyword(s):

Ionic Liquid ◽

Liquid Crystals ◽

Liquid Crystalline ◽

Electrorheological Effect ◽

Ionic Liquid Crystals

Download Full-text

Design of Ionic Liquid Crystals Forming Normal-Type Bicontinuous Cubic Phases with a 3D Continuous Ion Conductive Pathway

Crystals ◽

10.3390/cryst9060309 ◽

2019 ◽

Vol 9 (6) ◽

pp. 309 ◽

Cited By ~ 2

Author(s):

Takahiro Ichikawa ◽

Yui Sasaki ◽

Tsubasa Kobayashi ◽

Hikaru Oshiro ◽

Ayaka Ono ◽

...

Keyword(s):

Ionic Liquid ◽

Liquid Crystals ◽

Ionic Conductivity ◽

Liquid Crystalline ◽

Alkyl Chain ◽

Normal Type ◽

Ion Conduction ◽

Cubic Phases ◽

Bicontinuous Cubic ◽

Chain Lengths

We have prepared a series of pyridinium-based gemini amphiphiles. They exhibit thermotropic liquid–crystalline behavior depending on their alkyl chain lengths and anion species. By adjusting the alkyl chain lengths and selecting suitable anions, we have obtained an ionic amphiphile that exhibits a normal-type bicontinuous cubic phase from 38 °C to 12 °C on cooling from an isotropic phase. In the bicontinuous cubic liquid–crystalline assembly, the pyridinium-based ionic parts align along a gyroid minimal surface forming a 3D continuous ionic domain while their ionophobic alkyl chains form 3D branched nanochannel networks. This ionic compound can form homogeneous mixtures with a lithium salt and the resultant mixtures keep the ability to form normal-type bicontinuous cubic phases. Ion conduction measurements have been performed for the mixtures on cooling. It has been revealed that the formation of the 3D branched ionophobic nanochannels does not disturb the ion conduction behavior in the ionic domain while it results in the conversion of the state of the mixtures from fluidic liquids to quasi-solids, namely highly viscous liquid crystals. Although the ionic conductivity of the mixtures is in the order of 10–7 S cm–1 at 40 °C, which is far lower than the values for practical use, the present material design has a potential to pave the way for developing advanced solid electrolytes consisting of two task-specific nanosegregated domains: One is an ionic liquid nano-domain with a 3D continuity for high ionic conductivity and the other is ionophobic nanochannel network domains for high mechanical strength.

Download Full-text

Liquid-crystalline behavior and ferroelectric property of viologen-based ionic liquid crystals

Journal of Molecular Liquids ◽

10.1016/j.molliq.2019.112369 ◽

2020 ◽

Vol 301 ◽

pp. 112369 ◽

Cited By ~ 1

Author(s):

Yanxing Zheng ◽

Jiwei Wang ◽

Xinqiao Tang ◽

Lei Zhang ◽

Fanbao Meng

Keyword(s):

Ionic Liquid ◽

Liquid Crystals ◽

Ferroelectric Property ◽

Liquid Crystalline ◽

Ionic Liquid Crystals

Download Full-text

Synthesis and thermotropic properties of new green electrochromic ionic liquid crystals

New Journal of Chemistry ◽

10.1039/c9nj03303c ◽

2019 ◽

Vol 43 (46) ◽

pp. 18285-18293 ◽

Cited By ~ 7

Author(s):

Lucia Veltri ◽

Gabriella Cavallo ◽

Amerigo Beneduci ◽

Pierangelo Metrangolo ◽

Giuseppina Anna Corrente ◽

...

Keyword(s):

Ionic Liquid ◽

Liquid Crystal ◽

Liquid Crystals ◽

Small Molecules ◽

Ionic Liquid Crystals ◽

Thermotropic Properties

New liquid crystal viologens, which exhibit green electrochromic behavior in the LC phase, rarely observed for small molecules, have been developed.

Download Full-text

Study on the thermotropic properties of highly fluorinated 1,2,4-oxadiazolylpyridinium salts and their perspective applications as ionic liquid crystals

Journal of Materials Chemistry ◽

10.1039/b615190f ◽

2007 ◽

Vol 17 (12) ◽

pp. 1201 ◽

Cited By ~ 52

Author(s):

Fabrizio Lo Celso ◽

Ivana Pibiri ◽

Alessandro Triolo ◽

Roberto Triolo ◽

Andrea Pace ◽

...

Keyword(s):

Ionic Liquid ◽

Liquid Crystals ◽

Ionic Liquid Crystals ◽

Thermotropic Properties

Download Full-text

NMR Spectroscopic Studies of Cation Dynamics in Symmetrically-Substituted Imidazolium-Based Ionic Liquid Crystals

International Journal of Molecular Sciences ◽

10.3390/ijms21145024 ◽

2020 ◽

Vol 21 (14) ◽

pp. 5024

Author(s):

Debashis Majhi ◽

Andrei V. Komolkin ◽

Sergey V. Dvinskikh

Keyword(s):

Ionic Liquid ◽

Liquid Crystals ◽

Liquid Crystalline ◽

Orientational Order ◽

Soft Materials ◽

Spectroscopic Studies ◽

Single Chain ◽

Self Assembling ◽

Ionic Liquid Crystals ◽

Cation Size

Ionic liquid crystals (ILCs) present a new class of non-molecular soft materials with a unique combination of high ionic conductivity and anisotropy of physicochemical properties. Symmetrically-substituted long-chain imidazolium-based mesogenic ionic liquids exhibiting a smectic liquid crystalline phase were investigated by solid state NMR spectroscopy and computational methods. The aim of the study was to reveal the correlation between cation size and structure, local dynamics, and orientational order in the layered mesophase. The obtained experimental data are consistent with the model of a rod-shaped cation with the two chains aligned in opposite directions outward from the imidazolium core. The alignment of the core plane to the phase director and the restricted conformations of the chain segments were determined and compared to those in single-chain counterparts. The orientational order parameter S~0.5–0.6 of double-chain ionic liquid crystals is higher than that of corresponding single-chain analogues. This is compatible with the enhanced contribution of van der Waals forces to the stabilization of smectic layers. Increased orientational order for the material with Br− counterions, which exhibit a smaller ionic radius and higher ability to form hydrogen bonds as compared to that of BF4−, also indicated a non-negligible influence of electrostatic and hydrogen bonding interactions. The enhanced rod-shape character and higher orientational order of symmetrically-substituted ILCs can offer additional opportunities in the design of self-assembling non-molecular materials.

Download Full-text