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Joseph J, Raya J, Palmino F, Jeannoutot J, Berville M, Weiss J, Chérioux F, Wytko JA. Self-assembled viologens on HOPG: solid-state NMR and AFM unravel the location of the anions. NANOSCALE 2024; 16:13089-13095. [PMID: 38904940 DOI: 10.1039/d4nr00894d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The controlled growth of self-assembled networks on surfaces based on viologen salts is a major scientific challenge due to their unique electronic properties. The combination of solid-state NMR spectroscopy and atomic force microscopy at ambient conditions can unravel the fine organization of the supramolecular network on a graphitic surface by positioning the counter-ions relative to the viologen cation.
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Affiliation(s)
- Jean Joseph
- Institut de Chimie, UMR 7177 CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67008 Strasbourg, France.
| | - Jésus Raya
- Institut de Chimie, UMR 7177 CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67008 Strasbourg, France.
| | - Frank Palmino
- Université Franche-Comté, CNRS, FEMTO-ST, 25000 Besançon, France.
| | | | - Mathilde Berville
- Institut de Chimie, UMR 7177 CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67008 Strasbourg, France.
| | - Jean Weiss
- Institut de Chimie, UMR 7177 CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67008 Strasbourg, France.
| | | | - Jennifer A Wytko
- Institut de Chimie, UMR 7177 CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67008 Strasbourg, France.
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2
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Mohammad AT, Abbas WR. Liquid crystal behavior, photoluminescence and gas sensing: A new series of ionic liquid crystal imidazole and benzoimidazole bearing chalcone groups, synthesis and characterization. RSC Adv 2021; 11:38444-38456. [PMID: 35493216 PMCID: PMC9044318 DOI: 10.1039/d1ra07731g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/11/2021] [Indexed: 11/21/2022] Open
Abstract
Four new series of chalcones containing imidazole bromonium and benzimidazole bromonium salts with spacer alkyl chains (C n , n = 2 and 4) were synthesized and the chemical structure, thermal behavior, photoluminescence and gas sensing were characterized by several technical methods. The studies have indicated similar mesomorphic properties of the synthesized compounds, dependent on the terminal alkyl-chain and lengths of the alkoxy-spacer. Almost compounds with shorter alky chains, 4a-4e, 5a-5c, 6a-6c and 7a-7d, did not show liquid crystal properties, while the results of other compounds confirm the existence of smectic A in cooling and heating cycles. Photoluminescence of compounds 5a-5i and 7a-7i was also studied. The emission in the blue region reveals that the material has blue light emission properties. Sensing behavior of compounds 4i and 5i was investigated for NH3 and NO2 gases. The sensors exhibited high sensitivity toward NH3, while sensitivity toward the oxidizing gas NO2 is lower.
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Affiliation(s)
| | - Wahaj Raed Abbas
- Chemistry Department, College of Science, University of Anbar Ramadi Iraq +9647832575081
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3
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Chowdhury S, Reynard-Feytis Q, Roizard C, Frath D, Chevallier F, Bucher C, Gibaud T. Light-Controlled Aggregation and Gelation of Viologen-Based Coordination Polymers. J Phys Chem B 2021; 125:12063-12071. [PMID: 34677961 DOI: 10.1021/acs.jpcb.1c06090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Ditopic bis-(triazole/pyridine)viologens are bidentate ligands that self-assemble into coordination polymers. In such photo-responsive materials, light irradiation initiates photo-induced electron transfer to generate π-radicals that can self-associate to form π-dimers. This leads to a cascade of events: processes at the supramolecular scale associated with mechanical and structural transition at the macroscopic scale. By tuning the irradiation power and duration, we evidence the formation of aggregates and gels. Using microscopy, we show that the aggregates are dense, polydisperse, micron-sized, spindle-shaped particles which grow in time. Using microscopy and time-resolved micro-rheology, we follow the gelation kinetics which leads to a gel characterized by a correlation length of a few microns and a weak elastic modulus. The analysis of the aggregates and the gel states vouch for an arrested phase separation process, a new scenario to supramolecular systems.
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Affiliation(s)
- Shagor Chowdhury
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Quentin Reynard-Feytis
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Clément Roizard
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Denis Frath
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Floris Chevallier
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Christophe Bucher
- Laboratoire de Chimie, Université de Lyon, Ens de Lyon, CNRS UMR 5182, F69342 Lyon, France
| | - Thomas Gibaud
- Laboratoire de Physique, Université de Lyon, Ens de Lyon, University Claude Bernard, CNRS, F69342 Lyon, France
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4
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Saielli G. The effect of hydration on the stability of ionic liquid crystals: MD simulations of [C 14C 1im]Cl and [C 14C 1im]Cl·H 2O. Phys Chem Chem Phys 2021; 23:24386-24395. [PMID: 34676847 DOI: 10.1039/d1cp03757a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The thermal range of the stability of Ionic Liquid Crystal (ILC) phases of imidazolium ILCs, and the type of the mesophase itself are affected by several molecular structural features, the two prominent ones being the alkyl chain length and the counter-anion. Hydration is also very important: monohydrate samples of 1-alkyl-3-methylimidazolium halides have a higher clearing point and a wider thermal range of the stability of the ionic smectic phase, compared with the analogous anhydrous sample. To understand the reasons, at a microscopic level, for such increased stability due to hydration, we run classical Molecular Dynamics (MD) simulations of a typical ionic liquid crystal, 1-tetradecyl-3-methylimidazolium chloride, and of its monohydrate form. We tested a full-charge non-polarizable force field and a scaled-charge version having the total charge of the ions scaled by a factor of 0.80. Comparison of the structural and dynamic properties with available experimental data reveals that the scaling of the charge by a factor of 0.80 results in a good agreement between simulated and experimental data and it sheds light on the microscopic mechanism responsible for the increased stability of the monohydrated phase. A hydrogen-bond network between water and the chloride anion is established in the ionic layer which increases the stability of the ionic layer; this in turn increases the nano-segregation between the ionic and hydrophobic layers which eventually produce an increased order of the alkylic layer as well.
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Affiliation(s)
- Giacomo Saielli
- CNR Institute on Membrane Technology, Padova Section, Via Marzolo, 1-35131 Padova, Italy. .,Department of Chemical Sciences, University of Padova, Via Marzolo, 1-35131 - Padova, Italy
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The Influence of the Nature of Redox-Active Moieties on the Properties of Redox-Active Ionic Liquids and on Their Use as Electrolyte for Supercapacitors. ENERGIES 2021. [DOI: 10.3390/en14196344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this work, two new redox-active ionic liquids, one based on 2,2,6,6-tetramethylpiperidine-N-oxide and the other based on 4,4′-bipyridine, are synthesized and characterized. A ferrocene-based redox-active ionic liquid is used for referencing the results. All ionic liquids are formed via salt-metathesis from halogenate to bis(trifluoromethylsulfonyl)imide. Their fundamental thermal characteristics are assessed with differential scanning calorimetry. While the imidazolium ionic liquids show no melting point, the phase transition is well observable for the viologen-based ionic liquid. The properties of the neat redox-active ionic liquids and of binary mixtures containing these ionic liquids (0.1 m) and 1-butyl-1-methyl pyrrolidinium-bis(trifluoromethylsulfonyl)imide have been investigated. Finally, the use of these binary mixtures in combination with activated carbon-based electrodes has been considered in view of the use of these redox-active electrolytes in supercapacitors.
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Bhowmik PK, Noori O, Chen SL, Han H, Fisch MR, Robb CM, Variyam A, Martinez-Felipe A. Ionic liquid crystals: Synthesis and characterization via NMR, DSC, POM, X-ray diffraction and ionic conductivity of asymmetric viologen bistriflimide salts. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115370] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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7
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Li S, Safari N, Saielli G, Wang Y. Liquid–Liquid Phase Separation of Viologen Bistriflimide/Benzene Mixtures: Role of the Dual Ionic and Organic Nature of Ionic Liquids. J Phys Chem B 2020; 124:7929-7937. [DOI: 10.1021/acs.jpcb.0c03207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Shen Li
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P.O. Box 2735, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Niloufar Safari
- Department of Chemical Sciences, University of Padova, Via Marzolo, 1, Padova 35131, Italy
| | - Giacomo Saielli
- Department of Chemical Sciences, University of Padova, Via Marzolo, 1, Padova 35131, Italy
- CNR Institute on Membrane Technology, Unit of Padova, Via Marzolo 1, Padova 35131, Italy
| | - Yanting Wang
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P.O. Box 2735, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
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8
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Bhowmik PK, Al-Karawi MKM, Killarney ST, Dizon EJ, Chang A, Kim J, Chen SL, Principe RCG, Ho A, Han H, Mandal HD, Cortez RG, Gutierrez B, Mendez K, Sharpnack L, Agra-Kooijman DM, Fisch MR, Kumar S. Thermotropic Liquid-Crystalline and Light-Emitting Properties of Bis(4-aalkoxyphenyl) Viologen Bis(triflimide) Salts. Molecules 2020; 25:E2435. [PMID: 32456122 PMCID: PMC7288076 DOI: 10.3390/molecules25102435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/21/2020] [Accepted: 05/21/2020] [Indexed: 11/21/2022] Open
Abstract
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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Affiliation(s)
- Pradip K. Bhowmik
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Muhammed Kareem M. Al-Karawi
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Shane T. Killarney
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Erenz J. Dizon
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Anthony Chang
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Jongin Kim
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Si L. Chen
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Ronald Carlo G. Principe
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Andy Ho
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Haesook Han
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA; (M.K.M.A.-K.); (S.T.K.); (E.J.D.); (A.C.); (J.K.); (S.L.C.); (R.C.G.P.); (A.H.); (H.H.)
| | - Hari D. Mandal
- Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA; (H.D.M.); (R.G.C.); (B.G.); (K.M.)
| | - Raymond G. Cortez
- Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA; (H.D.M.); (R.G.C.); (B.G.); (K.M.)
| | - Bryan Gutierrez
- Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA; (H.D.M.); (R.G.C.); (B.G.); (K.M.)
| | - Klarissa Mendez
- Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA; (H.D.M.); (R.G.C.); (B.G.); (K.M.)
| | - Lewis Sharpnack
- Department of Earth Science, 1006 Webb Hall, University of California, Santa Barbara, CA 93106, USA;
| | - Deña M. Agra-Kooijman
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA;
| | - Michael R. Fisch
- College of Aeronautics and Engineering, Kent State University, Kent, OH 44242, USA;
| | - Satyendra Kumar
- Division of Research, University at Albany, Albany, NY 12222, USA;
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9
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The diffusion, structural relaxation, and fragility of [VIO2+][Tf2N−]2 ionic liquid. J Mol Model 2020; 26:55. [DOI: 10.1007/s00894-020-4317-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/31/2020] [Indexed: 10/25/2022]
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10
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Cao W, Senthilkumar B, Causin V, Swamy VP, Wang Y, Saielli G. Influence of the ion size on the stability of the smectic phase of ionic liquid crystals. SOFT MATTER 2020; 16:411-420. [PMID: 31789337 DOI: 10.1039/c9sm02115a] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The thermotropic phase behavior of ionic liquids and ionic liquid crystals based on novel N-alkyl-3-methylpyridinium halides, trihalides and dichloroiodates was experimentally studied by polarized optical spectroscopy (POM) and differential scanning calorimetry (DSC) as well as by molecular dynamics (MD) simulation. In the experiments, the existence and thermal range of stability of the smectic phase of these ionic liquid crystals are found to strongly depend on the volume ratio between the cation and anion, that is their relative size. Only compounds with a relatively large volume ratio of the cation to anion, i.e., those with longer cationic alkyl chains and monoatomic halide anions, have a stable smectic A phase. Both melting points and clearing points increase with such a ratio. The MD simulation results qualitatively agree very well with the experimental data and provide molecular details which can explain the experimentally observed phenomena: the stronger van der Waals interactions from the longer alkyl chains and the stronger electrostatic interactions from the smaller anions with a higher charge density increase the stability of both the crystal phase and the smectic phase; this also prevents the ionic layers from easily mixing with the hydrophobic regions, a mechanism that ultimately leads to a nanosegregated isotropic liquid phase.
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Affiliation(s)
- Wudi Cao
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P. O. Box 2735, Beijing 100190, China.
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11
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Saielli G, Satoh K. A coarse-grained model of ionic liquid crystals: the effect of stoichiometry on the stability of the ionic nematic phase. Phys Chem Chem Phys 2019; 21:20327-20337. [PMID: 31495845 DOI: 10.1039/c9cp03296g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We have investigated, by means of molecular dynamics simulations, the phase behaviour of mixtures of charged ellipsoidal Gay-Berne (GB) particles and spherical Lennard-Jones (LJ) particles, as a coarse-grained model of ionic liquid crystals (ILCs). The anisotropic GB particles represent cations usually found in ILCs, for example, pyridinium or bipyridinium salts, while the spherical LJ particles are taken as a model of anions like common halides, hexafluorophosphate and tetrafluoroborate. Here we have focused our attention on the effect of the stoichiometry of the system (that is, the GB : LJ ratio n : m in the salt formula [GB]n[LJ]m) on the stability and thermal range of the ionic liquid crystal phases formed, with special attention to the ionic nematic phase. To isolate the stoichiometry effect, a comparison of four different systems with GB : LJ ratios of 1 : 3, 1 : 2, 1 : 1 and 2 : 1 is made by keeping the packing fraction and the charge of the minor component fixed. Our results suggest a way to improve the stability of the ionic nematic phase by enhancing the anisotropic van der Waals interaction compared to the Coulomb interaction, and by increasing the proportion of anisotropic particles in the mixture.
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Affiliation(s)
- Giacomo Saielli
- CNR Institute on Membrane Technology, Unit of Padova, Via Marzolo, 1, 35131 Padova, Italy.
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12
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Li S, Wang Y. Percolation Phase Transition from Ionic Liquids to Ionic Liquid Crystals. Sci Rep 2019; 9:13169. [PMID: 31511577 PMCID: PMC6739393 DOI: 10.1038/s41598-019-49493-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 08/27/2019] [Indexed: 11/09/2022] Open
Abstract
Due to their complex molecular structures and interactions, phase behaviors of complex fluids are quite often difficult to be identified by common phase transition analysis methods. Percolation phase transition, on the other hand, only monitors the degree of connection among particles without strict geometric requirements such as translational or orientational order, and thus suitable for pinpointing phase transitions of complex fluids. As typical complex fluids, ionic liquids (ILs) exhibit phases beyond the description of simple liquid theories. In particular, with an intermediate cationic side-chain length, ILs can form the nanoscale segregated liquid (NSL) state, which will eventually transform into the ionic liquid crystal (ILC) structure when the side chains are adequately long. However, the microscopic mechanism of this transformation is still unclear. In this work, by means of coarse-grained molecular dynamics simulation, we show that, with increasing cationic side-chain length, some local pieces of non-polar domains are gradually formed by side chains aligned in parallel inside the NSL phase, before an abrupt percolation phase transition happens when the system transforms into the ILC phase. This work not only identifies that the NSL to ILC phase transition is a critical phenomenon, but also demonstrates the importance of percolation theory to complex fluids.
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Affiliation(s)
- Shen Li
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P. O. Box 2735, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
| | - Yanting Wang
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P. O. Box 2735, Beijing, 100190, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China.
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13
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Di Pietro ME, Margola T, Celebre G, De Luca G, Saielli G. A combined LX-NMR and molecular dynamics investigation of the bulk and local structure of ionic liquid crystals. SOFT MATTER 2019; 15:4486-4497. [PMID: 31093625 DOI: 10.1039/c9sm00612e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The unique power of NMR spectroscopy in anisotropic media (LX-NMR) as a tool to obtain local and bulk structural information, combined with the effectiveness of molecular dynamics simulations at the atomistic level, shows very attractive potentialities for the study of interesting, even though still poorly understood, materials such as Ionic Liquid Crystals (ILCs). In this work, we focused our attention, in particular, on the orientational ordering of two mesophases: 1-dodecyl-3-methylimidazolium chloride, [C12C1im]Cl, and 1-dodecyl-3-methylimidazolium tetrafluoroborate, [C12C1im][BF4]. Both ILCs were studied by a 2H NMR direct investigation of the molecules forming the phases, suitably deuterated, and by 1H NMR spectroscopy, using the small rigid probe-solutes 1,4-dichlorobenzene (DCB), dissolved in [C12C1im][BF4] and [C12C1im]Cl, and 1,4-dibromobenzene (DBB) dissolved in [C12C1im][BF4], to probe the local, internal structure and organization of the mesophases. The experimental results were then compared with the predictions, by atomistic MD simulations, of the structure of the smectic phase of the two salts, at two selected temperatures, containing a single DCB molecule as a probe. The MD simulations show that the DCB solute is distributed only within the hydrophobic layers of the ILC. Orientational order parameters of the imidazolium cations and of the DCB molecule were obtained and compared with the experiments, showing a general good agreement and allowing a deeper understanding of the microscopic structure of the systems.
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Affiliation(s)
- Maria Enrica Di Pietro
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Via P. Bucci, cubo 14C, 87036 Rende, CS, Italy.
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Thermotropic Liquid-Crystalline Properties of Viologens Containing 4-n-alkylbenzenesulfonates. CRYSTALS 2019. [DOI: 10.3390/cryst9020077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A series of viologens containing 4-n-alkylbenzenesulfonates were synthesized by the metathesis reaction of 4-n-alkylbenzenesulfonic acids or sodium 4-n-alkylbezenesulfonates with the respective viologen dibromide in alcohols. Their chemical structures were characterized by Fourier Transform Infrared, 1H and 13C Nuclear Magnetic Resonance spectra and elemental analysis. Their thermotropic liquid-crystalline (LC) properties were examined by differential scanning calorimetry and polarizing optical microscopy. They formed LC phases above their melting transitions and showed isotropic transitions. As expected, all the viologen salts had excellent stabilities in the temperature range of 278–295 °C as determined by thermogravimetric analysis.
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15
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Li S, Saielli G, Wang Y. Aggregation behavior of dihexadecylviologen bistriflimide ionic liquid crystal in different solvents: influence of polarity and concentration. Phys Chem Chem Phys 2018; 20:22730-22738. [PMID: 30137072 DOI: 10.1039/c8cp03055c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solutions of 1,1'-dihexadecyl-4,4'-bipyridinium di[bis(trifluoromethanesulfonyl)imide] salt, also known as dihexadecylviologen bistriflimide, in deuterated acetonitrile (ACN), dichloromethane (DCM) and chloroform (CDCl3), respectively, were investigated by the combination of 1H and DOSY NMR spectroscopy, DFT calculations and MD simulation to understand the influence of solvent polarity and solute concentration (10-5-10-1 M) on its aggregation behavior. We found that the polar solvent acetonitrile (ACN) does not favor ion aggregation and cluster formation. In the whole range of concentrations investigated, the system appears to be dominated by neutral ion pairs composed of one cation and two anions, possibly in fast equilibrium (on the NMR time scale) with small or slightly larger aggregates. The diffusion coefficient of the cationic species is only weakly affected by concentration. In contrast, the low-polar solvents of chloroform (CDCl3) and dichloromethane (DCM) strongly favor cluster formation above a certain concentration and the viologen diffusion coefficient in CDCl3 is much smaller and more strongly dependent on concentration than that in ACN. The information obtained from the MD simulations suggests that the aggregates have a structure similar to the isotropic liquid phase of the viologen-based ionic liquids and ionic liquid crystals. The lifetimes of such large clusters appear to be relatively long, beyond the time scale of tens of nanoseconds. Moreover, the results from the aromatic proton NMR resonances provide some insights on the dielectric constants inside the viologen aggregates.
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Affiliation(s)
- Shen Li
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P. O. Box 2735, Beijing, 100190, China.
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Corrêa CM, Córdoba de Torresi SI, Benedetti TM, Torresi RM. Viologen-functionalized poly(ionic liquids): Spectroelectrochemical and QCM-D studies. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Design of Viologen-Based Liquid Crystals Exhibiting Bicontinuous Cubic Phases and Their Redox-Active Behavior. MATERIALS 2017; 10:ma10111243. [PMID: 29077001 PMCID: PMC5706190 DOI: 10.3390/ma10111243] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 10/25/2017] [Accepted: 10/26/2017] [Indexed: 11/25/2022]
Abstract
We have succeeded in developing viologen-based liquid-crystalline materials forming bicontinuous cubic phases. They are composed of amphiphilic zwitterions with a viologen ionic-head-group and sulfonyl-imide-type acids. In the bicontinuous cubic liquid-crystalline assemblies, the ionic-head groups of the amphiphiles align along a gyroid minimal surface, forming a 3D continuous viologen layer. The ionic state of the viologen-moieties can be tuned from a dication state (V2+) to a radical mono cation state (V1+•) by UV irradiation and/or electric field. This redox reaction proceeds in bulk, accompanying the change of their color from colorless to purple. Interestingly, they preserve the 3D molecular assembled structures beyond the redox reaction, which has been confirmed by polarizing optical microscopy and X-ray diffraction measurements.
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Jordão N, Cruz H, Branco A, Pina F, Branco LC. Bis(bipyridinium) Salts as Multicolored Electrochromic Devices. Chempluschem 2017; 82:1211-1217. [DOI: 10.1002/cplu.201700229] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/24/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Noémi Jordão
- LAQV-REQUIMTE; Departamento de Química; Faculdade de Ciências e Tecnologia; Universidade Nova de Lisboa; 2829-516 Caparica Portugal
| | - Hugo Cruz
- LAQV-REQUIMTE; Departamento de Química; Faculdade de Ciências e Tecnologia; Universidade Nova de Lisboa; 2829-516 Caparica Portugal
| | - Aida Branco
- Ynvisible; Rua Mouzinho de Albuquerque 7 2070-104 Cartaxo Portugal
| | - Fernando Pina
- LAQV-REQUIMTE; Departamento de Química; Faculdade de Ciências e Tecnologia; Universidade Nova de Lisboa; 2829-516 Caparica Portugal
| | - Luís C. Branco
- LAQV-REQUIMTE; Departamento de Química; Faculdade de Ciências e Tecnologia; Universidade Nova de Lisboa; 2829-516 Caparica Portugal
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Saielli G, Margola T, Satoh K. Tuning Coulombic interactions to stabilize nematic and smectic ionic liquid crystal phases in mixtures of charged soft ellipsoids and spheres. SOFT MATTER 2017; 13:5204-5213. [PMID: 28671229 DOI: 10.1039/c7sm00612h] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We have investigated the effect of electrostatic interactions in mixtures of soft ellipsoids and spheres based on the well-known Gay-Berne (GB) and Lennard-Jones (LJ) potential, respectively. These model systems, in their original version, that is without any electrostatic charge, have been thoroughly investigated in the literature both as pure components and mixtures. In particular, mixtures of particles of different shapes, such as spheres and ellipsoids, tend to phase separate because of the excluded volume effects. Common ionic liquid crystals, based on imidazolium or other quaternary ammonium salts, are usually composed of roughly elongated (although flexible) cations and roughly spherical anions, that is, particles with a similar shape such as the GB and LJ models. Therefore, in this work, we present the results of molecular dynamics simulations of mixtures of positively charged GB and negatively charged LJ particles as models of ionic liquid crystals. Interestingly, by modulating the charge of the particles it is possible to stabilize isotropic, nematic, smectic and crystalline ionic phases. The relative weight of Coulomb (a radial, therefore isotropic interaction) and van der Waals (an anisotropic interaction) contributions is a key parameter to tune the stability of various mesophases.
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Affiliation(s)
- Giacomo Saielli
- Istituto per la Tecnologia delle Membrane del CNR (ITM-CNR), Sede Secondaria di Padova, Via Marzolo, 1-35131, Padova, Italy.
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Saielli G, Wang Y. Role of the Electrostatic Interactions in the Stabilization of Ionic Liquid Crystals: Insights from Coarse-Grained MD Simulations of an Imidazolium Model. J Phys Chem B 2016; 120:9152-60. [DOI: 10.1021/acs.jpcb.6b04717] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Giacomo Saielli
- CNR
Institute on Membrane Technology, Unit of Padova and Department of
Chemical Sciences, University of Padova, Via Marzolo, 1-35131 Padova, Italy
| | - Yanting Wang
- CAS
Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P.O.
Box 2735, Beijing, 100190, China
- School
of Physical Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
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Ramírez-González PE, Ren G, Saielli G, Wang Y. Effect of Ion Rigidity on Physical Properties of Ionic Liquids Studied by Molecular Dynamics Simulation. J Phys Chem B 2016; 120:5678-90. [DOI: 10.1021/acs.jpcb.6b03379] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pedro E. Ramírez-González
- CAS
Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P.O.
Box 2735, Beijing 100190, China
| | - Gan Ren
- CAS
Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P.O.
Box 2735, Beijing 100190, China
| | - Giacomo Saielli
- Istituto per la
Tecnologia delle Membrane del CNR, Sezione di Padova, Via Marzolo, 1, 35131 Padova, Italy
| | - Yanting Wang
- CAS
Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 55 East Zhongguancun Road, P.O.
Box 2735, Beijing 100190, China
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Alvarez Fernandez A, Kouwer PHJ. Key Developments in Ionic Liquid Crystals. Int J Mol Sci 2016; 17:E731. [PMID: 27196890 PMCID: PMC4881553 DOI: 10.3390/ijms17050731] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 11/25/2022] Open
Abstract
Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?
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Affiliation(s)
- Alexandra Alvarez Fernandez
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
- School of Materials Science and Engineering, Nanyang Technological University, Blk N4.1 Nanyang Avenue, Singapore 639798, Singapore.
| | - Paul H J Kouwer
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
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Goossens K, Lava K, Bielawski CW, Binnemans K. Ionic Liquid Crystals: Versatile Materials. Chem Rev 2016; 116:4643-807. [PMID: 27088310 DOI: 10.1021/cr400334b] [Citation(s) in RCA: 411] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This Review covers the recent developments (2005-2015) in the design, synthesis, characterization, and application of thermotropic ionic liquid crystals. It was designed to give a comprehensive overview of the "state-of-the-art" in the field. The discussion is focused on low molar mass and dendrimeric thermotropic ionic mesogens, as well as selected metal-containing compounds (metallomesogens), but some references to polymeric and/or lyotropic ionic liquid crystals and particularly to ionic liquids will also be provided. Although zwitterionic and mesoionic mesogens are also treated to some extent, emphasis will be directed toward liquid-crystalline materials consisting of organic cations and organic/inorganic anions that are not covalently bound but interact via electrostatic and other noncovalent interactions.
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Affiliation(s)
- Karel Goossens
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS) , Ulsan 689-798, Republic of Korea.,Department of Chemistry, KU Leuven , Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium
| | - Kathleen Lava
- Department of Chemistry, KU Leuven , Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium.,Department of Organic and Macromolecular Chemistry, Ghent University , Krijgslaan 281 S4, B-9000 Ghent, Belgium
| | - Christopher W Bielawski
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS) , Ulsan 689-798, Republic of Korea.,Department of Chemistry and Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, Republic of Korea
| | - Koen Binnemans
- Department of Chemistry, KU Leuven , Celestijnenlaan 200F, P.O. Box 2404, B-3001 Heverlee, Belgium
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Saielli G. Fully Atomistic Simulations of the Ionic Liquid Crystal [C16mim][NO3]: Orientational Order Parameters and Voids Distribution. J Phys Chem B 2016; 120:2569-77. [DOI: 10.1021/acs.jpcb.5b12469] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Giacomo Saielli
- CNR Institute
on Membrane
Technology and Department of Chemical Sciences, University of Padova, Via Marzolo, 1, 35131 Padova, Italy
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Self-assembly of amphiphilic linear diblock rod-coil molecules by hydrogen bond and π-π stacking interactions. CHINESE JOURNAL OF POLYMER SCIENCE 2016. [DOI: 10.1007/s10118-016-1755-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Wuckert E, Harjung MD, Kapernaum N, Mueller C, Frey W, Baro A, Giesselmann F, Laschat S. Photoresponsive ionic liquid crystals based on azobenzene guanidinium salts. Phys Chem Chem Phys 2015; 17:8382-92. [DOI: 10.1039/c4cp04783d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The mesomorphic properties and the kinetics of the E/Z-photoisomerization in an ILC matrix of new azobenzene ILCs were investigated.
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Affiliation(s)
- Eugen Wuckert
- Institut für Organische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
| | - Marc D. Harjung
- Institut für Physikalische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
| | - Nadia Kapernaum
- Institut für Physikalische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
| | - Carsten Mueller
- Institut für Physikalische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
| | - Wolfgang Frey
- Institut für Organische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
| | - Angelika Baro
- Institut für Organische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
| | - Frank Giesselmann
- Institut für Physikalische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
| | - Sabine Laschat
- Institut für Organische Chemie
- Universität Stuttgart
- D-70569 Stuttgart
- Germany
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Jordão N, Cruz H, Branco A, Pinheiro C, Pina F, Branco LC. Switchable electrochromic devices based on disubstituted bipyridinium derivatives. RSC Adv 2015. [DOI: 10.1039/c5ra02368h] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Gel switchable electrochromic devices based on disubstituted bipyridinium derivatives have been developed.
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Affiliation(s)
- Noémi Jordão
- REQUIMTE
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade Nova de Lisboa
- 2829-516 Monte de Caparica
| | - Hugo Cruz
- REQUIMTE
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade Nova de Lisboa
- 2829-516 Monte de Caparica
| | | | | | - Fernando Pina
- REQUIMTE
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade Nova de Lisboa
- 2829-516 Monte de Caparica
| | - Luís C. Branco
- REQUIMTE
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade Nova de Lisboa
- 2829-516 Monte de Caparica
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Cospito S, Beneduci A, Veltri L, Salamonczyk M, Chidichimo G. Mesomorphism and electrochemistry of thienoviologen liquid crystals. Phys Chem Chem Phys 2015; 17:17670-8. [DOI: 10.1039/c5cp02350e] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New π-conjugated ionic liquid crystals with a strong electron-acceptor thienoviologen core are potentially exploitable as electroactive materials in organic electronics.
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Affiliation(s)
- S. Cospito
- Department of Chemistry and Chemical Technologies
- University of Calabria
- Arcavacata di Rende (CS) 87036
- Italy
- Institute of Chemistry
| | - A. Beneduci
- Department of Chemistry and Chemical Technologies
- University of Calabria
- Arcavacata di Rende (CS) 87036
- Italy
| | - L. Veltri
- Department of Chemistry and Chemical Technologies
- University of Calabria
- Arcavacata di Rende (CS) 87036
- Italy
| | - M. Salamonczyk
- Faculty of Chemistry
- University of Warsaw
- 02-089 Warsaw
- Poland
| | - G. Chidichimo
- Department of Chemistry and Chemical Technologies
- University of Calabria
- Arcavacata di Rende (CS) 87036
- Italy
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Lan X, Bai L, Li X, Ma S, He X, Meng F. Cholesteryl-containing ionic liquid crystals composed of alkylimidazolium cations and different anions. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.07.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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