1
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Guschlbauer J, Niedzicki L, Jacob L, Rzeszotarska E, Pociecha D, Kaszyński P. Liquid Crystalline Electrolytes Derived from the 1,12-Disubstituted [closo-CB11H12]– Anion. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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2
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Schilling C, Bauer A, Knöller JA, Schulz F, Zens A, Laschat S. Tailoring boron liquid crystals: Mesomorphic properties of iminodiacetic acid boronates. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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3
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Shmal'ko AV, Cendoya P, Anufriev SA, Suponitsky KY, Gabel D, Sivaev IB. New approaches to the functionalization of the 1-carba- closo-decaborate anion. Chem Commun (Camb) 2022; 58:3775-3778. [PMID: 35234218 DOI: 10.1039/d1cc06395b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Two new approaches to the functionalization of the 1-carba-closo-decaborate anion [1-CB9H10]- at boron atoms via the ring-opening of its 1,4-dioxane derivative with various nucleophiles and Pd-catalysed cross-coupling of its iodo derivative with aromatic amines and heteroaromatics were developed.
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Affiliation(s)
- Akim V Shmal'ko
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Str, Moscow, 119991, Russia. .,Department of Life Sciences and Chemistry, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany
| | - Paula Cendoya
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany
| | - Sergey A Anufriev
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Str, Moscow, 119991, Russia.
| | - Kyrill Yu Suponitsky
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Str, Moscow, 119991, Russia.
| | - Detlef Gabel
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany
| | - Igor B Sivaev
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Str, Moscow, 119991, Russia.
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4
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Transition metal catalyzed synthesis of derivatives of polyhedral boron hydrides with B N, B P, B O and B S bonds. ADVANCES IN CATALYSIS 2022. [DOI: 10.1016/bs.acat.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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5
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Kubasov AS, Turyshev ES, Novikov IV, Gurova OM, Starodubets PA, Golubev AV, Zhizhin KY, Kuznetsov NT. Theoretical and experimental comparison of the reactivity of the sulfanyl-closo-decaborate and sulfanyl-closo-dodecaborate anions and their mono-S-substituted derivatives. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115347] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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6
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Jakubowski R, Pietrzak A, Friedli AC, Kaszyński P. C(1)-Phenethyl Derivatives of [closo-1-CB 11 H 12 ] - and [closo-1-CB 9 H 10 ] - Anions: Difunctional Building Blocks for Molecular Materials. Chemistry 2020; 26:17481-17494. [PMID: 32776629 DOI: 10.1002/chem.202002997] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Indexed: 11/07/2022]
Abstract
C(1)-vinylation of [closo-1-CB9 H10 ]- (A) and [closo-1-CB11 H12 ]- (B) with 4-benzyloxystyryl iodide followed by hydrogenation of the double bond and reductive deprotection of the phenol functionality led to C(1)-(4-hydroxyphenethyl) derivatives. The phenol functionality was protected as the acetate. The esters were then treated with PhI(OAc)2 and the resulting isomers were separated kinetically (for derivatives of anion A) or by chromatography (for derivatives of anion B) giving the difunctionalized building blocks in overall yields of 9 % and 50 %, respectively. A similar series of reactions was performed starting with anions A and B and 4-methoxystyryl bromide and iodide. Significant differences in the reactivity of derivatives of the two carborane anions were rationalized with DFT computational results. Application of the difunctionalized carboranes as building blocks was demonstrated through preparation of two ionic liquid crystals. The extensive synthetic work is accompanied by single crystal XRD analysis of six derivatives.
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Affiliation(s)
- Rafał Jakubowski
- Centre of Molecular and Macromolecular Studies, Polish Academy of, Sciences, Sienkiewicza 112, 90-363, Łódź, Poland.,Department of Chemistry, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | - Anna Pietrzak
- Department of Chemistry, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.,Faculty of Chemistry, Łódź University of Technology, Żeromskiego 116, 90-924, Łódź, Poland
| | - Andrienne C Friedli
- Department of Chemistry, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | - Piotr Kaszyński
- Centre of Molecular and Macromolecular Studies, Polish Academy of, Sciences, Sienkiewicza 112, 90-363, Łódź, Poland.,Department of Chemistry, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.,Faculty of Chemistry, University of Łódź, Tamka 12, 91-403, Łódź, Poland
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7
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Shmal’ko AV, Sivaev IB. Chemistry of Carba-closo-decaborate Anions [CB9H10]– (Review). RUSS J INORG CHEM+ 2020. [DOI: 10.1134/s0036023619140067] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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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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9
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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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10
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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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11
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Dziedzic RM, Spokoyny AM. Metal-catalyzed cross-coupling chemistry with polyhedral boranes. Chem Commun (Camb) 2019; 55:430-442. [PMID: 30525176 PMCID: PMC6491218 DOI: 10.1039/c8cc08693a] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over the past several decades, metal-catalyzed cross-coupling has emerged as a very powerful strategy to functionalize carbon-based molecules. More recently, some of the cross-coupling methodologies have been adapted to inorganic compounds including boron-rich clusters. The development of this chemistry relies on the ability to synthesize halogenated boron-rich clusters which can serve as electrophilic cross-coupling partners with nucleophilic substrates in the presence of a metal catalyst. While the cross-coupling chemistry with boron-clusters is conceptually reminiscent of that of its hydrocarbon counterparts, several key aspects including the spheroidal bulk of clusters and the distinct nature of boron-halogen/boron-heteroatom bonds make this chemistry unique. The utility of metal-catalyzed cross-coupling can be extended to several classes of polyhedral boranes including neutral and anionic carboranes, metallaboranes, and carbon-free boranes. Importantly, cross-coupling enables a suite of boron-heteroatom (C, N, O, P, S) couplings to prepare boron cluster-based systems that can be used for ligand design, medicinal chemistry, and materials applications.
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Affiliation(s)
- Rafal M Dziedzic
- Department of Chemistry & Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, USA.
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12
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Żurawiński R, Jakubowski R, Domagała S, Kaszyński P, Woźniak K. Regioselective Functionalization of the [ closo-1-CB 9H 10] - Anion through Iodonium Zwitterions. Inorg Chem 2018; 57:10442-10456. [PMID: 30067341 DOI: 10.1021/acs.inorgchem.8b01701] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reactions of [ closo-1-CB9H9-1-R]- (2, R = H, COOH, C5H11) with PhI(OAc)2 lead to mixtures of regioisomers [ closo-1-CB9H8-1-R-6-IPh] (5[6]) and [ closo-1-CB9H8-1-R-10-IPh] (5[10]) in ratios of ∼3:1 to 1:1, of which the former isomer undergoes selective reactions with nucleophiles (MeCN, pyridine, MeC(═NH)NH2, CN-). The products and the unreacted 10-isomers 5[10] are separated achieving kinetic resolution of the isomeric iodonium zwitterions. Pure 5[10] is reacted with nucleophiles (pyridine, 4-C7H15OPyridine, Me2NCHS, PhCO2-, CN-, N3-, I-, MeC(═NH)NH2, and MeCN), giving substitution products. The mechanism of the substitution is investigated with density functional theory (DFT) methods. Some of the nucleophilic substitution products are transformed further, expanding the scope of available functional groups for the [ closo-1-CB9H10]- anion. Four derivatives are characterized with single-crystal XRD methods: [ closo-1-CB9H9-10-N2] (4[10]a), [ closo-1-CB9H9-6-NC5H5] (9[6]a), [ closo-1-CB9H9-10-NC5H5] (9[10]a), and [ closo-1-CB9H9-10-NHC(NH2)Me] (10[10]a). Spectroscopic data for selected derivatives are interpreted in terms of transmission of electronic effects through the { closo-1-CB9} cluster (NMR) and interaction with substituents (IR, UV). The latter results are compared to those of TD-DFT computational methods.
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Affiliation(s)
- Remigiusz Żurawiński
- Centre of Molecular and Macromolecular Studies , Polish Academy of Sciences , 90-363 Łódź , Poland.,Department of Chemistry , Middle Tennessee State University , Murfreesboro , Tennessee 37130 , United States
| | - Rafał Jakubowski
- Centre of Molecular and Macromolecular Studies , Polish Academy of Sciences , 90-363 Łódź , Poland.,Department of Chemistry , Middle Tennessee State University , Murfreesboro , Tennessee 37130 , United States
| | - Sławomir Domagała
- Department of Chemistry , University of Warsaw , 02-089 Warsaw , Poland
| | - Piotr Kaszyński
- Centre of Molecular and Macromolecular Studies , Polish Academy of Sciences , 90-363 Łódź , Poland.,Department of Chemistry , Middle Tennessee State University , Murfreesboro , Tennessee 37130 , United States.,Faculty of Chemistry , University of Łódź , 91-403 Łódź , Poland
| | - Krzysztof Woźniak
- Department of Chemistry , University of Warsaw , 02-089 Warsaw , Poland
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13
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Cook AR, Valášek M, Funston AM, Poliakov P, Michl J, Miller JR. p-Carborane Conjugation in Radical Anions of Cage–Cage and Cage–Phenyl Compounds. J Phys Chem A 2018; 122:798-810. [DOI: 10.1021/acs.jpca.7b10885] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew R. Cook
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Michal Valášek
- Institute
of Organic Chemistry and Biochemistry, ASCR, Prague 6 16610, Czech Republic
| | - Alison M. Funston
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Pavel Poliakov
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Josef Michl
- Institute
of Organic Chemistry and Biochemistry, ASCR, Prague 6 16610, Czech Republic
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - John R. Miller
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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14
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Liang X, Shen Y, Zhang K, Liu J, Duttwyler S. Rhodium(iii)-catalyzed dehydrogenative dialkenylation of the monocarba-closo-decaborate cluster by regioselective B–H activation. Chem Commun (Camb) 2018; 54:12451-12454. [DOI: 10.1039/c8cc05983g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The regioselective double B–H activation of the {CB9} carborane by rhodium catalysis is reported, affording novel inorganic–organic hybrid clusters.
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Affiliation(s)
- Xuewei Liang
- Department of Chemistry
- Zhejiang University
- 310027 Hangzhou
- P. R. China
| | - Yunjun Shen
- Department of Chemistry
- Zhejiang University
- 310027 Hangzhou
- P. R. China
| | - Kang Zhang
- Department of Chemistry
- Zhejiang University
- 310027 Hangzhou
- P. R. China
| | - Jiyong Liu
- Department of Chemistry
- Zhejiang University
- 310027 Hangzhou
- P. R. China
| | - Simon Duttwyler
- Department of Chemistry
- Zhejiang University
- 310027 Hangzhou
- P. R. China
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15
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Rzeszotarska E, Novozhilova I, Kaszyński P. Convenient Synthesis of [closo-B10H9-1-I]2– and [closo-B10H8-1,10-I2]2– Anions. Inorg Chem 2017; 56:14351-14356. [DOI: 10.1021/acs.inorgchem.7b02477] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Edyta Rzeszotarska
- Centre of Molecular
and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza
112, 90363 Łódź, Poland
| | - Irina Novozhilova
- Organic Materials Research Group, Department
of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
| | - Piotr Kaszyński
- Centre of Molecular
and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza
112, 90363 Łódź, Poland
- Organic Materials Research Group, Department
of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
- Faculty of Chemistry, University of Łódź, Tamka 12, 91403 Łódź, Poland
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16
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Wöhrle T, Gündemir R, Frey W, Knecht F, Köhn A, Laschat S. Thermotropic MIDA Boronates as a Case Study for the Role of Dipolar Interactions in Liquid Crystalline Self-Assembly. Chemistry 2017; 23:4149-4159. [DOI: 10.1002/chem.201605648] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Indexed: 01/12/2023]
Affiliation(s)
- Tobias Wöhrle
- Institut für Organische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Rafet Gündemir
- Institut für Organische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Wolfgang Frey
- Institut für Organische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Friederike Knecht
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Andreas Köhn
- Institut für Theoretische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Sabine Laschat
- Institut für Organische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
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17
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Li HH, Bai F, Yan H, Lu CS. Base-Promoted Decarboxylative Azo-Coupling: Construction of Unsymmetrical Azocarboranes. Org Lett 2017; 19:862-865. [DOI: 10.1021/acs.orglett.7b00013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Huan-huan Li
- State
Key Laboratory of Coordination Chemistry, School of Chemistry and
Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023 (P. R. China)
| | - Fan Bai
- State
Key Laboratory of Coordination Chemistry, School of Chemistry and
Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023 (P. R. China)
| | - Hong Yan
- State
Key Laboratory of Coordination Chemistry, School of Chemistry and
Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023 (P. R. China)
| | - Chang-sheng Lu
- State
Key Laboratory of Coordination Chemistry, School of Chemistry and
Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023 (P. R. China)
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18
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Saccone M, Palacio FF, Cavallo G, Dichiarante V, Virkki M, Terraneo G, Priimagi A, Metrangolo P. Photoresponsive ionic liquid crystals assembled via halogen bond: en route towards light-controllable ion transporters. Faraday Discuss 2017; 203:407-422. [DOI: 10.1039/c7fd00120g] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We demonstrate that halogen bonding (XB) can offer a novel approach for the construction of photoresponsive ionic liquid crystals. In particular, we assembled two new supramolecular complexes based on 1-ethyl-3-methylimidazolium iodides and azobenzene derivatives containing an iodotetrafluoro-benzene ring as XB donor, where the iodide anion acted as an XB acceptor. DSC and X-ray diffraction analyses revealed that the preferred stoichiometry between the XB donors and acceptors is 2 : 1, and that the iodide anions act as bidentate XB-acceptors, binding two azobenzene derivatives. Due to the high directionality of the XB, calamitic superanions are obtained, while the segregation occurring between the charged and uncharged parts of the molecules gives rise to a layered structure in the crystal lattice. Despite the fact that the starting materials are non-mesomorphic, the halogen-bonded supramolecular complexes exhibited monotropic lamellar liquid-crystalline phases over broad temperature ranges, as confirmed with polarized optical microscopy. Due to the presence of the azobenzene moieties, the LCs were photoresponsive, and a LC-to-isotropic phase transition could be obtained by irradiation with UV light. We envisage that the light-induced phase transition, in combination with the ionic nature of the LC, provides a route towards light-induced control over ion transport and conductance in these supramolecular complexes.
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Affiliation(s)
- Marco Saccone
- Laboratory of Chemistry and Bioengineering
- Tampere University of Technology
- FI-33101 Tampere
- Finland
| | - Francisco Fernandez Palacio
- Supramolecular & BioNano Materials Laboratory (SupraBioNanoLab)
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
- Italy
| | - Gabriella Cavallo
- Supramolecular & BioNano Materials Laboratory (SupraBioNanoLab)
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
- Italy
| | - Valentina Dichiarante
- Supramolecular & BioNano Materials Laboratory (SupraBioNanoLab)
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
- Italy
| | - Matti Virkki
- Laboratory of Chemistry and Bioengineering
- Tampere University of Technology
- FI-33101 Tampere
- Finland
| | - Giancarlo Terraneo
- Supramolecular & BioNano Materials Laboratory (SupraBioNanoLab)
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
- Italy
| | - Arri Priimagi
- Laboratory of Chemistry and Bioengineering
- Tampere University of Technology
- FI-33101 Tampere
- Finland
| | - Pierangelo Metrangolo
- Supramolecular & BioNano Materials Laboratory (SupraBioNanoLab)
- Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
- Italy
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19
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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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20
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Pecyna J, Kaszyński P, Ringstrand B, Pociecha D, Pakhomov S, Douglass AG, Young VG. Synthesis and Characterization of Quinuclidinium Derivatives of the [closo-1-CB11H12]− Anion as Potential Polar Components of Liquid Crystal Materials. Inorg Chem 2016; 55:4016-25. [PMID: 27018818 DOI: 10.1021/acs.inorgchem.6b00319] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jacek Pecyna
- Organic Materials Research Group, Department
of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
| | - Piotr Kaszyński
- Organic Materials Research Group, Department
of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
- Center of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90363 Łódź, Poland
- Faculty of Chemistry, University of Łódź, Tamka 12, 91403 Łódź, Poland
| | | | - Damian Pociecha
- Department of Chemistry, University of Warsaw, Zwirki i Wigury
101, 02089 Warsaw, Poland
| | | | - Andrew G. Douglass
- Organic Materials Research Group, Department
of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
| | - Victor G. Young
- X-ray Crystallographic Laboratory, Department
of Chemistry, University of Minnesota, Twin Cities, Minnesota 55455, United States
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21
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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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22
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Jankowiak A, Sivaramamoorthy A, Pociecha D, Kaszyński P. How much do coulombic interactions stabilize a mesophase? Ion pair and non-ionic binary isosteric derivatives of monocarbaborates and carboranes. RSC Adv 2014. [DOI: 10.1039/c4ra06502f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A comparison of two isosteric, ionic and non-ionic binary systems, provides a measure of coulombic interactions impact on mesophase stability in the absence of other factors.
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Affiliation(s)
| | | | - Damian Pociecha
- Department of Chemistry
- University of Warsaw
- 02-089 Warsaw, Poland
| | - Piotr Kaszyński
- Department of Chemistry
- Vanderbilt University
- Nashville, USA
- Faculty of Chemistry
- University of Łódź
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23
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24
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Ringstrand B. Boron clusters as structural elements of novel liquid crystalline materials. LIQUID CRYSTALS TODAY 2013. [DOI: 10.1080/1358314x.2013.829932] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Ringstrand B, Kaszynski P. Functionalization of the [closo-1-CB9H10]- anion for the construction of new classes of liquid crystals. Acc Chem Res 2013; 46:214-25. [PMID: 23098274 DOI: 10.1021/ar300081b] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The [closo-1-CB(9)H(10)](-) anion is a member of an extensive family of σ-aromatic closo-boranes that possess impressive stability and functionalization characteristics. In contrast to its bigger, more extensively studied brother, the [closo-1-CB(11)H(12)](-) anion, convenient access to the [closo-1-CB(9)H(10)](-) anion has only been recently established, and researchers have only begun to develop and understand its fundamental chemistry. The geometrical and electronic properties of the [closo-1-CB(9)H(10)](-) anion make it an attractive structural element of novel classes of either zwitterionic or ionic liquid crystals suitable for electro-optical and ion transport applications, respectively. Such materials require a 1,10-difunctionalized [closo-1-CB(9)H(10)](-) anion that permits for the formation of molecules of elongated shape. The covalent attachment of an onium fragment or the use of a counterion compensates for the negative charge. This Account highlights the progress made in the advancement and understanding of the fundamental chemistry of the [closo-1-CB(9)H(10)](-) anion. We also describe the development of 1,10-difunctionalized derivatives as key intermediates in the preparation of new classes of liquid crystalline materials. We obtained the first isomerically pure 1,10-difunctionalized derivative of the [closo-1-CB(9)H(10)](-) anion, iodo acid [closo-1-CB(9)H(8)-1-COOH-10-I](-), from decaborane through the Brellochs reaction. Functional group transformation of the C(1)-carboxyl group led to a 1-amino derivative and, subsequently, to a synthetically valuable 1-dinitrogen derivative. The latter exhibits reactivity typical for PhN(2)(+) and undergoes diazocoupling and Gomberg-Bachmann arylation reactions. The B(10)-iodine participated in Negishi alkylation and Buchwald-Hartwig amination reactions, leading to 10-hexyl and 10-amino carboxylic acids, respectively. We converted the 10-amino carboxylic acid to a 10-dinitrogen acid [closo-1-CB(9)H(8)-1-COOH-10-N(2)], which proved to be synthetically valuable in the preparation of 10-pyridinium and 10-sulfonium zwitterionic acids and their liquid crystalline esters. We investigated several intermediates using structural, spectroscopic, and kinetic methods.
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Affiliation(s)
- Bryan Ringstrand
- Organic Materials Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Piotr Kaszynski
- Organic Materials Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Faculty of Chemistry, University of Łódź, Tamka 12, 91403 Łódź, Poland
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26
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Tao J, Zhong J, Liu P, Daniels S, Zeng Z. Pyridinium-based ionic liquid crystals with terminal fluorinated pyrrolidine. J Fluor Chem 2012. [DOI: 10.1016/j.jfluchem.2012.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Pecyna JG, Ringstrand B, Kaszyński P. Transmission of Electronic Effects through the {closo-1-CB9} and {closo-1-CB11} Cages: Apparent Dissociation Constants for Series of [closo-1-CB9H8-1-COOH-10-X] and [closo-1-CB11H10-1-COOH-12-X] Acids. Inorg Chem 2012; 51:5353-9. [DOI: 10.1021/ic300298e] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Jacek G. Pecyna
- Organic Materials
Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee
37235,
United States
| | - Bryan Ringstrand
- Organic Materials
Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee
37235,
United States
| | - Piotr Kaszyński
- Organic Materials
Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee
37235,
United States
- Faculty of Chemistry, University of Lódź, Tamka 12, 91403 Lódź,
Poland
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28
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Butschies M, Frey W, Laschat S. Designer Ionic Liquid Crystals Based on Congruently Shaped Guanidinium Sulfonates. Chemistry 2012; 18:3014-22. [DOI: 10.1002/chem.201101925] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/27/2011] [Indexed: 11/05/2022]
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29
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Ringstrand B, Jankowiak A, Johnson LE, Kaszynski P, Pociecha D, Górecka E. Anion-driven mesogenicity: a comparative study of ionic liquid crystals based on the [closo-1-CB9H10]− and [closo-1-CB11H12]− clusters. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm15448j] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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The preparation of [closo-1-CB9H8-1-COOH-10-(4-C3H7C5H9S)] as intermediate to polar liquid crystals. Polyhedron 2011. [DOI: 10.1016/j.poly.2011.06.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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31
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Zhang J, Zhou M, Wang S, Carr J, Li W, Wu L. Thermotropic organization of hydrogen-bond-bridged bolaform amphiphiles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4134-4141. [PMID: 21361358 DOI: 10.1021/la2000574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A series of quaternary ammonium amphiphiles (A-n) bearing carboxylic acid groups were designed and synthesized. The branched bolaform structures can be constructed by dimerizations of carboxylic acid groups through intermolecular hydrogen bonding, as demonstrated by the Fourier transform infrared (FT-IR) spectra and the temperature-dependent FT-IR spectra. The thermotropic organizations of branched bolaform ammonium dimer complexes were characterized by differential scanning calorimetry, polarized optical microscopy, and X-ray diffraction. We investigated the influence of the spacer between the cationic group and the benzene ring on the thermotropic organization. A-6 with short lateral alkyl chains formed a simple layered structure at room temperature and exhibited smectic A mesophase above 145 °C, whereas A-8 with intermediate lateral chain length organized into smectic A phase over a wide temperature range. A further increase of the length (n = 10, 12) of the lateral chains resulted in the formation of lamellar structure with in-plane layered periodicity, which is rare in the organization of ionic compounds. A packing model of the quasi-2D lamellar was proposed on the basis of the experimental data of X-ray diffraction results. Notably, the quasi-2D lamellar structure could evolve into a simple layer with the increase of temperature. The present results showed a direct relationship in which the branched architecture can be applied to tune the self-assembly behavior of ionic amphiphiles and is allowed to construct new layered superstructure.
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Affiliation(s)
- Jing Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
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32
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Axenov KV, Laschat S. Thermotropic Ionic Liquid Crystals. MATERIALS 2011; 4:206-259. [PMID: 28879986 PMCID: PMC5448481 DOI: 10.3390/ma4010206] [Citation(s) in RCA: 273] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 12/27/2010] [Indexed: 12/26/2022]
Abstract
The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.
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Affiliation(s)
- Kirill V Axenov
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
| | - Sabine Laschat
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
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33
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Ringstrand B, Kaszynski P, Young VG, Janousek Z. Anionic amino acid [closo-1-CB9H8-1-COO-10-NH3]- and dinitrogen acid [closo-1-CB9H8-1-COOH-10-N2] as key precursors to advanced materials: synthesis and reactivity. Inorg Chem 2010; 49:1166-79. [PMID: 20043626 DOI: 10.1021/ic9021323] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Amino acid [closo-1-CB(9)H(8)-1-COO-10-NH(3)](-) (4) was prepared by amination of iodo acid [closo-1-CB(9)H(8)-1-COOH-10-I](-) (1) with LiHMDS in a practical and reproducible manner. The apparent dissociation constants, pK(2) = 5.6 and pK(1) > 11, were measured for 4[NMe(4)] in 50% aq. EtOH. Diazotization of 4 with NO(+)PF(6)(-) under mildly basic conditions afforded stable dinitrogen acid [closo-1-CB(9)H(8)-1-COOH-10-N(2)] (5). Activation parameters (DeltaH(++) = 33.9 +/- 1.4 kcal mol(-1) and DeltaS(++) = 10 +/- 3.5 cal mol(-1) K(-1)) for thermolysis of its methyl ester [closo-1-CB(9)H(8)-1-COOMe-10-N(2)] (11) in PhCN were established, and the heterolysis of the B-N bond is believed to be the rate-determining step. Electrochemical analysis showed a partially reversible reduction process for 11 (E(1/2)(red) = -1.03 V) and 5(-) (E(1/2)(red) = -1.21 V), which are more cathodic than reduction of [closo-1-CB(9)H(9)-1-N(2)] (17). The dinitrogen acid 5 was reacted with pyridine and N,N-dimethylthioformamide, to form pyridine acid 6 and protected mercapto acid 7, respectively, through a boronium ylide intermediate 18. Compound 7 was converted to sulfonium acid 8. The molecular and crystal structures for 5 [C(2)H(9)B(9)N(2)O(2) monoclinic, P2(1)/n, a = 7.022(2) A, b = 11.389(4) A, c = 12.815(4) A, beta = 96.212(5) degrees ; V = 1018.8(6) A(3), Z = 4,], 6 [C(7)H(14)B(9)NO(2), monoclinic, P2(1)/n, a = 14.275(4) A, b = 12.184(3) A, c = 30.538(8) A, beta = 95.377(4) degrees ; V = 5288(3) A(3), Z = 16], and 8 [C(7)H(19)B(9)O(2)S, monoclinic, P2(1)/c, a = 15.988(5) A, b = 19.377(6) A, c = 9.655(3) A, beta = 98.348(5) degrees; V = 2959.4(16) A(3), Z = 8] were determined by X-ray crystallography and compared with results of density functional theory (DFT) and MP2 calculations. Electronic structures of 5, 6, and related species were elucidated with electronic spectroscopy and assessed computationally at the B3LYP/6-31G(d,p), MP2/6-31G(d,p), and ZINDO//MP2 levels of theory.
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Affiliation(s)
- Bryan Ringstrand
- Organic Materials Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA
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34
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Wiggins KM, Kerr RL, Chen Z, Bielawski CW. Retracted article: Design, synthesis, and study of benzobis- and bibenz(imidazolium)-based ionic liquid crystals. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/c0jm00417k] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Ringstrand B, Kaszynski P, Franken A. Synthesis and Reactivity of [closo-1-CB9H9-1-N2]: Functional Group Interconversion at the Carbon Vertex of the {closo-1-CB9} Cluster. Inorg Chem 2009; 48:7313-29. [DOI: 10.1021/ic9007476] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bryan Ringstrand
- Organic Materials Research Group Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Piotr Kaszynski
- Organic Materials Research Group Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Andreas Franken
- Organic Materials Research Group Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
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36
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Ringstrand B, Kaszynski P, Januszko A, Young VG. Polar derivatives of the [closo-1-CB9H10]− cluster as positive Δε additives to nematic hosts. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b913701g] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Causin V, Saielli G. Effect of asymmetric substitution on the mesomorphic behaviour of low-melting viologen salts of bis(trifluoromethanesulfonyl)amide. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b915559g] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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