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Kwon O, Cai X, Saeed A, Liu F, Poppe S, Tschierske C. 2,6-Dibromogallates as a new building block for controlling π-stacking, network formation and mirror symmetry breaking. Chem Commun (Camb) 2021; 57:6491-6494. [PMID: 34100483 DOI: 10.1039/d1cc01922h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Achiral multi-chain (polycatenar) compounds based on the 2,7-diphenyl substituted [1]benzothieno[3,2-b]benzothiophene (BTBT) unit and a 2,6-dibromo-3,4,5-trialkoxybenzoate end group lead to materials forming bicontinuous cubic liquid crystalline phases with helical network structures over wide temperature ranges.
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Affiliation(s)
- Ohjin Kwon
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, 06120 Halle (Saale), Germany.
| | - Xiaoqian Cai
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
| | - Azhar Saeed
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
| | - Feng Liu
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
| | - Silvio Poppe
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, 06120 Halle (Saale), Germany.
| | - Carsten Tschierske
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, 06120 Halle (Saale), Germany.
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Alaasar M, Schmidt JC, Cai X, Liu F, Tschierske C. Controlling liquid and liquid crystalline network formation by core-fluorination of hydrogen bonded supramolecular polycatenars. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115870] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Liquid Crystals Based on the N-Phenylpyridinium Cation-Mesomorphism and the Effect of the Anion. Molecules 2021; 26:molecules26092653. [PMID: 34062725 PMCID: PMC8124330 DOI: 10.3390/molecules26092653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
Families of symmetric, ionic, tetracatenar mesogens are described based on a rigid, N-phenylpyridinium core, prepared as their triflimide, octyl sulfate and dodecyl sulfate salts for a range of terminal chain lengths. The mesomorphism of the individual series is described before a comparison is drawn between the different families and then more broadly with (i) neutral tetracatenar materials and (ii) related bis(3,4-dialkoxystilbazole)silver(I) salts. For the octyl and dodecyl sulfates and the related triflates reported earlier, a SmA phase is seen at shorter chain lengths, giving way to a Colh phase as the terminal chain lengthens. For the alkyl sulfate salts, an intermediate cubic phase is also seen and the terminal chain length required to cause the change from lamellar to columnar mesophase depends on the anion. Furthermore, there is an unexpected and sometime very large mesophase stabilisation seen on entering the columnar phase. All of the triflimide salts show a rectangular columnar (ribbon) phase.
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Reppe T, Poppe S, Tschierske C. Controlling Mirror Symmetry Breaking and Network Formation in Liquid Crystalline Cubic, Isotropic Liquid and Crystalline Phases of Benzil-Based Polycatenars. Chemistry 2020; 26:16066-16079. [PMID: 32652801 PMCID: PMC7756378 DOI: 10.1002/chem.202002869] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Indexed: 12/25/2022]
Abstract
Spontaneous development of chirality in systems composed of achiral molecules is important for new routes to asymmetric synthesis, chiral superstructures and materials, as well as for the understanding of the mechanisms of emergence of prebiotic chirality. Herein, it is shown that the 4,4'-diphenylbenzil unit is a universal transiently chiral bent building block for the design of multi-chained (polycatenar) rod-like molecules capable of forming a wide variety of helically twisted network structures in the liquid, the liquid crystalline (LC) and the crystalline state. Single polar substituents at the apex of tricatenar molecules support the formation of the achiral (racemic) cubic double network phase with Ia 3 ‾ d symmetry and relatively small twist along the networks. The combination of an alkyl chain with fluorine substitution leads to the homogeneously chiral triple network phase with I23 space group, and in addition, provides a mirror symmetry broken liquid. Replacing F by Cl or Br further increases the twist, leading to a short pitch double gyroid Ia 3 ‾ d phase, which is achiral again. The effects of the structural variations on the network structures, either leading to achiral phases or chiral conglomerates are analyzed.
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Affiliation(s)
- Tino Reppe
- Institute of ChemistryMartin Luther University Halle-WittenbergKurt-Mothes-Straße 206120HalleGermany
| | - Silvio Poppe
- Institute of ChemistryMartin Luther University Halle-WittenbergKurt-Mothes-Straße 206120HalleGermany
| | - Carsten Tschierske
- Institute of ChemistryMartin Luther University Halle-WittenbergKurt-Mothes-Straße 206120HalleGermany
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Reddy MG, Lobo NP, Roy A, Ramanathan KV, Narasimhaswamy T. Strikingly different molecular organization and molecular order of tetracatenar mesogens in columnar mesophases revealed by XRD and 13C NMR. Phys Chem Chem Phys 2020; 22:23986-23997. [PMID: 33073796 DOI: 10.1039/d0cp03933k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For a successful design of functional mesogens, it is paramount to understand factors that contribute to molecular organisation such as molecular shape, the non-covalent interactions of the constituent moieties as well as nanosegregation of incompatible molecular parts. In this study on four tetracatenar mesogens, we show that by a slight change in the length of the terminal chain, the molecular organization changes from lamellar to columnar phase and that the orientational order experiences profound change between the lamellar, the center rectangular columnar and the hexagonal columnar mesophases. We consider here, mesogens that exhibit lamellar and columnar mesophases with five phenyl rings in the central rod-like core which are subjected to XRD and high resolution solid state 13C NMR investigations in their mesophases. The XRD studies indicate that the lower homologs exhibit a lamellar mesophase while the higher homologs show either a centre rectangular columnar phase or a 2D hexagonal columnar mesophase. 13C NMR investigations reveal interesting and strikingly different molecular orientations in each of these phases. For example, values of order parameters of one of the phenyl rings in the core region of the mesogens vary from 0.75 and 0.77 for the lamellar mesogens to 0.45 and 0.17 for the centre rectangular columnar and the hexagonal columnar mesogens respectively. While these values indicate that the mesogenic molecules are oriented along the magnetic field as expected in the lamellar phases, the very low order parameter in the hexagonal columnar phase arises due to molecules distributed azimuthally in layers and undergoing motion about the columnar axis which itself is oriented orthogonal to the magnetic field. Such cutting edge information extracted from the combined use of XRD and 13C NMR studies on tetracatenar mesogens is expected to be of significant use for the study of π-conjugated polycatenar systems where functional properties depend on the molecular orientation and order.
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Affiliation(s)
- M Guruprasad Reddy
- Polymer Science and Technology, CSIR-Central Leather Research Institute, Adyar, Chennai 600020, India.
| | - Nitin P Lobo
- Centre for Analysis, Testing, Evaluation & Reporting Services (CATERS), CSIR-Central Leather Research Institute, Adyar, Chennai 600020, India
| | - Arun Roy
- Soft Condensed Matter, Raman Research Institute, Bangalore, 560080, India.
| | - K V Ramanathan
- NMR Research Centre, Indian Institute of Science, Bangalore, 560012, India.
| | - T Narasimhaswamy
- Polymer Science and Technology, CSIR-Central Leather Research Institute, Adyar, Chennai 600020, India.
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Herod JD, Bates MA, Whitwood AC, Bruce DW. Ionic N-phenylpyridinium tetracatenar mesogens: competing driving forces in mesophase formation and unprecedented difference in phase stabilisation within a homologous series. SOFT MATTER 2019; 15:4432-4436. [PMID: 31119242 DOI: 10.1039/c9sm00846b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ionic, tetracatenar liquid crystals containing an N-phenylpyridinum core are described; many of these compounds display a SmA phase, something extremely rare in tetracatenar materials. The competing forces driving mesophase formation lead to an unprecedented difference in phase stabilities for SmA and Colh phases.
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Affiliation(s)
- Jordan D Herod
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
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8
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Gainar A, Tzeng MC, Heinrich B, Donnio B, Bruce DW. Incompatibility-Driven Self-Organization in Polycatenar Liquid Crystals Bearing Both Hydrocarbon and Fluorocarbon Chains. J Phys Chem B 2017; 121:8817-8828. [PMID: 28829604 DOI: 10.1021/acs.jpcb.7b04490] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and liquid crystal properties are reported for tri- and tetra-catenar mesogens in which both hydrocarbon and semiperfluorocarbon chains have been incorporated. In the tricatenar mesogens, the lamellar spacing in the smectic C phase of the all-hydrocarbon mesogen almost doubles when the isolated hydrocarbon chain is replaced by a semiperfluorinated chain on account of the localized segregation in different sublayers between the two chain types. In the tetracatenar materials, the replacement of at least one hydrocarbon chain by semiperfluorocarbon chains is sufficient to promote columnar phase formation, but when the molecule has two hydrocarbon chains at one end and two semiperfluorocarbon chains at the other, the requirement for localized phase segregation leads to the formation of a rectangular phase with very large lattice parameters. The juxtaposition of terminal chains of different nature within the same molecular structure thus leads to a reduction in mesophase symmetry and the emergence of more complex supramolecular organization.
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Affiliation(s)
- Adrian Gainar
- Department of Chemistry, University of York , Heslington, York YO10 5DD, United Kingdom
| | - Mei-Chun Tzeng
- Department of Chemistry, University of York , Heslington, York YO10 5DD, United Kingdom
| | - Benoît Heinrich
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504) , 23 rue du Loess BP 43, 67034 Strasbourg Cedex 2, France
| | - Bertrand Donnio
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504) , 23 rue du Loess BP 43, 67034 Strasbourg Cedex 2, France
| | - Duncan W Bruce
- Department of Chemistry, University of York , Heslington, York YO10 5DD, United Kingdom
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Poppe M, Chen C, Ebert H, Poppe S, Prehm M, Kerzig C, Liu F, Tschierske C. Transition from nematic to gyroid-type cubic soft self-assembly by side-chain engineering of π-conjugated sticky rods. SOFT MATTER 2017; 13:4381-4392. [PMID: 28573294 DOI: 10.1039/c7sm00793k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A sequence of liquid crystalline phases, involving cybotactic nematics, a lamellar phase, bicontinuous cubics and triangular honeycombs, was observed for oligo(phenylene ethynylene) based X-shaped bolapolyphiles with two long lateral alkyl chains and sticky ends provided by glycerol groups. In the cubic phase with Ia3[combining macron]d lattice - which is tailored by alkyl chain engineering - the aromatic cores are organized on the gyroid minimal surface in 3D curved layers of almost parallel aligned π-conjugated rods. It is shown that this type of cubic phase is a general mode of soft self-assembly of X-shaped bolapolyphiles at the cross-over from the (long or short range) lamellar to the triangular honeycomb-like organization. Cubic phase formation is found only in a narrow range with respect to temperature and chain-length for the non-fluorinated compounds and in much wider ranges for related core-fluorinated molecules.
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Affiliation(s)
- Marco Poppe
- Institute of Chemistry, Martin-Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, D-06120 Halle/Saale, Germany.
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Poppe M, Chen C, Liu F, Poppe S, Tschierske C. Formation of a Cubic Liquid Crystalline Nanostructure with π-Conjugated Fluorinated Rods on the Gyroid Minimal Surface. Chemistry 2017; 23:7196-7200. [DOI: 10.1002/chem.201700905] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Marco Poppe
- Department of Chemistry; Martin Luther University Halle-Wittenberg; Kurt-Mothes-Strasse 2 06120 Halle Germany
| | - Changlong Chen
- State Key Laboratory for Mechanical Behavior of Materials; Xi'an Jiaotong University; Xi'an 710049 P.R. China
| | - Feng Liu
- State Key Laboratory for Mechanical Behavior of Materials; Xi'an Jiaotong University; Xi'an 710049 P.R. China
| | - Silvio Poppe
- Department of Chemistry; Martin Luther University Halle-Wittenberg; Kurt-Mothes-Strasse 2 06120 Halle Germany
| | - Carsten Tschierske
- Department of Chemistry; Martin Luther University Halle-Wittenberg; Kurt-Mothes-Strasse 2 06120 Halle Germany
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Ferreira M, Westphal E, Ballottin MV, Bechtold IH, Bortoluzzi AJ, Mezalira DZ, Gallardo H. Columnar bent-core liquid crystals with two oxadiazole units and two or four alkyl chains and their phase-dependent fluorescence. NEW J CHEM 2017. [DOI: 10.1039/c7nj00548b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Bent-core containing 1,3,4-oxadiazole units and strongly polar substituents are found to show a pronounced tendency to form hexagonal columnar mesophases.
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Affiliation(s)
- M. Ferreira
- Departamento de Química, Universidade Federal de Santa Catarina
- Florianópolis
- Brazil
| | - E. Westphal
- Departamento Acadêmico de Química e Biologia, Universidade Tecnológica Federal do Paraná
- Curitiba
- Brazil
| | - M. V. Ballottin
- Departamento de Física, Universidade Federal de Santa Catarina
- Florianópolis
- Brazil
| | - I. H. Bechtold
- Departamento de Física, Universidade Federal de Santa Catarina
- Florianópolis
- Brazil
| | - A. J. Bortoluzzi
- Departamento de Química, Universidade Federal de Santa Catarina
- Florianópolis
- Brazil
| | - D. Z. Mezalira
- Departamento de Química, Universidade Federal de Santa Catarina
- Florianópolis
- Brazil
| | - H. Gallardo
- Departamento de Química, Universidade Federal de Santa Catarina
- Florianópolis
- Brazil
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Kumar NSS, Shafikov MZ, Whitwood AC, Donnio B, Karadakov PB, Kozhevnikov VN, Bruce DW. Mesomorphism and Photophysics of Some Metallomesogens Based on Hexasubstituted 2,2':6', 2''-Terpyridines. Chemistry 2016; 22:8215-33. [PMID: 27138194 DOI: 10.1002/chem.201505072] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/23/2016] [Indexed: 11/06/2022]
Abstract
The luminescent and mesomorphic properties of a series of metal complexes based on hexacatenar 2,2':6',2''-terpyridines are investigated using experimental methods and density functional theory (DFT). Two types of ligand are examined, namely 5,5''-di(3,4,5-trialkoxyphenyl)terpyridine with or without a fused cyclopentene ring on each pyridine and their complexes were prepared with the following transition metals: Zn(II) , Co(III) , Rh(III) , Ir(III) , Eu(III) and Dy(III) . The exact geometry of some of these complexes was determined by single X-ray diffraction. All complexes with long alkyl chains were found to be liquid crystalline, which property was induced on complexation. The liquid-crystalline behaviour of the complexes was studied by polarising optical microscopy and small-angle X-ray diffraction. Some of the transition metal complexes (for example, those with Zn(II) and Ir(III) ) are luminescent in solution, the solid state and the mesophase; their photophysical properties were studied both experimentally and using DFT methods (M06-2X and B3LYP).
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Affiliation(s)
- N S Saleesh Kumar
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Marsel Z Shafikov
- Department of TOS, Institute of Chemical Engineering, Ural Federal University, 19 Mira str., Ekaterinburg, 620002, Russia
| | - Adrian C Whitwood
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Bertrand Donnio
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504), 23 rue du Loess BP 43, 67034, Strasbourg Cedex 2, France
| | - Peter B Karadakov
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Valery N Kozhevnikov
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.,Department of Applied Sciences, Northumbria University, Newcastle-Upon-Tyne, NE1 8ST, UK
| | - Duncan W Bruce
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.
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