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Wang Y, Yang SG, Li YX, Cao Y, Liu F, Zeng XB, Cseh L, Ungar G. Supertwisted Chiral Gyroid Mesophase in Chiral Rod-Like Compounds. Angew Chem Int Ed Engl 2024; 63:e202403156. [PMID: 38566540 DOI: 10.1002/anie.202403156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/04/2024]
Abstract
Among the intriguing bicontinuous self-assembled structures, the gyroid cubic is the most ubiquitous. It is found in block and star polymers, surfactants with or without solvent, in thermotropic liquid crystals with end- or side-chains, and in biosystems providing structural color and modelling cell mitosis. It contains two interpenetrating networks of opposite chirality and is thus achiral if, as usual, the content of the two nets is the same. However, we now find that this is not the case for strongly chiral compounds. While achiral molecules follow the opposite twists of nets 1 and 2, molecules with a chiral center in their rod-like core fail to follow the 70° twist between junctions in net 2 and instead wind against it by -110° to still match the junction orientation. The metastable chiral gyroid is a high-entropy high-heat-capacity mesophase. The homochirality of its nets makes the CD signal of the thienofluorenone compounds close to that in the stable I23 phase with 3 isochiral nets.
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Affiliation(s)
- Yan Wang
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Shu-Gui Yang
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Ya-Xin Li
- School of Chemistry and Chemical Engineering, Henan University of Technology, 450001, Zhengzhou, China
| | - Yu Cao
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Feng Liu
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Xiang-Bing Zeng
- Department of Materials Science and Engineering, University of Sheffield, S1 3JD, Sheffield, UK
| | - Liliana Cseh
- Romanian Academy, Coriolan Dragulescu Institute of Chemistry, 300223, Timisoara, Romania
| | - Goran Ungar
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China
- Department of Materials Science and Engineering, University of Sheffield, S1 3JD, Sheffield, UK
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2
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Elstone N, Shimizu K, Shaw EV, Lane PD, D’Andrea L, Demé B, Mahmoudi N, Rogers SE, Youngs S, Costen ML, McKendrick KG, Canongia Lopes JN, Bruce DW, Slattery JM. Understanding the Liquid Structure in Mixtures of Ionic Liquids with Semiperfluoroalkyl or Alkyl Chains. J Phys Chem B 2023; 127:7394-7407. [PMID: 37555779 PMCID: PMC10461228 DOI: 10.1021/acs.jpcb.3c02647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/15/2023] [Indexed: 08/10/2023]
Abstract
By mixing ionic liquids (ILs), it is possible to fine-tune their bulk and interfacial structure. This alters their physical properties and solvation behavior and is a simple way to prepare a collection of ILs whose properties can be tuned to optimize a specific application. In this study, mixtures of perfluorinated and alkylated ILs have been prepared, and links between composition, properties, and nanostructure have been investigated. These different classes of ILs vary substantially in the flexibility and polarizability of their chains. Thus, a range of useful structural and physical property variations are accessible through mixing that will expand the library of IL mixtures available in an area that to this point has received relatively little attention. In the experiments presented herein, the physical properties and bulk structure of mixtures of 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide [C8MIM][Tf2N] and 1-(1H,1H,2H,2H-perfluorooctyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C8MIM-F13][Tf2N] have been prepared. The bulk liquid structure was investigated using a combination of small-angle X-ray and neutron scattering (SAXS and SANS, respectively) experiments in combination with atomistic molecular dynamics simulations and the measurement of density and viscosity. We observed that the addition of [C8MIM-F13][Tf2N] to [C8MIM][Tf2N] causes changes in the nanostructure of the IL mixtures that are dependent on composition so that variation in the characteristic short-range correlations is observed as a function of composition. Thus, while the length scales associated with the apolar regions (polar non-polar peak─PNPP) increase with the proportion of [C8MIM-F13][Tf2N] in the mixtures, perhaps surprisingly given the greater volume of the fluorocarbon chains, the length scale of the charge-ordering peak decreases. Interestingly, consideration of the contact peak shows that its origins are both in the direct anion···cation contact length scale and the nature (and hence volume) of the chains appended to the imidazolium cation.
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Affiliation(s)
- Naomi
S. Elstone
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Karina Shimizu
- Centro
de Química Estrutural, Institute of Molecular Sciences, Instituto
Superior Técnico, Universidade de
Lisboa, Av. Rovisco Pais, Lisboa 1049 001, Portugal
| | - Emily V. Shaw
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Paul D. Lane
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot−Watt University, Edinburgh EH14 4AS, U.K.
| | - Lucía D’Andrea
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Bruno Demé
- Institut
Laue−Langevin, Grenoble 38000, France
| | - Najet Mahmoudi
- ISIS
Neutron Source Facility, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Sarah E. Rogers
- ISIS
Neutron Source Facility, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Sarah Youngs
- ISIS
Neutron Source Facility, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
| | - Matthew L. Costen
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot−Watt University, Edinburgh EH14 4AS, U.K.
| | - Kenneth G. McKendrick
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot−Watt University, Edinburgh EH14 4AS, U.K.
| | - Jose N. Canongia Lopes
- Centro
de Química Estrutural, Institute of Molecular Sciences, Instituto
Superior Técnico, Universidade de
Lisboa, Av. Rovisco Pais, Lisboa 1049 001, Portugal
| | - Duncan W. Bruce
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - John M. Slattery
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
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3
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Wang Y, Li YX, Cseh L, Chen YX, Yang SG, Zeng X, Liu F, Hu W, Ungar G. Enantiomers Self-Sort into Separate Counter-Twisted Ribbons of the Fddd Liquid Crystal─Antiferrochirality and Parachirality. J Am Chem Soc 2023; 145:17443-17460. [PMID: 37523689 PMCID: PMC10416214 DOI: 10.1021/jacs.3c06164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Indexed: 08/02/2023]
Abstract
The recently discovered orthorhombic liquid crystal (LC) phase of symmetry Fddd is proving to be widespread. In this work, a chiral hydroxybutyrate linkage is inserted into the molecular core of hexacatenar rodlike compounds, containing a thienylfluorenone fluorophore. In addition to more usual tools, the methods used include grazing-incidence X-ray scattering, modulated differential scanning calorimetry (DSC), flash DSC with rates up to 6000 K/s, and chiro-optical spectroscopies using Mueller matrix method, plus conformational mapping. Although pure R and S enantiomers form only a strongly chiral hexagonal columnar LC phase (Colh*), the racemic mixture forms a highly ordered Fddd phase with 4 right- and 4 left-handed twisted ribbon-like columns traversing its large unit cell. In that structure, the two enantiomers locally deracemize and self-sort into the columns of their preferred chirality. The twisted ribbons in Fddd, with a 7.54 nm pitch, consist of stacked rafts, each containing ∼2 side-by-side molecules, the successive rafts rotated by 17°. In contrast, an analogous achiral compound forms only the columnar phase. The multiple methods used gave a comprehensive picture and helped in-depth understanding not only of the Fddd phase but also of the "parachiral" Colh* in pure enantiomers with irregular helicity, whose chirality is compared to the magnetization of a paramagnet in a field. Unusual short-range ordering effects are also described. An explanation of these phenomena is proposed based on conformational analysis. Surprisingly, the isotropic-columnar transition is extremely fast, completing within ∼20 ms. A clear effect of phase on UV-vis absorption and emission is observed.
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Affiliation(s)
- Yan Wang
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Ya-Xin Li
- School
of Chemistry and Chemical Engineering, Henan
University of Technology, Zhengzhou 450001, China
| | - Liliana Cseh
- Romanian
Academy, Coriolan Dragulescu Institute of Chemistry, Timisoara 300223, Romania
| | - Yong-Xuan Chen
- State
Key Laboratory of Coordinate Chemistry, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210093, China
| | - Shu-Gui Yang
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Xiangbing Zeng
- Department
of Materials Science and Engineering, University
of Sheffield, Sheffield S1 3JD, U.K.
| | - Feng Liu
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
| | - Wenbing Hu
- State
Key Laboratory of Coordinate Chemistry, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210093, China
| | - Goran Ungar
- Shaanxi
International Research Centre for Soft Matter, State Key Laboratory
for Mechanical Behaviour of Materials, Xi’an
Jiaotong University, Xi’an 710049, China
- Department
of Materials Science and Engineering, University
of Sheffield, Sheffield S1 3JD, U.K.
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4
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Parker R, Stracey RF, McEllin AJ, Chen X, Wang Y, Williams JAG, Lynam JM, Bruce DW. Synthesis, Mesomorphism, Photophysics, and Device Properties of Liquid-Crystalline Pincer Complexes of Gold(III) Containing Semiperfluorinated Chains. ACS OMEGA 2022; 7:24903-24917. [PMID: 35874197 PMCID: PMC9301954 DOI: 10.1021/acsomega.2c03669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Gold(III) complexes of C∧N∧C-coordinating 2,6-diphenylpyridine pincer ligands with arylacetylide co-ligands are known triplet emitters at room temperature. We have reported previously that by functionalizing both the pincer ligand and the phenylacetylene with alkoxy chains, liquid crystallinity may be induced, with the complexes showing columnar mesophases. We now report new derivatives in which the phenylacetylene incorporates one, two, or three 1H,1H,2H,2H-perfluoroalkyl chains. In terms of intermolecular interactions, solution 1H NMR experiments suggest that the semiperfluoroalkyl chains promote a parallel, head-to-head arrangement of neighboring molecules relative to one another, rather than the anti-parallel, head-to-tail orientation found for the all-hydrocarbon materials. In terms of the liquid crystal properties, the complexes show columnar phases, with the addition of the more rigid fluorocarbon chains leading to a stabilization of both the crystal and liquid crystal mesophases. Mesophase temperature ranges were also wider. Interestingly, the amphiphilic nature of these complexes is evident through the observation of a frustrated columnar nematic phase between a Colr and a Colh phase, an observation recently reported in detail for one compound (Liq. Cryst., 2022, doi: 10.1080/02678292.2021.1991017). While calculation shows that, despite the "electronic insulation" provided by the dimethylene spacer group in the semiperfluoroalkyl chains, a small hypsochromic shift in one component of the absorption band is anticipated, experimentally this effect is not observed in the overall absorption envelope. Complexes with substituents in the 3,3',4,4'-positions of the phenyl rings of the pincer ligand once more show higher-luminescence quantum yields than the analogues with substituents in the 4,4'-positions only, associated with the lower-energy-emissive state in the former. However, in contrast to the observations with all-hydrocarbon analogues, the luminescence quantum yield of the complexes with 3,3',4,4'-substitution on the pincer increases as the number of semiperfluoroalkyl chains on the phenylacetylide increases, from 20% (one chain) to 34% (three chains). External quantum efficiencies in fabricated OLED devices are, however, low, attributed to the poor dispersion in the host materials on account of the fluorinated chains.
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Affiliation(s)
- Rachel
R. Parker
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Rachel F. Stracey
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Alice J. McEllin
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Xinrui Chen
- School
of Materials Science & Engineering, Changzhou University, Changzhou 213164, PR China
| | - Yafei Wang
- School
of Materials Science & Engineering, Changzhou University, Changzhou 213164, PR China
| | - J. A. Gareth Williams
- Department
of Chemistry, University Science Laboratories, Durham University, South Road, Durham DH1
3LE, U.K.
| | - Jason M. Lynam
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Duncan W. Bruce
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
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5
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Li YX, Gao HF, Zhang RB, Gabana K, Chang Q, Gehring GA, Cheng XH, Zeng XB, Ungar G. A case of antiferrochirality in a liquid crystal phase of counter-rotating staircases. Nat Commun 2022; 13:384. [PMID: 35046396 PMCID: PMC8770800 DOI: 10.1038/s41467-022-28024-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 12/16/2021] [Indexed: 11/25/2022] Open
Abstract
Helical structures continue to inspire, prompted by examples such as DNA double-helix and alpha-helix in proteins. Most synthetic polymers also crystallize as helices, which relieves steric clashes by twisting, while keeping the molecules straight for their ordered packing. In columnar liquid crystals, which often display useful optoelectronic properties, overall helical chirality can be induced by inclusion of chiral chemical groups or dopants; these bias molecular twist to either left or right, analogous to a magnetic field aligning the spins in a paramagnet. In this work, however, we show that liquid-crystalline columns with long-range helical order can form by spontaneous self-assembly of straight- or bent-rod molecules without inclusion of any chiral moiety. A complex lattice with Fddd symmetry and 8 columns per unit cell (4 right-, 4 left-handed) characterizes this "antiferrochiral" structure. In selected compounds it allows close packing of their fluorescent groups reducing their bandgap and giving them promising light-emitting properties.
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Affiliation(s)
- Ya-Xin Li
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Centre for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, P. R. China
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD, UK
- School of Chemistry and Chemical Engineering, Henan University of Technology, 450001, Zhengzhou, P. R. China
| | - Hong-Fei Gao
- Key Laboratory of Medicinal Chemistry from Natural Resources, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Rui-Bin Zhang
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - Kutlwano Gabana
- Department of Physics and Astronomy, University of Sheffield, Sheffield, E1 2C, UK
| | - Qing Chang
- Key Laboratory of Medicinal Chemistry from Natural Resources, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Gillian A Gehring
- Department of Physics and Astronomy, University of Sheffield, Sheffield, E1 2C, UK
| | - Xiao-Hong Cheng
- Key Laboratory of Medicinal Chemistry from Natural Resources, Ministry of Education, Yunnan University, Kunming, P. R. China.
- School of Chemistry and Chemical Engineering, Yangtze Normal University, Fuling, P. R. China.
| | - Xiang-Bing Zeng
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD, UK.
| | - Goran Ungar
- State Key Laboratory for Mechanical Behaviour of Materials, Shaanxi International Research Centre for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, P. R. China.
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD, UK.
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6
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Riccobono A, Whitwood AC, Parker RR, Hart S, Pace A, Slattery JM, Pibiri I, Bruce DW. Crystal and molecular structure of series of triphilic ionic liquid-crystalline materials based on the 1,2,4-triazolium cation. CrystEngComm 2022. [DOI: 10.1039/d2ce01354a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The solid-state structure of sixteen triphilic triazolium salts with different anions is considered in terms of the potentially competing factors driving organisation.
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Affiliation(s)
- Alessio Riccobono
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Viale delle Scienze, Ed. 1790128 Palermo, Italy
| | - Adrian C. Whitwood
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Rachel R. Parker
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Sam Hart
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Andrea Pace
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Viale delle Scienze, Ed. 1790128 Palermo, Italy
| | - John M. Slattery
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Ivana Pibiri
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Viale delle Scienze, Ed. 1790128 Palermo, Italy
| | - Duncan W. Bruce
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
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7
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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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8
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Ndaya D, Bosire R, Vaidya S, Kasi RM. Molecular engineering of stimuli-responsive, functional, side-chain liquid crystalline copolymers: synthesis, properties and applications. Polym Chem 2020. [DOI: 10.1039/d0py00749h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review describes recent progress made in designing stimuli-responsive, functional, side-chain, end-on mesogen attached liquid crystalline polymers (LCPs).
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Affiliation(s)
- Dennis Ndaya
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
| | - Reuben Bosire
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
| | | | - Rajeswari M. Kasi
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
- Polymer Program
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9
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Cheng H, Gao H, Xiao Y, Zhang B, Xing W, Cheng X. Self-assembly, conductivity and chemosensor behavior of biphenylsulfone based Janus polycatenar. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.05.053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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