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Knöller JA, Müller F, Matulaitis T, Dos Santos JM, Gupta AK, Zysman-Colman E, Laschat S. MR-TADF liquid crystals: towards self assembling host-guest mixtures showing narrowband emission from the mesophase. Chem Sci 2024:d4sc04429k. [PMID: 39397824 PMCID: PMC11467995 DOI: 10.1039/d4sc04429k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Accepted: 09/20/2024] [Indexed: 10/15/2024] Open
Abstract
Creating (room temperature) liquid crystalline TADF materials that retain the photophysical properties of the monomolecular TADF emitters remains a formidable challenge. The strong intramolecular interactions required for formation of a liquid crystal usually adversely affect the photophysical properties and balancing them is not yet possible. In this work, we present a novel host-guest approach enabling unperturbed, narrowband emission from an MR-TADF emissive core from strongly aggregated columnar hexagonal (Colh) liquid crystals. By modifying the DOBNA scaffold with mesogenic groups bearing alkoxy chains of different lengths, we created a library of Colh liquid crystals featuring phase ranges >100 K and room temperature mesomorphism. Expectedly, these exhibit broad excimer emission from their neat films, so we exploited their high singlet (S1 ∼2.9 eV) and triplet (T1 ∼2.5 eV) energies by doping them with the MR-TADF guest BCzBN. Upon excitation of the host, efficient Förster Resonance Energy Transfer (FRET) resulted in almost exclusive emission from BCzBN. The ability of the liquid crystallinity of the host to not be adversely affected by the presence of BCzBN is demonstrated as is the localization of the guest molecules within the aliphatic chain network of the host, resulting in extremely narrowband emission (FWHM = 14-15 nm). With this work we demonstrate a strategy for the self-assembly of materials with previously mutually incompatible properties in emissive liquid crystalline systems: strong aggregation in Colh mesophases, and narrowband emission from a MR-TADF core.
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Affiliation(s)
- Julius A Knöller
- Institute of Organic Chemistry, University of Stuttgart Pfaffenwaldring 55 D-70569 Stuttgart Germany
| | - Franziska Müller
- Institute of Organic Chemistry, University of Stuttgart Pfaffenwaldring 55 D-70569 Stuttgart Germany
| | - Tomas Matulaitis
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews St Andrews, Fife KY16 9ST UK +44 (0)1334 463808 +44 (0)1334 463826
| | - John M Dos Santos
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews St Andrews, Fife KY16 9ST UK +44 (0)1334 463808 +44 (0)1334 463826
| | - Abhishek Kumar Gupta
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews St Andrews, Fife KY16 9ST UK +44 (0)1334 463808 +44 (0)1334 463826
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews St Andrews, Fife KY16 9ST UK +44 (0)1334 463808 +44 (0)1334 463826
| | - Sabine Laschat
- Institute of Organic Chemistry, University of Stuttgart Pfaffenwaldring 55 D-70569 Stuttgart Germany
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Haketa Y, Yamasumi K, Maeda H. π-Electronic ion pairs: building blocks for supramolecular nanoarchitectonics viaiπ- iπ interactions. Chem Soc Rev 2023; 52:7170-7196. [PMID: 37795542 DOI: 10.1039/d3cs00581j] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
The pairing of charged π-electronic systems and their ordered arrangement have been achieved by iπ-iπ interactions that are derived from synergetically worked electrostatic and dispersion forces. Charged π-electronic systems that provide ion pairs as building blocks for assemblies have been prepared by diverse strategies for introducing charge in the core π-electronic systems. One method to prepare charged π-electronic systems is the use of covalent bonding that makes π-electronic ions and valence-mismatched metal complexes as well as protonated and deprotonated states. Noncovalent ion complexation is another method used to create π-electronic ions, particularly for anion binding, producing negatively charged π-electronic systems. Charged π-electronic systems afford various ion pairs, consisting of both cationic and anionic π-systems, depending on their combinations. Geometries and electronic states of the constituents in π-electronic ion pairs affect the photophysical properties and assembling modes. Recent progress in π-electronic ion pairs has revealed intriguing characteristics, including the transformation into radical pairs through electron transfer and the magnetic properties influenced by the countercations. Furthermore, the assembly states exhibit diversity as observed in crystals and soft materials including liquid-crystal mesophases. While the chemistry of ion pairs (salts) is well-established, the field of π-electronic ion pairs is relatively new; however, it holds great promise for future applications in novel materials and devices.
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Affiliation(s)
- Yohei Haketa
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.
| | - Kazuhisa Yamasumi
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.
| | - Hiromitsu Maeda
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.
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Yamasumi K, Sugiura S, Tanaka H, Maeda H. Charged π-Electronic Systems That Provide Assembled Structures. J SYN ORG CHEM JPN 2022. [DOI: 10.5059/yukigoseikyokaishi.80.232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | | | | | - Hiromitsu Maeda
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan Universit
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Macreadie LK, Gilchrist AM, McNaughton DA, Ryder WG, Fares M, Gale PA. Progress in anion receptor chemistry. Chem 2022. [DOI: 10.1016/j.chempr.2021.10.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Schmidt A, Heinrich B, Kirscher G, Chaumont A, Henry M, Kyritsakas N, Haketa Y, Maeda H, Mobian P. Dipyrrolyldiketonato Titanium(IV) Complexes from Monomeric to Multinuclear Architectures: Synthesis, Stability, and Liquid-Crystal Properties. Inorg Chem 2020; 59:12802-12816. [PMID: 32845621 DOI: 10.1021/acs.inorgchem.0c01846] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dipyrrolyldiketone ligands (dpkH) are used with Ti(OiPr)4 to afford monomeric titanium(IV) complexes displaying the general formula C2-[Ti(dpk)2(OiPr)2]. The dpkH ligands employed consist of two dipyrrolyldiketone compounds (2H and 3H) and three diphenyl-substituted analogues (4H-6H). The behavior of these octahedral [Ti(dpk)2(OiPr)2] species in solution was investigated by 1H NMR at variable temperatures. Dynamic phenomena were evidenced, and the activation parameters associated with these processes (ΔH⧧, ΔS⧧, and ΔG⧧) were retrieved. [Ti(dpk)2(OiPr)2] complexes are precursors for the formation of high-nuclearity aggregates whose structures depend on the substituents on the diketone backbone. The crystal structures of monomeric ([Ti(1)2(OiPr)2]; 1 is the 1,3-diphenyl-1,3-propanedionato ligand) and [Ti(2)2(OEt)2]), dimeric ([Ti2(1)4(μ2-O)2]), and tetrameric ([Ti4(4)8(μ2-O)4]) species have been established, and the origin of this structural diversity is discussed. The solid-state optical properties of several complexes were determined and interpreted with the help of DFT calculations. Finally, the dinuclear complex [Ti(6)2(μ2-O)2] was synthesized, where ligand 6 incorporates six long alkyl chains (C16H33). This complex shows rich mesomorphic properties, with an original room-temperature plastic crystal phase followed by a hexagonal columnar liquid-crystalline phase.
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Affiliation(s)
- Alexandra Schmidt
- Laboratoire de Chimie Moléculaire de l'Etat Solide, UMR 7140 UDS-CNRS, University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France
| | - Benoît Heinrich
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504 UDS-CNRS, University of Strasbourg, 23 rue du Loess, F-67034 Strasbourg, France
| | - Guillaume Kirscher
- Laboratoire de Chimie Moléculaire de l'Etat Solide, UMR 7140 UDS-CNRS, University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France
| | - Alain Chaumont
- Laboratoire de Chimie Moléculaire de l'Etat Solide, UMR 7140 UDS-CNRS, University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France.,Laboratoire de Modélisation et Simulations Moléculaires, UMR 7140 UDS-CNRS, University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France
| | - Marc Henry
- Laboratoire de Chimie Moléculaire de l'Etat Solide, UMR 7140 UDS-CNRS, University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France
| | - Nathalie Kyritsakas
- Laboratoire de Tectonique Moléculaire, UMR 7140 UDS-CNRS, University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France
| | - Yohei Haketa
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan
| | - Hiromitsu Maeda
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan
| | - Pierre Mobian
- Laboratoire de Chimie Moléculaire de l'Etat Solide, UMR 7140 UDS-CNRS, University of Strasbourg, 4 rue Blaise Pascal, F-67000 Strasbourg, France
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Sugiura S, Maeda H. Pyrrole-based anion-responsive π-electronic molecules as fluorescence sensors responsive to multiple stimuli. Org Biomol Chem 2020; 18:4433-4438. [PMID: 32469034 DOI: 10.1039/d0ob00952k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Introduction of electron-donating N,N-dimethylaminophenyl groups in dipyrrolyldiketone BF2 complexes as anion-responsive π-electronic molecules resulted in fascinating fluorescence properties. The fluorescence properties, which depended on the degree of photo-induced electron transfer, could be controlled by solvent polarity, anion binding and protonation.
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Affiliation(s)
- Shinya Sugiura
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.
| | - Hiromitsu Maeda
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.
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