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Zeng CY, Deng WJ, Zhao KQ, Redshaw C, Donnio B. Phenanthrothiophene-Triazine Star-Shaped Discotic Liquid Crystals: Synthesis, Self-Assembly, and Stimuli-Responsive Fluorescence Properties. Chemistry 2024; 30:e202400296. [PMID: 38427538 DOI: 10.1002/chem.202400296] [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: 01/23/2024] [Revised: 03/01/2024] [Accepted: 03/01/2024] [Indexed: 03/03/2024]
Abstract
Lipophilic biphenylthiophene- and phenanthrothiophene-triazine compounds, BPTTn and CPTTn, respectively, were prepared by a tandem procedure involving successive Suzuki-Miyaura coupling and Scholl cyclodehydrogenation reactions. These compounds display photoluminescence in solution and in thin film state, solvatochromism with increasing solvent's polarity, as well as acidochromism and metal ion recognition stimuli-responsive fluorescence. Protonation of BPTT10 and CPTT10 by trifluoroacetic acid results in fluorescence quenching, which is reversibly restored once treated with triethylamine (ON-OFF switch). DFT computational studies show that intramolecular charge transfer (ICT) phenomena occurs for both molecules, and reveal that protonation enhances the electron-withdrawing ability of the triazine core and reduces the band gap. This acidochromic behavior was applied to a prototype fluorescent anti-counterfeiting device. They also specifically recognize Fe3+ through coordination, and the recognition mechanism is closely related to the photoinduced electron transfer between Fe3+ and BPTT10/CPTT10. CPTTn self-assemble into columnar rectangular (Colrec) mesophase, which can be modulated by oleic acid via the formation of a hydrogen-bonded supramolecular liquid crystal hexagonal Colhex mesophase. Finally, CPTTn also form organic gels in alkanes at low critical gel concentration (3.0 mg/mL). Therefore, these star-shaped triazine molecules possess many interesting features and thus hold great promises for information processing, liquid crystal semiconductors and organogelators.
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Affiliation(s)
- Chong-Yang Zeng
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Wen-Jing Deng
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Ke-Qing Zhao
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Carl Redshaw
- Department of Chemistry, University of Hull, School of Natural Sciences, Hull, HU6 7RX, UK
| | - Bertrand Donnio
- Institut de Chimie et Physique des Matériaux de Strasbourg, UMR 7504, CNRS-University of Strasbourg, 67034, Strasbourg, France
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Zhang KL, Yu WH, Zhao KQ, Hu P, Wang BQ, Donnio B. Mesomorphism Modulation of Perfluorinated Janus Triphenylenes by Inhomogeneous Chain Substitution Patterns. Chem Asian J 2024:e202301080. [PMID: 38214422 DOI: 10.1002/asia.202301080] [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: 11/30/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 01/13/2024]
Abstract
Two isomeric series of compounds with "inverted" chains' substitution patterns, 7,10-dialkoxy-1,2,3,4-tetrafluoro-6,11-dimethoxytriphenylene and 6,11-dialkoxy-1,2,3,4-tetrafluoro-7,10-dimethoxytriphenylene, labelled respectively p-TPFn and m-TPFn, and two non-fluorinated homologous isomers, 3,6-dibutoxy-2,7-dimethoxytriphenylene and 2,7-dibutoxy-3,6-dimethoxytriphenylene, p-TP4 and m-TP4, respectively, were synthesized in three steps and obtained in good yields by the efficient transition-metal-free, fluoroarene nucleophilic substitution via the reaction of appropriate 2,2'-dilithium biphenylenes with either perfluorobenzene, C6 F6 , to yield p-TPFn and m-TPFn, or o-difluorobenzene, C6 H4 F2 , for p-TP4 and m-TP4, respectively. The single-crystal structures of p-TPF4, m-TPF4 and p-TP4, unequivocally confirmed that the cyclization reactions occurred at the expected positions, and that the fluorinated molecules stack up into columns with short separation, a propitious situation for the emergence of columnar mesophases. The mesomorphous properties were found to be greatly affected by both chains' length and positional isomerism: a Colhex phase is found for p-TPF4 and m-TPF4, but mesomorphism vanishes in p-TPF6, and changes for the isomeric homologs m-TPFn, with the induction for n≥6 of a lamello-columnar phase, LamColrec . As expected, both non-fluorinated compounds are deprived of mesomorphism. These compounds emit blue-violet colour in solution, independently of the chains' substitution pattern, and the absolute fluorescence quantum yields can reach up to 46 %. In thin films, fluorescence is slightly redshifted.
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Affiliation(s)
- Kai-Li Zhang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Wen-Hao Yu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Ke-Qing Zhao
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Ping Hu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Bi-Qin Wang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Bertrand Donnio
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504), F-67034, cedex 2 Strasbourg, France
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Zhou MM, He J, Pan HM, Zeng Q, Lin H, Zhao KQ, Hu P, Wang BQ, Donnio B. Induction and Stabilization of Columnar Mesophases in Fluorinated Polycyclic Aromatic Hydrocarbons by Arene-Perfluoroarene Interactions. Chemistry 2023; 29:e202301829. [PMID: 37452614 DOI: 10.1002/chem.202301829] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/06/2023] [Accepted: 07/08/2023] [Indexed: 07/18/2023]
Abstract
The straightforward synthesis of several Fluorinated Polycyclic Aromatic Hydrocarbons by the efficient, transition-metal-free, arene fluorine nucleophilic substitution reaction is described, and the full investigation of their liquid crystalline and optical properties reported. The key precursors for this study, i. e. 2,2'-dilithio-4,4',5,5'-tetraalkoxy-1,1'-biphenyl derivatives, were obtained in two steps from the highly selective Scholl oxidative homo-coupling of 3,4-dialkoxy-1-bromobenzene, followed by quantitative double-lithiation. In situ room temperature nucleophilic annulation with either perfluorobenzene or perfluoronaphthalene leads to 1,2,3,4-tetrafluoro-6,7,10,11-tetraalkxoytriphenylenes and 9,10,11,12,13,14-hexafluoro-2,3,6,7-tetraalkoxybenzo[f]tetraphenes, respectively, in good yields. Exploiting the same strategy, subsequent double annulations resulted in the formation of 9,18-difluoro-2,3,6,7,11,12,15,16-octa(alkoxy)tribenzo[f,k,m]tetraphenes and 9,10,19,20-tetrafluoro-2,3,6,7,12,13,16,17-octakis(hexyloxy)tetrabenzo[a,c,j,l]tetracenes, respectively. Despite the presence of only four alkoxy chains, the polar "Janus" mesogens display a columnar hexagonal mesophase over broad temperature ranges, with higher mesophase stability than the archetypical 2,3,6,7,10,11-hexa(alkoxy)triphenylenes and their hydrogenated counterparts. The improvement or induction of mesomorphism is attributed to efficient antiparallel face-to-face π-stacking driven by the establishment of non-covalent perfluoroarene-arene intermolecular interactions. The larger lipophilic discotic π-extended compounds also exhibit columnar mesomorphism, over similar temperature ranges and stability than their hydrogenated homologs. Finally, these fluorinated molecules form stringy gels in various solvents, and show interesting solvatochromic emission properties in solution as well as strong emission in thin films and gels.
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Affiliation(s)
- Ming-Mei Zhou
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Jiao He
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Hui-Min Pan
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Qing Zeng
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Hang Lin
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Ke-Qing Zhao
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Ping Hu
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Bi-Qin Wang
- College of Chemistry and Materials Science, Sichuan Normal University, 610066, Chengdu, China
| | - Bertrand Donnio
- Institut de Physique et Chimie de Strasbourg, CNRS-Université de Strasbourg (UMR7504), 67000, Strasbourg, France
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Zeng Q, Liu S, Lin H, Zhao KX, Bai XY, Zhao KQ, Hu P, Wang BQ, Donnio B. Pyrene-Fused Poly-Aromatic Regioisomers: Synthesis, Columnar Mesomorphism, and Optical Properties. Molecules 2023; 28:molecules28041721. [PMID: 36838709 PMCID: PMC9959431 DOI: 10.3390/molecules28041721] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/16/2023] Open
Abstract
π-Extended pyrene compounds possess remarkable luminescent and semiconducting properties and are being intensively investigated as electroluminescent materials for potential uses in organic light-emitting diodes, transistors, and solar cells. Here, the synthesis of two sets of pyrene-containing π-conjugated polyaromatic regioisomers, namely 2,3,10,11,14,15,20,21-octaalkyloxypentabenzo[a,c,m,o,rst]pentaphene (BBPn) and 2,3,6,7,13,14,17,18-octaalkyloxydibenzo[j,tuv]phenanthro [9,10-b]picene (DBPn), is reported. They were obtained using the Suzuki-Miyaura cross-coupling in tandem with Scholl oxidative cyclodehydrogenation reactions from the easily accessible precursors 1,8- and 1,6-dibromopyrene, respectively. Both sets of compounds, equipped with eight peripheral aliphatic chains, self-assemble into a single hexagonal columnar mesophase, with one short-chain BBPn homolog also exhibiting another columnar mesophase at a lower temperature, with a rectangular symmetry; BBPn isomers also possess wider mesophase ranges and higher mesophases' stability than their DBPn homologs. These polycyclic aromatic hydrocarbons all show a strong tendency of face-on orientation on the substrate and could be controlled to edge-on alignment through mechanical shearing of interest for their implementation in photoelectronic devices. In addition, both series BBPn and DBPn display green-yellow luminescence, with high fluorescence quantum yields, around 30%. In particular, BBPn exhibit a blue shift phenomenon in both absorption and emission with respect to their DBPn isomers. DFT results were in good agreement with the optical properties and with the stability ranges of the mesophases by confirming the higher divergence from the flatness of DBPn compared with BBPn. Based on these interesting properties, these isomers could be potentially applied not only in the field of fluorescent dyes but also in the field of organic photoelectric semiconductor materials as electron transport materials.
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Affiliation(s)
- Qing Zeng
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
| | - Shuai Liu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
| | - Hang Lin
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
| | - Ke-Xiao Zhao
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
| | - Xiao-Yan Bai
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
| | - Ke-Qing Zhao
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
- Correspondence: (K.-Q.Z.); (B.D.)
| | - Ping Hu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
| | - Bi-Qin Wang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
| | - Bertrand Donnio
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504), 67034 Strasbourg, France
- Correspondence: (K.-Q.Z.); (B.D.)
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Wang B, Ding W, Zhang L, Meng X. Construction of Polyaromatic Hydrocarbons Containing Sulfur and Nitrogen via Controllable Domino Reactions and DFT Studies. Org Lett 2023; 25:140-145. [PMID: 36580410 DOI: 10.1021/acs.orglett.2c03958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Polyaromatic hydrocarbons (PHAs) containing heteroatoms have attracted considerable attention due to their potential utility in electronic devices. This work reported a novel domino reaction between an aryne precursor and azadiene bearing a benzothiophene moiety to produce a series of PHAs containing sulfur and nitrogen atoms. Further transformation of the product enabled concise synthesis of a new AIEgen, whose photophysical properties were characterized. Density functional calculations on the reaction mechanism revealed that the in situ generated aryne could trigger either a [4 + 2] or [3 + 2] process with azadiene, in which the regioselectivity was mainly a result of the heteroatom effect and may be understood by means of Houk's distortion-interaction model.
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Affiliation(s)
- Baoxin Wang
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry & Chemical Engineering, Tianjin University of Technology, Tianjin 300384, P. R. China
| | - Wenhuan Ding
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry & Chemical Engineering, Tianjin University of Technology, Tianjin 300384, P. R. China
| | - Lei Zhang
- Tianjin Engineering Technology Center of Chemical Wastewater Source Reduction and Recycling, School of Science, Tianjin Chengjian University, Tianjin 300384, P. R. China
| | - Xiangtai Meng
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry & Chemical Engineering, Tianjin University of Technology, Tianjin 300384, P. R. China
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