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Narita H, Min H, Kubo N, Hattori I, Yasuda T, Yamaguchi S. Bis-Ortho-Donor-Modification of Boracyclic π-Electron Systems beyond Steric Protection to Produce Thermally Activated Delayed Fluorescence Materials. Angew Chem Int Ed Engl 2024; 63:e202405412. [PMID: 38714489 DOI: 10.1002/anie.202405412] [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: 03/19/2024] [Revised: 05/02/2024] [Accepted: 05/02/2024] [Indexed: 05/10/2024]
Abstract
Polycyclic π-conjugated compounds that contain tricoordinate boron atoms at their periphery represent an attractive class of materials with electron-accepting character. Their molecular design generally requires the introduction of a bulky aryl group onto the boron atom, where it provides predominantly kinetic stabilization. The addition of extra functionality to the aryl group on the boron atom can be expected to further expand the potential utility of this class of materials. Herein, we report the synthesis of a series of boracyclic π-conjugated molecules with firm ortho B⋅⋅⋅N nonbonding interactions by introducing N-containing electron-donors at the ortho-positions of the aryl group on the boron atom. X-ray crystallographic analysis revealed that the combination of a planar boracyclic π-skeleton with only sp2 carbons and a strong electron-donating phenothiazine moiety results in a particularly short B⋅⋅⋅N distance. Theoretical study provided insights into the inherent nature of the B⋅⋅⋅N interaction. Owing to their donor-acceptor (D-A) structures, these molecules exhibit substantially red-shifted fluorescence in solution, albeit that the fluorescence quantum yields (ΦF) are low. In contrast, when incorporated into films, these compounds exhibit thermally activated delayed fluorescence (TADF) with improved ΦF values. Organic light-emitting diodes (OLEDs) fabricated using the ortho-donor-substituted derivatives exhibit orange-red electroluminescence.
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Affiliation(s)
- Hiroki Narita
- Department of Chemistry, Graduate School of Science, Research Center for Materials Science (RCMS), Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Hyukgi Min
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Nanami Kubo
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Izumi Hattori
- Department of Chemistry, Graduate School of Science, Research Center for Materials Science (RCMS), Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Takuma Yasuda
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shigehiro Yamaguchi
- Department of Chemistry, Graduate School of Science, Research Center for Materials Science (RCMS), Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8601, Japan
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Yang B, Zhang YM, Wang C, Gu C, Li C, Yin H, Yan Y, Yang G, Zhang SXA. An electrochemically responsive B-O dynamic bond to switch photoluminescence of boron-nitrogen-doped polyaromatics. Nat Commun 2024; 15:5166. [PMID: 38886345 PMCID: PMC11183244 DOI: 10.1038/s41467-024-48918-6] [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: 11/17/2023] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
Boron-doped polycyclic aromatic hydrocarbons exhibit excellent optical properties, and regulating their photophysical processes is a powerful strategy to understand the luminescence mechanism and develop new materials and applications. Herein, an electrochemically responsive B-O dynamic coordination bond is proposed, and used to regulate the photophysical processes of boron-nitrogen-doped polyaromatic hydrocarbons. The formation of the B-O coordination bond under a suitable voltage is confirmed by experiments and theoretical calculations, and B-O coordination bond can be broken back to the initial state under opposite voltage. The whole process is accompanied by reversible changes in photophysical properties. Further, electrofluorochromic devices are successfully prepared based on the above electrochemically responsive coordination bond. The success and harvest of this exploration are beneficial to understand the luminescence mechanism of boron-nitrogen-doped polyaromatic hydrocarbons, and provide ideas for design of dynamic covalent bonds and broaden material types and applications.
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Affiliation(s)
- Baige Yang
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China
| | - Yu-Mo Zhang
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China.
| | - Chunyu Wang
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China
| | - Chang Gu
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China
| | - Chenglong Li
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China.
| | - Hang Yin
- Institute of Atomic and Molecular Physics, Jilin University, Changchun, P. R. China.
| | - Yan Yan
- College of Instrumentation & Electrical Engineering, Jilin University, Changchun, P. R. China
| | - Guojian Yang
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China
| | - Sean Xiao-An Zhang
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China.
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Ruan L, Luo W, Zhang H, Liu P, Shi Y, An P. Cycl[2,2,4]azine-embedded non-alternant nanographenes containing fused antiaromatic azepine ring. Chem Sci 2024; 15:1511-1519. [PMID: 38274082 PMCID: PMC10806646 DOI: 10.1039/d3sc05515a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/14/2023] [Indexed: 01/27/2024] Open
Abstract
The development of non-alternant nanographenes has attracted considerable attention due to their unique photophysical properties. Herein, we reported a novel aza-doped, non-alternant nanographene (NG) 1 by embedding the cycl[2,2,4]azine unit into the benzenoid NG framework. Single-crystal X-ray diffractometry suggests saddle or twisted nonplanar geometry of the entire backbone of 1 and coplanar conformation of the cycl[2,2,4]azine unit. DFT calculation together with solid structure indicates that NG 1 possesses significant local antiaromaticity in the azepine ring. By oxidative process or trifluoroacetic acid treatment, this nanographene can transform into a mono-radical cation, which was confirmed by UV/Vis absorption, 1H NMR, and electron paramagnetic resonance (EPR) spectroscopy. The antiaromaticity/aromaticity switching of the azepine ring on 1˙+ from 1 enables the high stability of this radical cation, which remained intact for over 1 day. Due to the electron-donating nature of the nitrogen and the unique electronic structure, NG 1 exhibits strong electron-donating properties, as proved by the intermolecular charge transfer towards C60 with a high association constant. Furthermore, selective modification of NG 1 was accomplished by Vilsmeier reaction, and the derivatives 7 and 8 with substituted benzophenone were obtained. The photophysical and electronic properties can be tuned by the introduction of different electronic groups in benzophenone.
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Affiliation(s)
- Lan Ruan
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Wanhua Luo
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Haifan Zhang
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Peng Liu
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Yong Shi
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Peng An
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan University Kunming 650091 P. R. China
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Wu SH, Zhang Z, Zheng RH, Yang R, Wang L, Shao JY, Gong ZL, Zhong YW. Dual-Emissive Monoruthenium Complexes of N(CH 3)-Bridged Ligand: Synthesis, Characterization, and Substituent Effect. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6792. [PMID: 37895773 PMCID: PMC10607950 DOI: 10.3390/ma16206792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/13/2023] [Accepted: 10/19/2023] [Indexed: 10/29/2023]
Abstract
Three monoruthenium complexes 1(PF6)2-3(PF6)2 bearing an N(CH3)-bridged ligand have been synthesized and characterized. These complexes have a general formula of [Ru(bpy)2(L)](PF6)2, where L is a 2,5-di(N-methyl-N'-(pyrid-2-yl)amino)pyrazine (dapz) derivative with various substituents, and bpy is 2,2'-bipyridine. The photophysical and electrochemical properties of these compounds have been examined. The solid-state structure of complex 3(PF6)2 is studied by single-crystal X-ray analysis. These complexes show two well-separated emission bands centered at 451 and 646 nm (Δλmax = 195 nm) for 1(PF6)2, 465 and 627 nm (Δλmax = 162 nm) for 2(PF6)2, and 455 and 608 nm (Δλmax = 153 nm) for 3(PF6)2 in dilute acetonitrile solution, respectively. The emission maxima of the higher-energy emission bands of these complexes are similar, while the lower-energy emission bands are dependent on the electronic nature of substituents. These complexes display two consecutive redox couples owing to the stepwise oxidation of the N(CH3)-bridged ligand and ruthenium component. Moreover, these experimental observations are analyzed by computational investigation.
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Affiliation(s)
- Si-Hai Wu
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (Z.Z.); (R.-H.Z.); (R.Y.)
| | - Zhe Zhang
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (Z.Z.); (R.-H.Z.); (R.Y.)
| | - Ren-Hui Zheng
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (Z.Z.); (R.-H.Z.); (R.Y.)
| | - Rong Yang
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (Z.Z.); (R.-H.Z.); (R.Y.)
| | - Lianhui Wang
- School of Medicine, Huaqiao University, Quanzhou 362021, China; (Z.Z.); (R.-H.Z.); (R.Y.)
| | - Jiang-Yang Shao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; (J.-Y.S.); (Y.-W.Z.)
| | - Zhong-Liang Gong
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; (J.-Y.S.); (Y.-W.Z.)
| | - Yu-Wu Zhong
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; (J.-Y.S.); (Y.-W.Z.)
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