1
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Sun YF, Chen XL, Zhang DH, Huo P, Liu Z, Zhou L, Lin FL, Lu CZ. Efficient Deep-Blue Organic Light-Emitting Diodes Employing Doublet Sensitization. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2408118. [PMID: 39252676 DOI: 10.1002/adma.202408118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 08/22/2024] [Indexed: 09/11/2024]
Abstract
Fast and efficient exciton utilization is a crucial solution and highly desirable for achieving high-performance blue organic light-emitting diodes (OLEDs). However, the rate and efficiency of exciton utilization in traditional OLEDs, which employ fully closed-shell materials as emitters, are inevitably limited by spin statistical limitations and transition prohibition. Herein, a new sensitization strategy, namely doublet-sensitized fluorescence (DSF), is proposed to realize high-performance deep-blue electroluminescence. In the DSF-OLED, a doublet-emitting cerium(III) complex, Ce-2, is utilized as sensitizer for multi-resonance thermally activated delayed fluorescence emitter ν-DABNA. Experimental results reveal that holes and electrons predominantly recombine on Ce-2 to form doublet excitons, which subsequently transfer energy to the singlet state of ν-DABNA via exceptionally fast (over 108 s-1) and efficient (≈100%) Förster resonance energy transfer for deep-blue emission. Due to the circumvention of spin-flip in the DSF mechanism, near-unit exciton utilization efficiency and remarkably short exciton residence time of 1.36 µs are achieved in the proof-of-concept deep-blue DSF-OLED, which achieves a Commission Internationale de l'Eclairage coordinate of (0.13, 0.14), a high external quantum efficiency of 30.0%, and small efficiency roll-off of 14.7% at a luminance of 1000 cd m-2. The DSF device exhibits significantly improved operational stability compared with unsensitized reference device.
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Affiliation(s)
- Yu-Fu Sun
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, 341119, China
- School of Rare Earths, University of Science and Technology of China, Hefei, 230026, China
| | - Xu-Lin Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China
| | - Dong-Hai Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China
| | - Peihao Huo
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Beijing Engineering Technology Research Centre of Active Display, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Zhiwei Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Beijing Engineering Technology Research Centre of Active Display, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Liang Zhou
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
| | - Fu-Lin Lin
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China
| | - Can-Zhong Lu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, 341119, China
- School of Rare Earths, University of Science and Technology of China, Hefei, 230026, China
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2
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Zhang B, Wu C, Wu M, Wang Y, Luo M, Lei X, Gou L, Wu Z, Wang D, Zhang X. Ultralow Roll-off Thermally Activated Delayed Fluorescent Light-Emitting Diodes Based on Furo[2,3- b]quinoxaline Emitters. J Phys Chem Lett 2024:9431-9440. [PMID: 39248415 DOI: 10.1021/acs.jpclett.4c02363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2024]
Abstract
Herein, a Y-type compound (67dMeOTPA-FQ) and a T-type compound (58dMeOTPA-FQ) based on furo[2,3-b]quinoxaline were synthesized. The theory calculation shows the S1 and T1 of both compounds own a charge-transfer feature while their T2 states have a local excitation feature. The calculated kRISC(T2-S1) is one to 2 orders of magnitude larger than kRISC(T1-S1). Thus, the nonadiabatic spin-vibronic mechanism involved in the T2 state is suggested to be responsible for the thermally activated delayed fluorescence (TADF) feature. Meanwhile, when 2-methyl-9,10-bis(naphthalen-2-yl)anthracene is selected as host, the maximum luminance of the device based on 67dMeOTPA-FQ is up to 104215 cd·m-2, and the external quantum efficiency (EQE) keeps in the 8.2-8.0% range with the luminance changed from 55.0 cd·m-2 to 90000 cd·m-2, only 2.4% efficiency roll-off. As for 58dMeOTPA-FQ, a slightly lower EQE of 7.1-6.7% with the luminance range of 1-40000 cd·m-2 was achieved for orange-red emission. Both the reverse intersystem crossing (RISC) and triplet-triplet annihilation mechanisms are supposed to concurrently contribute to the utilization of triplet excitons and suppress the notorious efficiency roll-off observed in TADF-based devices.
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Affiliation(s)
- BoHua Zhang
- School of Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - ChuanMing Wu
- School of Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - MingXin Wu
- School of Materials Science and Engineering, Chang'an University, Xi'an 710061, P. R. China
| | - YeYang Wang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, P. R. China
| | - MeiTing Luo
- School of Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - XiaoLi Lei
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, P.R. China
| | - Lei Gou
- School of Materials Science and Engineering, Chang'an University, Xi'an 710061, P. R. China
| | - Zhaoxin Wu
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - DongDong Wang
- School of Chemistry, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - XinWen Zhang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, P. R. China
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3
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Stanitska M, Keruckiene R, Sini G, Volyniuk D, Marsalka A, Shi ZE, Liu CM, Lin YR, Chen CP, Grazulevicius JV. Exploring the Charge-Transport and Optical Characteristics of Organic Doublet Radicals: A Theoretical and Experimental Study with Photovoltaic Applications. ACS APPLIED MATERIALS & INTERFACES 2024; 16:41230-41243. [PMID: 39052450 PMCID: PMC11310911 DOI: 10.1021/acsami.4c08524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 07/16/2024] [Accepted: 07/19/2024] [Indexed: 07/27/2024]
Abstract
Herein, we present a series of stable radicals containing a trityl carbon-centered radical moiety exhibiting interesting properties. The radicals demonstrate the most blue-shifted anti-Kasha doublet emission reported so far with high color purity (full width at half-maximum of 46 nm) and relatively high photoluminescence quantum yields of deoxygenated toluene solutions reaching 31%. The stable radicals demonstrate equilibrated bipolar charge transport with charge mobility values reaching 10-4 cm2/V·s at high electric fields. The experimental results in combination with the results of TD-DFT calculations confirm that the blue emission of radicals violates the Kasha rule and originates from higher excited states, whereas the bipolar charge transport properties are found to stem from the particularity of radicals to involve the same molecular orbital(s) in electron and hole transport. The radicals act as the efficient materials for interlayers, passivating interfacial defects and enhancing charge extraction in PSCs. Consequently, this leads to outstanding performance of PSC, with power conversion efficiency surpassing 21%, accompanied by a remarkable increase in open-circuit voltage and exceptional stability.
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Affiliation(s)
- Mariia Stanitska
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254 Kaunas, Lithuania
| | - Rasa Keruckiene
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254 Kaunas, Lithuania
| | - Gjergji Sini
- Laboratoire
de Physicochimie des Polymères et des Interfaces, CY Paris Cergy Université, EA 2528, 5 mail Gay-Lussac, Cergy-Pontoise, Cedex 95031, France
| | - Dmytro Volyniuk
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254 Kaunas, Lithuania
| | - Arunas Marsalka
- Faculty
of Physics, Vilnius University, Sauletekio st. 9-3, LT-10222 Vilnius, Lithuania
| | - Zhong-En Shi
- Department
of Materials Engineering, Ming Chi University
of Technology, 84 Gunjuan
Road, Taishan, New Taipei City 24301, Taiwan, Republic of China
| | - Chung-Ming Liu
- Department
of Materials Engineering, Ming Chi University
of Technology, 84 Gunjuan
Road, Taishan, New Taipei City 24301, Taiwan, Republic of China
| | - Yan-Ru Lin
- Department
of Materials Engineering, Ming Chi University
of Technology, 84 Gunjuan
Road, Taishan, New Taipei City 24301, Taiwan, Republic of China
| | - Chih-Ping Chen
- Department
of Materials Engineering, Ming Chi University
of Technology, 84 Gunjuan
Road, Taishan, New Taipei City 24301, Taiwan, Republic of China
- College
of Engineering, Chang Gung University, Taoyuan City 33302, Taiwan, Republic of
China
| | - Juozas V. Grazulevicius
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254 Kaunas, Lithuania
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Khalilian MH, DiLabio GA. Non-Aufbau electronic structure in radical enzymes and control of the highly reactive intermediates. Chem Sci 2024; 15:11865-11874. [PMID: 39092113 PMCID: PMC11290419 DOI: 10.1039/d4sc01785d] [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: 03/16/2024] [Accepted: 06/07/2024] [Indexed: 08/04/2024] Open
Abstract
Radicals are highly reactive, short-lived chemical species that normally react indiscriminately with biological materials, and yet, nature has evolved thousands of enzymes that employ radicals to catalyze thermodynamically challenging chemistry. How these enzymes harness highly reactive radical intermediates to steer the catalysis to the correct outcome is a topic of intense investigation. Here, the results of detailed QM/MM calculations on archetype radical B12-enzymes are presented that provide new insights into how these enzymes control the reactivity of radicals within their active sites. The catalytic cycle in B12-enzymes is initiated through the formation of the 5'-deoxyadenosyl (Ado˙) moiety, a primary carbon-centred radical, which must migrate up to 8 Å to reach the target substrate to engage in the next step of the catalytic process, a hydrogen atom abstraction. Our calculations reveal that Ado˙ within the protein environment exhibits an unusual non-Aufbau electronic structure in which the singly occupied molecular orbital is lower in energy than the doubly occupied orbitals, an uncommon phenomenon known as SOMO-HOMO inversion (SHI). We find that the magnitude of SHI in the initially formed Ado˙ is larger compared to when the Ado˙ is near the intended substrate, leading to the former being relatively less reactive. The modulation of the SHI originates from Coulombic interactions of a quantum nature between a negative charge on a conserved glutamate residue and the spin on the Ado˙. Our findings support a novel hypothesis that these enzymes utilize this quantum Coulombic effect as a means of maintaining exquisite control over the chemistry of highly reactive radical intermediates in enzyme active sites.
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Affiliation(s)
- M Hossein Khalilian
- Department of Chemistry, The University of British Columbia 3247 University Way Kelowna British Columbia V1V 1V7 Canada +1-250-807-6617
| | - Gino A DiLabio
- Department of Chemistry, The University of British Columbia 3247 University Way Kelowna British Columbia V1V 1V7 Canada +1-250-807-6617
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5
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Yu CP, Chowdhury R, Fu Y, Ghosh P, Zeng W, Mustafa TBE, Grüne J, Walker LE, Congrave DG, Chua XW, Murto P, Rao A, Sirringhaus H, Plasser F, Grey CP, Friend RH, Bronstein H. Near-infrared luminescent open-shell π-conjugated systems with a bright lowest-energy zwitterionic singlet excited state. SCIENCE ADVANCES 2024; 10:eado3476. [PMID: 39047089 PMCID: PMC11268402 DOI: 10.1126/sciadv.ado3476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 06/20/2024] [Indexed: 07/27/2024]
Abstract
Open-shell systems with extensive π-conjugation have fascinating properties due to their narrow bandgaps and spin interactions. In this work, we report neutral open-shell di- and polyradical conjugated materials exhibiting intriguing optical and magnetic properties. Our key design advance is the planarized geometry allowing for greater interaction between adjacent spins. This results in absorption and emission in the near infrared at 803 and 1050 nanometers, respectively, and we demonstrate a unique electronic structure where a bright zwitterionic excited state is the lowest-accessible electronic transition. Electron paramagnetic resonance spectroscopy and superconducting quantum interference device measurements reveal that our materials are open-shell singlets with different degrees of spin interactions, dynamics, and antiferromagnetic properties, which likely contributed to the formation of their emissive zwitterionic singlet excited state and near-infrared emission. In addition, our materials show reversible and stable electrochromic switching with more than 500 cycles, indicating their potential for optoelectronic and electrochemical energy storage applications.
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Affiliation(s)
- Craig P. Yu
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Rituparno Chowdhury
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Yao Fu
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Pratyush Ghosh
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Weixuan Zeng
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Tarig B. E. Mustafa
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Jeannine Grüne
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Lucy E. Walker
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Daniel G. Congrave
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Xian Wei Chua
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Petri Murto
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Akshay Rao
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Henning Sirringhaus
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Felix Plasser
- Department of Chemistry, Loughborough University, Loughborough, LE11 3TU, UK
| | - Clare P. Grey
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Richard H. Friend
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
| | - Hugo Bronstein
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK
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6
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Lv L, Zhang Y, Ning Z. Deciphering the doublet luminescence mechanism in neutral organic radicals: spin-exchange coupling, reversed-quartet mechanism, excited-state dynamics. RSC Adv 2024; 14:23987-23999. [PMID: 39086516 PMCID: PMC11289762 DOI: 10.1039/d4ra03566f] [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: 05/15/2024] [Accepted: 07/17/2024] [Indexed: 08/02/2024] Open
Abstract
Neutral organic radical molecules have recently attracted considerable attention as promising luminescent and quantum-information materials. However, the presence of a radical often shortens their excited-state lifetime and results in fluorescence quenching due to enhanced intersystem crossing (EISC). Recently, an experimental report introduced an efficient luminescent radical molecule, tris(2,4,6-trichlorophenyl)methyl-carbazole-anthracene (TTM-1Cz-An). In this study, we systematically performed quantum theoretical calculations combined with the path integral approach to quantitatively calculate the excited-state dynamics processes and spectral characteristics. Our theoretical findings suggest that the sing-doublet D1 state, originating from the anthracene excited singlet state, is quickly converted to the doublet (trip-doublet) state via EISC, facilitated by a significant nonequivalence exchange interaction, with ΔJ ST = 0.174 cm-1. The formation of the quartet state (Q1, trip-quartet) was predominantly dependent on the exchange coupling 3/2J TR = 0.086 cm-1 between the triplet spin electrons of anthracene and the TTM-1Cz radical. Direct spin-orbit coupling ISC to the Q1 state was minimal due to the nearly identical spatial wavefunctions of the and Q1 levels. The effective occurrence of reverse intersystem crossing (RISC) from the Q1 to D1 state is a critical step in controlling the luminescence of TTM-1Cz-An. The calculated RISC rate k RISC, including the Herzberg-Teller effect, was 3.64 × 105 s-1 at 298 K, significantly exceeding the phosphorescence and nonradiative rates of the Q1 state, thus enabling the D1 repopulation. Subsequently, a strong electronic coupling of 37.4 meV was observed between the D1 and D2 states, along with a dense manifold of doublet states near the D1 state energy, resulting in a larger reverse internal conversion rate k RIC of 9.26 × 1010 s-1. Distributed to the D2 state, the obtained emission rate of k f = 2.98-3.18 × 107 s-1 was in quite good agreement with the experimental value of 1.28 × 107 s-1, and its temperature effect was not remarkable. Our study not only provides strong support for the experimental findings but also offers valuable insights for the molecular design of high-efficiency radical emitters.
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Affiliation(s)
- LingLing Lv
- School of Chemical Engineering and Technology, Tianshui Normal University Tianshui Gansu 741001 China /
- Key Laboratory of Advanced Optoelectronic Functional Materials of Gansu Province, Tianshui Normal University Tianshui Gansu 741001 China
| | - YanYing Zhang
- School of Chemical Engineering and Technology, Tianshui Normal University Tianshui Gansu 741001 China /
| | - ZiYe Ning
- School of Chemical Engineering and Technology, Tianshui Normal University Tianshui Gansu 741001 China /
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7
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Anraku K, Matsuda K, Miyata S, Ishii H, Hosokai T, Okada S, Nakamura K, Nakao K, Albrecht K. A water-soluble luminescent tris(2,4,6-trichlorophenyl)methyl radical-carbazole dyad. J Mater Chem B 2024; 12:6840-6846. [PMID: 38913346 DOI: 10.1039/d4tb00940a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Organic luminescent radicals are a new class of materials with potential applications not only in light-emitting devices but also in the biochemistry field. New tris(2,4,6-trichlorophenyl)methyl (TTM) radicals with alkoxy-substituted carbazole donors were synthesized and characterized. PEG-substituted carbazole-TTM was found to be water-soluble. The water-soluble TTM radical aqueous solution showed fluorescence at 777 nm and the ability to shorten the longitudinal relaxation time (T1) of water. The concept of water-soluble luminescent radicals is expected to be used to develop a potential fluorescence and MR dual-use imaging moiety.
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Affiliation(s)
- Kosuke Anraku
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga-Shi, Fukuoka 816-8580, Japan
| | - Kenshiro Matsuda
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga-Shi, Fukuoka 816-8580, Japan
| | - Satoshi Miyata
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Hikaru Ishii
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Takuya Hosokai
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Satoshi Okada
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan
| | - Kazuhiro Nakamura
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga-Shi, Fukuoka 816-8580, Japan
| | - Kohei Nakao
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-Koen, Kasuga-Shi, Fukuoka 816-8580, Japan.
| | - Ken Albrecht
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-Koen, Kasuga-Shi, Fukuoka 816-8580, Japan.
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8
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Liu X, Shi C, Zhao M, Li F, Zhang J, Jiang Z, Li Q, Yuan A, Yan H. Robust Radicals Featuring B- and N-Embedded Dioxygen-Bridged Units: Synthesis, Structures, and Optical Properties. Chemistry 2024; 30:e202400927. [PMID: 38773816 DOI: 10.1002/chem.202400927] [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: 03/05/2024] [Revised: 05/18/2024] [Accepted: 05/21/2024] [Indexed: 05/24/2024]
Abstract
Tris(2,4,6-trichlorophenyl)methyl (TTM) group has been widely used for constructing organic radicals, but the poor optical stabilities limit the application prospects of the TTM radicals. In this work, the rigid B- and N-embedded dioxygen-bridged (BO and NO) units were attached to the TTM skeleton as the strong electron-withdrawing and electron-donating groups, respectively. The rigidity and strong electronic effect of the BO and NO units contribute to the high chemical and optical stability of BO-TTM and NO-TTM radicals. Notably, NO-TTM exhibits near-infrared emission at 830 nm with a narrow full width at half maximum (FWHM) of 55 nm (100 meV), while BO-TTM shows blue-shifted luminescence at 635 nm and a narrower FWHM of merely 43 nm (130 meV). This study has developed a methodology to produce highly efficient and enduring luminescent radicals, which could tune emission properties such as wavelength and FWHM.
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Affiliation(s)
- Xinyu Liu
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Chao Shi
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Meng Zhao
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Feiyang Li
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Jing Zhang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Zhen Jiang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Qiuxia Li
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Aihua Yuan
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, 212100, Zhenjiang, Jiangsu, PR China
| | - Hong Yan
- State Key Laboratory of Coordination Chemistry, Nanjing University, 210093, Nanjing, P. R. China
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9
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Mizuno A, Matsuoka R, Kimura S, Ochiai K, Kusamoto T. Spin-Correlated Luminescence of a Carbazole-Containing Diradical Emitter: Single-Molecule Magnetoluminescence and Thermally Activated Emission. J Am Chem Soc 2024; 146:18470-18483. [PMID: 38921686 DOI: 10.1021/jacs.4c03972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Luminescent radicals have been intensively studied as a new class of materials exhibiting novel photofunctions unique to open-shell systems. When luminescent radicals are assembled, intriguing spin-correlated luminescence phenomena emerge, including excimer-like emission and magnetic-field effects on luminescence (i.e., magnetoluminescence, MagLum). However, the underlying mechanisms of these phenomena arising from spin multiplicity and spin-dependent excited-state dynamics are poorly understood due to the limited number of luminescent polyradical systems available for study. In particular, the correlation between stronger intramolecular exchange interactions (|2J/kB| > ∼10 K, where J and kB are the intramolecular exchange coupling constant and the Boltzmann constant, respectively) and luminescence properties has not been fully explained. In this study, a novel carbazole-containing diradical emitter (1) and the corresponding monoradical (2) were prepared for the in-depth study of spin-correlated luminescence properties, with luminescence measurements under magnetic fields of up to 18 T. Diradical 1 has a negative 2J/kB value of several tens of kelvin and exhibits a single-molecule MagLum and thermally activated luminescence, whereas 2 does not. Detailed quantitative analyses revealed that both the spin-correlated luminescence properties of 1 are strongly dominated by ground-state spin statistics based on the Boltzmann distribution (i.e., 2J/kB values). Furthermore, diradical 1 exhibits external heavy-atom effects in heavy-atom-containing solvents such as iodobenzene, whereas monoradical 2 does not. This is the first experimental verification of external heavy-atom effects in polyradical emitters. This work demonstrates that polyradical emitters can be designed based on spin degrees of freedom in both ground and excited states.
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Affiliation(s)
- Asato Mizuno
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
- Division of Chemistry, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Ryota Matsuoka
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
- Division of Chemistry, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa 240-0193, Japan
| | - Shojiro Kimura
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Keisuke Ochiai
- SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa 240-0193, Japan
| | - Tetsuro Kusamoto
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
- Division of Chemistry, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa 240-0193, Japan
- JST-PRESTO, 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Japan
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10
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Gu Q, Gorgon S, Romanov AS, Li F, Friend RH, Evans EW. Fast Transfer of Triplet to Doublet Excitons from Organometallic Host to Organic Radical Semiconductors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2402790. [PMID: 38819637 DOI: 10.1002/adma.202402790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 05/09/2024] [Indexed: 06/01/2024]
Abstract
Spin triplet exciton formation sets limits on technologies using organic semiconductors that are confined to singlet-triplet photophysics. In contrast, excitations in the spin doublet manifold in organic radical semiconductors can show efficient luminescence. Here the dynamics of the spin allowed process of intermolecular energy transfer from triplet to doublet excitons are explored. A carbene-metal-amide (CMA-CF3) is employed as a model triplet donor host, since following photoexcitation it undergoes extremely fast intersystem crossing to generate a population of triplet excitons within 4 ps. This enables a foundational study for tracking energy transfer from triplets to a model radical semiconductor, TTM-3PCz. Over 74% of all radical luminescence originates from the triplet channel in this system under photoexcitation. It is found that intermolecular triplet-to-doublet energy transfer can occur directly and rapidly, with 12% of triplet excitons transferring already on sub-ns timescales. This enhanced triplet harvesting mechanism is utilized in efficient near-infrared organic light-emitting diodes, which can be extended to other opto-electronic and -spintronic technologies by radical-based spin control in molecular semiconductors.
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Affiliation(s)
- Qinying Gu
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
- Shanghai Artificial Intelligence Laboratory, Shanghai, 200232, P. R. China
| | - Sebastian Gorgon
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Alexander S Romanov
- Department of Chemistry, University of Manchester, Oxford Rd., Manchester, M13 9PL, UK
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Qianjin Avenue 2699, Changchun, 130012, P. R. China
| | - Richard H Friend
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Emrys W Evans
- Department of Chemistry, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
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11
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Cho HH, Gorgon S, Londi G, Giannini S, Cho C, Ghosh P, Tonnelé C, Casanova D, Olivier Y, Baikie TK, Li F, Beljonne D, Greenham NC, Friend RH, Evans EW. Efficient near-infrared organic light-emitting diodes with emission from spin doublet excitons. NATURE PHOTONICS 2024; 18:905-912. [PMID: 39247521 PMCID: PMC11374703 DOI: 10.1038/s41566-024-01458-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 05/07/2024] [Indexed: 09/10/2024]
Abstract
The development of luminescent organic radicals has resulted in materials with excellent optical properties for near-infrared emission. Applications of light generation in this range span from bioimaging to surveillance. Although the unpaired electron arrangements of radicals enable efficient radiative transitions within the doublet-spin manifold in organic light-emitting diodes, their performance is limited by non-radiative pathways introduced in electroluminescence. Here we present a host-guest design for organic light-emitting diodes that exploits energy transfer with up to 9.6% external quantum efficiency for 800 nm emission. The tris(2,4,6-trichlorophenyl)methyl-triphenyl-amine radical guest is energy-matched to the triplet state in a charge-transporting anthracene-derivative host. We show from optical spectroscopy and quantum-chemical modelling that reversible host-guest triplet-doublet energy transfer allows efficient harvesting of host triplet excitons.
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Affiliation(s)
- Hwan-Hee Cho
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Giacomo Londi
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
- Present Address: Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy
| | - Samuele Giannini
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, Belgium
- Present Address: Institute of Chemistry of OrganoMetallic Compounds, National Research Council (ICCOM-CNR), Pisa, Italy
| | - Changsoon Cho
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
- Institute for Convergence Research and Education in Advanced Technology, Yonsei University, Seoul, Republic of Korea
| | - Pratyush Ghosh
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Claire Tonnelé
- Donostia International Physics Centre, Donostia, Spain
- Ikerbasque Foundation for Science, Bilbao, Spain
| | - David Casanova
- Donostia International Physics Centre, Donostia, Spain
- Ikerbasque Foundation for Science, Bilbao, Spain
| | - Yoann Olivier
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
| | - Tomi K Baikie
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, Belgium
| | - Neil C Greenham
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Emrys W Evans
- Department of Chemistry, Swansea University, Swansea, UK
- Centre for Integrative Semiconductor Materials, Swansea University, Swansea, UK
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12
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Gou Q, Guan J, Zhang L, Ai X. Phenyl Derivatives Modulate the Luminescent Properties and Stability of CzBTM-Type Radicals. Molecules 2024; 29:2900. [PMID: 38930965 PMCID: PMC11206717 DOI: 10.3390/molecules29122900] [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: 05/21/2024] [Revised: 06/15/2024] [Accepted: 06/16/2024] [Indexed: 06/28/2024] Open
Abstract
The distinctive electron structures of luminescent radicals offer considerable potential for a diverse array of applications. Up to now, the luminescent properties of radicals have been modulated through the introduction of electron-donating substituents, predominantly derivatives of carbazole and polyaromatic amines with more and more complicated structures and redshifted luminescent spectra. Herein, four kinds of (N-carbazolyl)bis(2,4,6-tirchlorophenyl)-methyl (CzBTM) radicals, Ph2CzBTM, Mes2CzBTM, Ph2PyIDBTM, and Mes2PyIDBTM, were synthesized and characterized by introducing simple phenyl and 2,4,6-trimethylphenyl groups to CzBTM and PyIDBTM. These radicals exhibit rare blueshifted emission spectra compared to their parent radicals. Furthermore, modifications to CzBTM significantly enhanced the photoluminescence quantum yields (PLQYs), with a highest PLQY of 21% for Mes2CzBTM among CzBTM-type radicals. Additionally, the molecular structures, photophysical properties of molecular orbitals, and stability of the four radicals were systematically investigated. This study provides a novel strategy for tuning the luminescent color of radicals to shorter wavelengths and improving thermostability.
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Affiliation(s)
- Quanquan Gou
- School of Materials Science and Engineering, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
| | - Jiahao Guan
- School of Materials Science and Engineering, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
| | - Lintao Zhang
- School of Materials Science and Engineering, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
- Collaborative Innovation Center of Marine Science and Technology, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
| | - Xin Ai
- School of Materials Science and Engineering, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
- Collaborative Innovation Center of Marine Science and Technology, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
- Collaborative Innovation Center of Information Technology, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
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13
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Mishra S, Vilas-Varela M, Fatayer S, Albrecht F, Peña D, Gross L. Observation of SOMO-HOMO Inversion in a Neutral Polycyclic Conjugated Hydrocarbon. ACS NANO 2024; 18:15898-15904. [PMID: 38833667 PMCID: PMC11191738 DOI: 10.1021/acsnano.4c03257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 05/17/2024] [Accepted: 05/24/2024] [Indexed: 06/06/2024]
Abstract
We report the generation of a nonbenzenoid polycyclic conjugated hydrocarbon, which consists of a biphenyl moiety substituted by indenyl units at the 4,4' positions, on ultrathin sodium chloride films by tip-induced chemistry. Single-molecule characterization by scanning tunneling and atomic force microscopy reveals an open-shell biradical ground state with a peculiar electronic configuration wherein the singly occupied molecular orbitals (SOMOs) are lower in energy than the highest occupied molecular orbital (HOMO).
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Affiliation(s)
| | - Manuel Vilas-Varela
- Center
for Research in Biological Chemistry and Molecular Materials (CiQUS)
and Department of Organic Chemistry, University
of Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Shadi Fatayer
- Applied
Physics Program, Physical Science and Engineering Division, King Abdullah University of Science and Technology
(KAUST), Thuwal 23955-6900, Kingdom
of Saudi Arabia
| | | | - Diego Peña
- Center
for Research in Biological Chemistry and Molecular Materials (CiQUS)
and Department of Organic Chemistry, University
of Santiago de Compostela, Santiago de Compostela 15782, Spain
- Oportunius, Galician
Innovation Agency (GAIN), Santiago
de Compostela 15702, Spain
| | - Leo Gross
- IBM
Research Europe − Zurich, Rüschlikon 8803, Switzerland
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14
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Zhang Z, Xiong Z, Zhang J, Chu B, Liu X, Tu W, Wang L, Sun JZ, Zhang C, Zhang H, Zhang X, Tang BZ. Near-Infrared Emission Beyond 900 nm from Stable Radicals in Nonconjugated Poly(diphenylmethane). Angew Chem Int Ed Engl 2024; 63:e202403827. [PMID: 38589299 DOI: 10.1002/anie.202403827] [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: 02/23/2024] [Revised: 03/29/2024] [Accepted: 04/07/2024] [Indexed: 04/10/2024]
Abstract
Organic radicals with narrow energy gaps are highly sought-after for the production of near-infrared (NIR) fluorophores. However, the current repertoire of developed organic radicals is notably limited, facing challenges related to stability and low fluorescence efficiency. This study addresses these limitations by achieving stable radicals in nonconjugated poly(diphenylmethane) (PDPM). Notably, PDPM exhibits a well-balanced structural flexibility and rigidity, resulting in a robust intra-/inter-chain through-space conjugation (TSC). The stable radicals within PDPM, coupled with strong TSC, yield a remarkable full-spectrum emission spanning from blue to NIR beyond 900 nm. This extensive tunability is achieved through careful adjustments of concentration and excitation wavelength. The findings highlight the efficacy of polymerization in stabilizing radicals and introduce a novel approach for developing nonconjugated NIR emitters based on triphenylmethane subunits.
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Affiliation(s)
- Ziteng Zhang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Motor Vehicle Biofuel Technology, International Research Center for X Polymers, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Zuping Xiong
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Jianyu Zhang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction and Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong, 999077, China
| | - Bo Chu
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Motor Vehicle Biofuel Technology, International Research Center for X Polymers, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
| | - Xiong Liu
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Motor Vehicle Biofuel Technology, International Research Center for X Polymers, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Weihao Tu
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Lei Wang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Jing Zhi Sun
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
- Centre of Healthcare Materials, Shaoxing Institute, Zhejiang University, Shaoxing, 312000, China
| | - Chengjian Zhang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Motor Vehicle Biofuel Technology, International Research Center for X Polymers, Zhejiang University, Hangzhou, 310058, China
| | - Haoke Zhang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310058, China
- Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
- Centre of Healthcare Materials, Shaoxing Institute, Zhejiang University, Shaoxing, 312000, China
| | - Xinghong Zhang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Motor Vehicle Biofuel Technology, International Research Center for X Polymers, Zhejiang University, Hangzhou, 310058, China
| | - Ben Zhong Tang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction and Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong, 999077, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
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15
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Li P, Bai F. A Thorough Examination of the Variables Affecting the Quantum Efficiency of Radiative Decay of Trichlorotriphenylmethyl Radicals. J Phys Chem A 2024; 128:4279-4287. [PMID: 38752807 DOI: 10.1021/acs.jpca.4c01779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Fluorescence quantum efficiency is determined by the competition between radiation and nonradiation processes of the excited states. Understanding the factors affecting the radiation and nonradiative decay rates is of great significance for the design of luminescent materials. The excitation state deactivation mechanisms of singlet and triplet states have been extensively studied, providing a comprehensive understanding of the processes involved in the relaxation of these states. However, research on free radical systems involving doublet states is relatively scarce. Therefore, in this study, radiation and nonradiative decay rates and the mechanism of a series of trichlorotriphenylmethyl-based radicals were investigated theoretically. The results indicate that the relative rotations of electron donor and acceptor, as well as the internal rotations of trichlorotriphenylmethyl moiety, play important roles in energy dissipation through nonradiative channels. The effect of a solid-state environment on the radiation and nonradiative decay rates of radicals was investigated using a combination of quantum mechanics and molecular mechanics methods. The results indicate that the solid-state environment restricts the expansion of the conjugated system in the excited state of radicals, leading to a slight decrease in radiative decay rate. In addition, the solid-state environment reduces the reorganization energy and also affects the adiabatic excitation energy of radicals. The reduction in reorganization energy results in a decrease in nonradiative rate, while the opposite effect is observed for adiabatic excitation energy. The nonradiative rate of radicals in a solid-state environment is thus inflected by a combination of molecular geometric structure relaxation and ground-excited state energy gap.
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Affiliation(s)
- Pengyuan Li
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry and College of Chemistry, Jilin University, Changchun 130021, P. R. China
| | - Fuquan Bai
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry and College of Chemistry, Jilin University, Changchun 130021, P. R. China
- State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China
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16
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She P, Qin Y, Zhou Y, Zheng X, Li F, Liu S, Ma Y, Zhao Q, Wong WY. Photoactivated Circularly Polarized Luminescent Organic Radicals in Doped Amorphous Polymer. Angew Chem Int Ed Engl 2024; 63:e202403660. [PMID: 38465907 DOI: 10.1002/anie.202403660] [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: 02/21/2024] [Accepted: 03/08/2024] [Indexed: 03/12/2024]
Abstract
Luminescent organic radicals, especially those with photoactivated circularly polarized luminescence (CPL) features, hold great significance for cutting-edge optoelectronic applications, but their development still remains a challenge. In this study, we propose a novel strategy to achieve photoactivated CPL radicals by bonding two phosphine centers within an axial chiral system, yielding a compound of R/S-5,5-bis(diphenylphosphino)-4,4'-bibenzo[d][1,3]dioxole (R/S-BDP). The photoactivated R/S-BDP molecules in polymer matrix display a robust quantum yield of 19.8 % and a dissymmetry factor (glum) of 1.2×10-4, marking this work as the first example of photoactivated CPL radicals. Furthermore, the glum is improved to 1.0×10-2 by using a liquid crystal as host. Experimental and theoretical analyses reveal that R/S-BDP molecules, endowed with double phosphine cores in axial chirality, offer a direct way for intramolecular electron transfer upon photoirradiation. This leads to the generation of radical ionic pairs, which subsequently trigger the donor-acceptor arrangement through intermolecular electron transfer, thereby resulting in stable radical emission. The extended photoactivated BDP-F exhibits a remarkably high quantum efficiency of 57.8%. Ultimately, the distinctive photo-responsive CPL radical luminescence has been successfully used for information displays and anti-counterfeiting.
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Affiliation(s)
- Pengfei She
- Department of Applied Biology and Chemical Technology, Research Institute for Smart Energy., The Hong Kong Polytechnic University, Hung Hom, Hong Kong, P. R. China
- The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen, 518057, P. R. China
| | - Yanyan Qin
- Department of Applied Biology and Chemical Technology, Research Institute for Smart Energy., The Hong Kong Polytechnic University, Hung Hom, Hong Kong, P. R. China
- The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen, 518057, P. R. China
| | - Yuxiang Zhou
- State Key Laboratory of Organic Electronics and Information Displays &, Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM) &, Institute of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Xiaokang Zheng
- Department of Applied Biology and Chemical Technology, Research Institute for Smart Energy., The Hong Kong Polytechnic University, Hung Hom, Hong Kong, P. R. China
- The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen, 518057, P. R. China
| | - Feiyang Li
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212100, P. R. China
| | - Shujuan Liu
- State Key Laboratory of Organic Electronics and Information Displays &, Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM) &, Institute of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Yun Ma
- State Key Laboratory of Organic Electronics and Information Displays &, Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM) &, Institute of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Qiang Zhao
- State Key Laboratory of Organic Electronics and Information Displays &, Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM) &, Institute of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Wai-Yeung Wong
- Department of Applied Biology and Chemical Technology, Research Institute for Smart Energy., The Hong Kong Polytechnic University, Hung Hom, Hong Kong, P. R. China
- The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen, 518057, P. R. China
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17
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Murto P, Li B, Fu Y, Walker LE, Brown L, Bond AD, Zeng W, Chowdhury R, Cho HH, Yu CP, Grey CP, Friend RH, Bronstein H. Steric Control of Luminescence in Phenyl-Substituted Trityl Radicals. J Am Chem Soc 2024; 146:13133-13141. [PMID: 38695282 PMCID: PMC11099960 DOI: 10.1021/jacs.4c00292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 05/16/2024]
Abstract
Triphenylmethyl (trityl) radicals have shown potential for use in organic optoelectronic applications, but the design of practical trityl structures has been limited to donor/radical charge-transfer systems due to the poor luminescence of alternant symmetry hydrocarbons. Here, we circumvent the symmetry-forbidden transition of alternant hydrocarbons via excited-state symmetry breaking in a series of phenyl-substituted tris(2,4,6-trichlorophenyl)methyl (TTM) radicals. We show that 3-fold phenyl substitution enhances the emission of the TTM radical and that steric control modulates the optical properties in these systems. Simple ortho-methylphenyl substitution boosts the photoluminescence quantum efficiency from 1% (for TTM) to 65% at a peak wavelength of 612 nm (for 2-T3TTM) in solution. In the crystalline solid state, the neat 2-T3TTM radical shows a remarkably high photoluminescence quantum efficiency of 25% for emission peaking at 706 nm. This has implications in the design of aryl-substituted radical structures where the electronic coupling of the substituents influences variables such as emission, charge transfer, and spin interaction.
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Affiliation(s)
- Petri Murto
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Biwen Li
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Yao Fu
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Lucy E. Walker
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Laura Brown
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Andrew D. Bond
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Weixuan Zeng
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | | | - Hwan-Hee Cho
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Craig P. Yu
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Clare P. Grey
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Richard H. Friend
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Hugo Bronstein
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
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18
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Sakamaki T, Zhang Y, Fukuma S, Cruz CM, Valdivia AC, Campaña AG, Casado J, Shang R, Nakamura E. Doubly Spiro-Conjugated Chiral Carbocycles Exhibiting SOMO-HOMO Inversion in Persistent Radical Cations. J Am Chem Soc 2024; 146:12712-12722. [PMID: 38655573 DOI: 10.1021/jacs.4c02404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Persistent chiral organic open-shell systems have captured growing interest due to their potential applications in organic spintronic and optoelectronic devices. Nevertheless, the integration of configurationally stable chirality into an organic open-shell system continues to pose challenges in molecular design. The π-extended skeleton incorporated in spiro-conjugated carbocycles can provide robust chiroptical properties and a significant stabilization of the excited and ionic radical states. However, this approach has been relatively less explored in the design of persistent organic open-shell systems. We report here the (S,S)-, (R,R)-, and meso-isomers of doubly spiro-conjugated carbocycles featuring flat and rigid carbon-bridged para-phenylenevinylene (CPV) of different conjugation lengths connected by two spiro-carbon centers, which we denote D-spiro-CPV for its quasi-dimeric structure. Our synthetic method based on a double lithiation cyclization approach enables facile production of D-spiro-CPV. D-spiro-CPVs exhibit circularly polarized luminescence (CPL) with high fluorescence quantum yields (ΦFL) resulting in a high CPL brightness of 21 M-1 cm-1 and also exhibit high thermal and photostability. The monoradical cation of D-spiro-CPV absorbing near-infrared light is notably persistent, exhibiting a half-life of 570 h under ambient conditions due to doubly spiro-conjugative stabilization. Theoretical and electrochemical studies indicate the radical cation of D-spiro-CPVs presents a non-Aufbau electron filling, exhibiting inversion of the energy level of the singly occupied molecular orbital (SOMO) and the highest (doubly) occupied molecular orbitals with the SOMO level even below the HOMO-1 level (double SHI effect). Our discoveries provide valuable insights into non-Aufbau molecules and the development of configurationally stable, optically active persistent radicals.
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Affiliation(s)
- Takumi Sakamaki
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yan Zhang
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Shota Fukuma
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Carlos M Cruz
- Departamento de Química Orgánica, Facultad de Ciencias, Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Universidad de Granada (UGR), Avenida Fuente Nueva s/n, 18071 Granada, Spain
| | - Abel Cárdenas Valdivia
- Department of Physical Chemistry, Faculty of Science, University of Málaga, Campus de Teatinos, s/n, 29071 Málaga, Spain
| | - Araceli G Campaña
- Departamento de Química Orgánica, Facultad de Ciencias, Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ), Universidad de Granada (UGR), Avenida Fuente Nueva s/n, 18071 Granada, Spain
| | - Juan Casado
- Department of Physical Chemistry, Faculty of Science, University of Málaga, Campus de Teatinos, s/n, 29071 Málaga, Spain
| | - Rui Shang
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Eiichi Nakamura
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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19
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Han Z, Liu R, Zhang L, Song J, Bai Y, Lu X. Bright Luminescence of Free Radical TEMPO Enabled by Electrochemiluminescence Technique. Anal Chem 2024; 96:7304-7310. [PMID: 38651947 DOI: 10.1021/acs.analchem.4c01411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Radicals can feature theoretically 100% light utilization owing to their nonelectron spin-forbidden transition and represent the most advanced luminescent materials at present. 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) acts as a typically stable radical with very broad applications. However, their luminescent properties have not been discovered to date. In the present work, we observed the bright electrochemiluminescence (ECL) emission of TEMPO with a higher efficiency (72.3%) via the electrochemistry and coreactant strategies for the first time. Moreover, the radical-based ECL achieved high detection toward boron acid with a lower limit of detection (LOD) of 1.9 nM. This study offers a new approach to generate emissions for some unconventional luminophores and makes a major breakthrough in the field of new luminescent materials as well.
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Affiliation(s)
- Zhengang Han
- Key Laboratory of Water Environment Protection in Plateau Intersection (Ministry of Education), Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
| | - Ruirui Liu
- Key Laboratory of Water Environment Protection in Plateau Intersection (Ministry of Education), Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
| | - Lijun Zhang
- Key Laboratory of Water Environment Protection in Plateau Intersection (Ministry of Education), Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
| | - Jiangyun Song
- Key Laboratory of Water Environment Protection in Plateau Intersection (Ministry of Education), Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
| | - Yunfeng Bai
- Key Laboratory of Water Environment Protection in Plateau Intersection (Ministry of Education), Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
| | - Xiaoquan Lu
- Key Laboratory of Water Environment Protection in Plateau Intersection (Ministry of Education), Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
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20
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Ghosh P, Alvertis AM, Chowdhury R, Murto P, Gillett AJ, Dong S, Sneyd AJ, Cho HH, Evans EW, Monserrat B, Li F, Schnedermann C, Bronstein H, Friend RH, Rao A. Decoupling excitons from high-frequency vibrations in organic molecules. Nature 2024; 629:355-362. [PMID: 38720042 PMCID: PMC11078737 DOI: 10.1038/s41586-024-07246-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 02/27/2024] [Indexed: 05/12/2024]
Abstract
The coupling of excitons in π-conjugated molecules to high-frequency vibrational modes, particularly carbon-carbon stretch modes (1,000-1,600 cm-1) has been thought to be unavoidable1,2. These high-frequency modes accelerate non-radiative losses and limit the performance of light-emitting diodes, fluorescent biomarkers and photovoltaic devices. Here, by combining broadband impulsive vibrational spectroscopy, first-principles modelling and synthetic chemistry, we explore exciton-vibration coupling in a range of π-conjugated molecules. We uncover two design rules that decouple excitons from high-frequency vibrations. First, when the exciton wavefunction has a substantial charge-transfer character with spatially disjoint electron and hole densities, we find that high-frequency modes can be localized to either the donor or acceptor moiety, so that they do not significantly perturb the exciton energy or its spatial distribution. Second, it is possible to select materials such that the participating molecular orbitals have a symmetry-imposed non-bonding character and are, thus, decoupled from the high-frequency vibrational modes that modulate the π-bond order. We exemplify both these design rules by creating a series of spin radical systems that have very efficient near-infrared emission (680-800 nm) from charge-transfer excitons. We show that these systems have substantial coupling to vibrational modes only below 250 cm-1, frequencies that are too low to allow fast non-radiative decay. This enables non-radiative decay rates to be suppressed by nearly two orders of magnitude in comparison to π-conjugated molecules with similar bandgaps. Our results show that losses due to coupling to high-frequency modes need not be a fundamental property of these systems.
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Affiliation(s)
- Pratyush Ghosh
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Antonios M Alvertis
- KBR, Inc., NASA Ames Research Center, Moffett Field, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Petri Murto
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Shengzhi Dong
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
| | | | - Hwan-Hee Cho
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Emrys W Evans
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Department of Chemistry, Swansea University, Swansea, UK
| | - Bartomeu Monserrat
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
| | | | - Hugo Bronstein
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
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21
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Hattori Y, Yamamoto K, Kitajima R, Uchida K. Bright Fluorescent p-Phenylene-bridged Triarylmethyl Highly Stable Diradical. Chemistry 2024; 30:e202304124. [PMID: 38380885 DOI: 10.1002/chem.202304124] [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: 12/11/2023] [Revised: 02/13/2024] [Accepted: 02/19/2024] [Indexed: 02/22/2024]
Abstract
Two units of highly stable luminescent triarylmethyl radical, (3,5-dichloro-4-pyridyl)bis(2,4,6-trichlorophenyl)methyl radical (PyBTM), were bridged by p-phenylene linker. The photoluminescence quantum yield (PLQY) of PyBTM-PhPyBTM was at most 0.4 % in various organic solvents. Adding two mesityl groups on the terminals did not improve the PLQY. In the MesPyBTM-PhPyBTM-Mes, the mesityl group did not worked as an electron donor unlike the previously reported monoradical MesPyBTM. However, adding two n-hexyl groups on the bridging p-phenylene did greatly improve it, and the PLQY of the PyBTM-(Hex2Ph)PyBTM was 7 % in dichloromethane and acetone, and 12 % in poly(methyl methacrylate) (PMMA) film. Twisting p-phenylene linker by hexyl groups hindered the π-conjugation and suppressed the non-radiative decay of the excited state.
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Affiliation(s)
- Yohei Hattori
- Materials Chemistry Course, Faculty of Advanced Science and Technology, Ryukoku University Seta, Otsu, Shiga, 520-2194, Japan
| | - Kohei Yamamoto
- Materials Chemistry Course, Faculty of Advanced Science and Technology, Ryukoku University Seta, Otsu, Shiga, 520-2194, Japan
| | - Ryota Kitajima
- Materials Chemistry Course, Faculty of Advanced Science and Technology, Ryukoku University Seta, Otsu, Shiga, 520-2194, Japan
| | - Kingo Uchida
- Materials Chemistry Course, Faculty of Advanced Science and Technology, Ryukoku University Seta, Otsu, Shiga, 520-2194, Japan
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22
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Fabri B, Funaioli T, Frédéric L, Elsner C, Bordignon E, Zinna F, Di Bari L, Pescitelli G, Lacour J. Triple para-Functionalized Cations and Neutral Radicals of Enantiopure Diaza[4]helicenes. J Am Chem Soc 2024; 146:8308-8319. [PMID: 38483324 DOI: 10.1021/jacs.3c13487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Modulation of absorbance and emission is key for the design of chiral chromophores. Accessing a series of compounds absorbing and emitting (circularly polarized) light over a wide spectral window and often toward near-infrared is of practical value in (chir)optical applications. Herein, by late-stage functionalization on derivatives bridging triaryl methyl and helicene domains, we have achieved the regioselective triple introduction of para electron-donating or electron-withdrawing substituents. Extended tuning of electronic (e.g., E1/2red -1.50 V → -0.68 V) and optical (e.g., emission covering from 550 to 850 nm) properties is achieved for the cations and neutral radicals; the latter compounds being easily prepared by mono electron reductions under electrochemical or chemical conditions. While luminescence quantum yields can be increased up to 70% in the cationic series, strong Cotton effects are obtained for certain radicals at low energies (λabs ∼ 700-900 nm) with gabs values above 10-3. The open-shell electronic nature of the radicals was further characterized by electron paramagnetic resonance revealing an important spin density delocalization that contributes to their persistence.
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Affiliation(s)
- Bibiana Fabri
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, Geneva 4 1211, Switzerland
| | - Tiziana Funaioli
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via G. Moruzzi 13, Pisa 56124, Italy
| | - Lucas Frédéric
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, Geneva 4 1211, Switzerland
| | - Christina Elsner
- Department of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, Geneva 4 1211, Switzerland
| | - Enrica Bordignon
- Department of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, Geneva 4 1211, Switzerland
| | - Francesco Zinna
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via G. Moruzzi 13, Pisa 56124, Italy
| | - Lorenzo Di Bari
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via G. Moruzzi 13, Pisa 56124, Italy
| | - Gennaro Pescitelli
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via G. Moruzzi 13, Pisa 56124, Italy
| | - Jérôme Lacour
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, Geneva 4 1211, Switzerland
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23
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Zhang L, Li H, Zhu Y, Zhang S. A quantum-chemical insight into SOMO-HOMO conversion in phosphorus-boron cation radicals. Phys Chem Chem Phys 2024; 26:8273-8286. [PMID: 38385562 DOI: 10.1039/d4cp00098f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Organic radicals exhibiting SOMO-HOMO conversion (SHC) electronic configurations have recently garnered increasing attention due to their exceptional stability and photophysical properties. In this study, we investigate two series of phosphorus-boron cation radicals based on 1,3,5-trimethylphenyl units substituted with P and B atoms, varying numbers of P-B moieties, and π-conjugation linkers. We perform quantum-chemical calculations to systematically assess the influence of chemical substituents on the SHC electronic structural features. Our computational results demonstrate that the SHC electronic configurations of the studied complexes are primarily determined by the number of P-B moieties, specifically, phosphorus-boron cation radicals with two P-B moieties as terminal groups in π-conjugation linkers, which efficiently arrange electrons to increase HOMO energies compared to corresponding radicals with only one P-B unit. Furthermore, spin density distributions change as the size of π-conjugation linkers increases. Natural bond orbital (NBO) and atoms-in-molecules (AIM) analyses reveal strong intramolecular charge transfer between P and B atoms along with other stabilized donor-acceptor interactions and significant covalent bonds between P and B atoms. Moreover, synergistic effects resulting from 1,3,5-trimethylphenyl substitutions and enlarged π-conjugation linkers containing P-B units confer excellent photophysical properties upon these studied radicals, making them potential stable radicals in optoelectronic applications.
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Affiliation(s)
- Li Zhang
- School of Electronic Engineering, Guangxi University of Science and Technology, Liuzhou 545000, Guangxi, China.
| | - Hongbo Li
- School of Electronic Engineering, Guangxi University of Science and Technology, Liuzhou 545000, Guangxi, China.
| | - Yanbin Zhu
- School of Electronic Engineering, Guangxi University of Science and Technology, Liuzhou 545000, Guangxi, China.
| | - Shoufeng Zhang
- School of Electronic Engineering, Guangxi University of Science and Technology, Liuzhou 545000, Guangxi, China.
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24
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Ju CW, Shen Y, French EJ, Yi J, Bi H, Tian A, Lin Z. Accurate Electronic and Optical Properties of Organic Doublet Radicals Using Machine Learned Range-Separated Functionals. J Phys Chem A 2024. [PMID: 38382058 DOI: 10.1021/acs.jpca.3c07437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Luminescent organic semiconducting doublet-spin radicals are unique and emergent optical materials because their fluorescent quantum yields (Φfl) are not compromised by the spin-flipping intersystem crossing (ISC) into a dark high-spin state. The multiconfigurational nature of these radicals challenges their electronic structure calculations in the framework of single-reference density functional theory (DFT) and introduces room for method improvement. In the present study, we extended our earlier development of ML-ωPBE [J. Phys. Chem. Lett., 2021, 12, 9516-9524], a range-separated hybrid (RSH) exchange-correlation (XC) functional constructed using the stacked ensemble machine learning (SEML) algorithm, from closed-shell organic semiconducting molecules to doublet-spin organic semiconducting radicals. We assessed its performance for a new test set of 64 doublet-spin radicals from five categories while placing all previously compiled 3926 closed-shell molecules in the new training set. Interestingly, ML-ωPBE agrees with the nonempirical OT-ωPBE functional regarding the prediction of the molecule-dependent range-separation parameter (ω), with a small mean absolute error (MAE) of 0.0197 a0-1, but saves the computational cost by 2.46 orders of magnitude. This result demonstrates an outstanding domain adaptation capacity of ML-ωPBE for diverse organic semiconducting species. To further assess the predictive power of ML-ωPBE in experimental observables, we also applied it to evaluate absorption and fluorescence energies (Eabs and Efl) using linear-response time-dependent DFT (TDDFT), and we compared its behavior with nine popular XC functionals. For most radicals, ML-ωPBE reproduces experimental measurements of Eabs and Efl with small MAEs of 0.299 and 0.254 eV, only marginally different from those of OT-ωPBE. Our work illustrates a successful extension of the SEML framework from closed-shell molecules to doublet-spin radicals and will open the venue for calculating optical properties for organic semiconductors using single-reference TDDFT.
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Affiliation(s)
- Cheng-Wei Ju
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Yili Shen
- Manning College of Information and Computer Sciences, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Ethan J French
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Jun Yi
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Chemistry, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Hongshan Bi
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Aaron Tian
- Manning College of Information and Computer Sciences, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Zhou Lin
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
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25
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Mizuno A, Matsuoka R, Mibu T, Kusamoto T. Luminescent Radicals. Chem Rev 2024; 124:1034-1121. [PMID: 38230673 DOI: 10.1021/acs.chemrev.3c00613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Organic radicals are attracting increasing interest as a new class of molecular emitters. They demonstrate electronic excitation and relaxation dynamics based on their doublet or higher multiplet spin states, which are different from those based on singlet-triplet manifolds of conventional closed-shell molecules. Recent studies have disclosed luminescence properties and excited state dynamics unique to radicals, such as highly efficient electron-photon conversion in OLEDs, NIR emission, magnetoluminescence, an absence of heavy atom effect, and spin-dependent and spin-selective dynamics. These are difficult or sometimes impossible to achieve with closed-shell luminophores. This review focuses on luminescent organic radicals as an emerging photofunctional molecular system, and introduces the material developments, fundamental properties including luminescence, and photofunctions. Materials covered in this review range from monoradicals, radical oligomers, and radical polymers to metal complexes with radical ligands demonstrating radical-involved emission. In addition to stable radicals, transiently formed radicals generated in situ by external stimuli are introduced. This review shows that luminescent organic radicals have great potential to expand the chemical and spin spaces of luminescent molecular materials and thus broaden their applicability to photofunctional systems.
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Affiliation(s)
- Asato Mizuno
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Ryota Matsuoka
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, HayamaKanagawa 240-0193, Japan
| | - Takuto Mibu
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Tetsuro Kusamoto
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, HayamaKanagawa 240-0193, Japan
- JST-PRESTO, 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Japan
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
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26
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Valente G, Ferreira P, Hernández-Rodríguez MA, Brites CDS, Amaral JS, Zelenovskii P, Paz FAA, Guieu S, Rocha J, Souto M. Exploring the Luminescence, Redox, and Magnetic Properties in a Multivariate Metal-Organic Radical Framework. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:1333-1341. [PMID: 38370275 PMCID: PMC10870702 DOI: 10.1021/acs.chemmater.3c02460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/20/2024]
Abstract
Persistent neutral organic radicals are excellent building blocks for the design of functional molecular materials due to their unique electronic, magnetic, and optical properties. Among them, triphenylmethyl radical derivatives have attracted a lot of interest as luminescent doublet emitters. Although neutral organic radicals have been underexplored as linkers for building metal-organic frameworks (MOFs), they hold great potential as organic elements that could introduce additional electronic properties within these frameworks. Herein, we report the synthesis and characterization of a novel multicomponent metal-organic radical framework (PTMTCR@NR-Zn MORF), which is constructed from the combination of luminescent perchlorotriphenylmethyl tricarboxylic acid radical (PTMTCR) and nonemissive nonradical (PTMTCNR) organic linkers and Zn(II) ions. The PTMTCR@NR-Zn MORF structure is layered with microporous one-dimensional channels embedded within these layers. Kelvin probe force microscopy further confirmed the presence of both organic nonradical and radical linkers in the framework. The luminescence properties of the PTMTCR ligand (first studied in solution and in the solid state) were maintained in the radical-containing PTMTCR@NR-Zn MORF at room temperature as fluorescence solid-state quenching is suppressed thanks to the isolation of the luminescent radical linkers. In addition, magnetic and electrochemical properties were introduced to the framework due to the incorporation of the paramagnetic organic radical ligands. This work paves the way for the design of stimuli-responsive hybrid materials with tunable luminescence, electrochemical, and magnetic properties by the proper combination of closed- and open-shell organic linkers within the same framework.
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Affiliation(s)
- Gonçalo Valente
- Department
of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
| | - Pedro Ferreira
- Department
of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
| | | | - Carlos D. S. Brites
- Department
of Physics, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
| | - João S. Amaral
- Department
of Physics, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
| | - Pavel Zelenovskii
- Department
of Physics, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
| | - Filipe A. Almeida Paz
- Department
of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
| | - Samuel Guieu
- Department
of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
- Department
of Chemistry, LAQV-REQUIMTE, University
of Aveiro, Aveiro 3810-393, Portugal
| | - João Rocha
- Department
of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
| | - Manuel Souto
- Department
of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro 3810-393, Portugal
- CIQUS,
Centro Singular de Investigación en Química Bioloxica
e Materiais Moleculares, Departamento de Química-Física, Universidade de Santiago de Compostela, 15782 Santiago
de Compostela, Spain
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27
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Feng Z, Zhou J, He X, Wang B, Xie G, Qiao X, Liu L, Xie Z, Ma Y. Extremely Stable Perylene Bisimide-Bridged Regioisomeric Diradicals and Their Redox Properties. Chemistry 2024; 30:e202302943. [PMID: 37803935 DOI: 10.1002/chem.202302943] [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: 09/11/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/08/2023]
Abstract
Excellent stability is an essential premise for organic diradicals to be used in organic electronic and spintronic devices. We have attached two tris(2,4,6-trichlorophenyl)methyl (TTM) radical building blocks to the two sides of perylene bisimide (PBI) bridges and obtained two regioisomeric diradicals (1,6-TTM-PBI and 1,7-TTM-PBI). Both of the isomers show super stability rather than the monomeric TTM under ambient conditions, due to the increased conjugation and the electron-withdrawing effects of the PBI bridges. The diradicals show distinct and reversible multistep redox processes, and a spectro-electrochemistry investigation revealed the generation of organic mixed-valence (MV) species during reduction processes. The two diradicals have singlet ground states, very small singlet-triplet energy gaps (ΔES-T ) and a pure open-shell character (with diradical character y0 =0.966 for 1,6-TTM-PBI and 0.967 for 1,7-TTM-PBI). This work opens a window to developing very stable diradicals and offers the opportunity of their further application in optical, electronic and magnetic devices.
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Affiliation(s)
- Zhibin Feng
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Jiadong Zhou
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Xiandong He
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Bohan Wang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Guojing Xie
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Xianfeng Qiao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Linlin Liu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Zengqi Xie
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Yuguang Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
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28
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Xu Y, Teng C, Dang H, Yin D, Yan L. Highly bright stable organic radicals encapsulated by amphiphilic polypeptide for efficient near-infrared phototheranostics. Talanta 2024; 266:124948. [PMID: 37459788 DOI: 10.1016/j.talanta.2023.124948] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/07/2023] [Accepted: 07/12/2023] [Indexed: 09/20/2023]
Abstract
Stable organic radical molecules have received extensive attention due to their unique electronic structure and photophysical properties, and the highly fluorescent quantum efficiency has great appeal to bioimaging. However, still scarce reports on the application of them on the therapy of tumors, especially theranostics. Here, 3,6-dibromocarbazole modified tris (2,4,6-trichlorophenyl) methane radical (TB) has been synthesized with high NIR fluorescence quantum efficiency, and free radical nanoparticles (NPs) have been prepared using the precursor of the radical doping strategy. The free radical molecule TB and its precursor molecule HTB were mixed in proportion and encapsulated with an amphiphilic polypeptide (PEG-PAsp) to obtain the NPs. The 4% NPs can achieve a high fluorescence quantum efficiency (18.68%) in the NIR region. In addition, the NPs also have a good ability to produce reactive oxygen species (ROS) under either normoxia or hypoxia conditions, which makes it possible for photodynamic therapy (PDT). Interestingly, the NPs also show preferable photothermal ability (PCE = 42.39%) for photothermal therapy (PTT). Both in vitro and in vivo studies reveal that the as-prepared radical NPS show a NIR fluorescence imaging-guided synergistic PTT and type I/II PDT to tumors. It provides new strategies and new clues for the application of free radical molecules in the theranostics of tumors.
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Affiliation(s)
- Yixuan Xu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China. Hefei, Jinzai Road 96, 230026, Anhui, PR China; Key Laboratory of Precision and Intelligent Chemistry, And Department of Chemical Physics, University of Science and Technology of China. Hefei, Jinzai Road 96, 230026, Anhui, PR China
| | - Changchang Teng
- Key Laboratory of Precision and Intelligent Chemistry, And Department of Chemical Physics, University of Science and Technology of China. Hefei, Jinzai Road 96, 230026, Anhui, PR China
| | - Huiping Dang
- Key Laboratory of Precision and Intelligent Chemistry, And Department of Chemical Physics, University of Science and Technology of China. Hefei, Jinzai Road 96, 230026, Anhui, PR China
| | - Dalong Yin
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China. Hefei, Jinzai Road 96, 230026, Anhui, PR China
| | - Lifeng Yan
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China. Hefei, Jinzai Road 96, 230026, Anhui, PR China; Key Laboratory of Precision and Intelligent Chemistry, And Department of Chemical Physics, University of Science and Technology of China. Hefei, Jinzai Road 96, 230026, Anhui, PR China.
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29
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Gao Y, Liu Y, Li X, Wang H, Yang Y, Luo Y, Wan Y, Lee CS, Li S, Zhang XH. A Stable Open-Shell Conjugated Diradical Polymer with Ultra-High Photothermal Conversion Efficiency for NIR-II Photo-Immunotherapy of Metastatic Tumor. NANO-MICRO LETTERS 2023; 16:21. [PMID: 37982963 PMCID: PMC10660627 DOI: 10.1007/s40820-023-01219-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/28/2023] [Indexed: 11/21/2023]
Abstract
Massive efforts have been concentrated on the advance of eminent near-infrared (NIR) photothermal materials (PTMs) in the NIR-II window (1000-1700 nm), especially organic PTMs because of their intrinsic biological safety compared with inorganic PTMs. However, so far, only a few NIR-II-responsive organic PTMs was explored, and their photothermal conversion efficiencies (PCEs) still remain relatively low. Herein, donor-acceptor conjugated diradical polymers with open-shell characteristics are explored for synergistically photothermal immunotherapy of metastatic tumors in the NIR-II window. By employing side-chain regulation, the conjugated diradical polymer TTB-2 with obvious NIR-II absorption was developed, and its nanoparticles realize a record-breaking PCE of 87.7% upon NIR-II light illustration. In vitro and in vivo experiments demonstrate that TTB-2 nanoparticles show good tumor photoablation with navigation of photoacoustic imaging in the NIR-II window, without any side-effect. Moreover, by combining with PD-1 antibody, the pulmonary metastasis of breast cancer is high-effectively prevented by the efficient photo-immunity effect. Thus, this study explores superior PTMs for cancer metastasis theranostics in the NIR-II window, offering a new horizon in developing radical-characteristic NIR-II photothermal materials.
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Affiliation(s)
- Yijian Gao
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, People's Republic of China
| | - Ying Liu
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, People's Republic of China
| | - Xiliang Li
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, People's Republic of China
| | - Hui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, 215123, People's Republic of China
| | - Yuliang Yang
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, People's Republic of China
| | - Yu Luo
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, People's Republic of China
| | - Yingpeng Wan
- Center of Super-Diamond and Advanced Films (COSDAF) & Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People's Republic of China
| | - Chun-Sing Lee
- Center of Super-Diamond and Advanced Films (COSDAF) & Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, People's Republic of China.
| | - Shengliang Li
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, People's Republic of China.
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, 215123, People's Republic of China.
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30
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Ohisa S, Honda S. Luminescence enhancement by symmetry-breaking in the excited state in radical organic light-emitting diodes. Commun Chem 2023; 6:238. [PMID: 37919478 PMCID: PMC10622504 DOI: 10.1038/s42004-023-01039-5] [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: 09/08/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
Organic π-conjugated radicals have recently joined the ranks of high-efficiency light-emitting materials, however, their light-emission mechanism is still a matter of debate. Here, the authors highlight a recently proposed luminescent enhancement mechanism and record-breaking efficiency of a radical organic light-emitting diode.
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Affiliation(s)
- Satoru Ohisa
- Science & Technology Research Laboratories, Japan Broadcasting Corporation (NHK), 1-10-11 Kinuta, Setagaya-ku, Tokyo, 157-8510, Japan.
| | - Satoshi Honda
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
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31
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Luo X, Zhang Z, Wang J, Wang X, Zhang Y, Chen J, Ge G, Yang W, Qian X, Tian Y, Yang Y. Acyl-caged rhodamines: photo-controlled and self-calibrated generation of acetyl radicals for neural function recovery in early AD mice. Chem Sci 2023; 14:11689-11698. [PMID: 37920344 PMCID: PMC10619617 DOI: 10.1039/d3sc03035k] [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: 06/14/2023] [Accepted: 09/13/2023] [Indexed: 11/04/2023] Open
Abstract
The biological function of radicals is a broad continuum from signaling to killing. Yet, biomedical exploitation of radicals is largely restricted to the theme of healing-by-killing. To explore their potential in healing-by-signaling, robust radical generation methods are warranted. Acyl radicals are endogenous, exhibit facile chemistry and elicit matrix-dependent biological outcomes. Their implications in health and disease remain untapped, primarily due to the lack of a robust generation method with spatiotemporal specificity. Fusing the Norrish chemistry into the xanthene scaffold, we developed a novel general and modular molecular design strategy for photo-triggered generation of acyl radicals, i.e., acyl-caged rhodamine (ACR). A notable feature of ACR is the simultaneous release of a fluorescent probe for cell redox homeostasis allowing real-time monitoring of the biological outcome of acyl radicals. With a donor of the endogenous acetyl radical (ACR575a), we showcased its capability in precise and continuous modulation of the cell redox homeostasis from signaling to stress, and induction of a local oxidative burst to promote differentiation of neural stem cells (NSCs). Upon intracerebral-injection of ACR575a and subsequent fiber-optical activation, early AD mice exhibited enhanced differentiation of NSCs toward neurons, reduced formation of Aβ plaques, and significantly improved cognitive abilities, including learning and memory.
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Affiliation(s)
- Xiao Luo
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University Dongchuan Road 500 Shanghai 200241 China
| | - Zhonghui Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University Dongchuan Road 500 Shanghai 200241 China
| | - Jie Wang
- Department of Molecular and Cellular Biochemistry, School of Medicine, Shanghai Jiaotong University Chongqing South Road 280 Shanghai 200025 China
| | - Xueli Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University Dongchuan Road 500 Shanghai 200241 China
| | - Yani Zhang
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine Cailun Road 1200 Shanghai 201203 China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University Dongchuan Road 500 Shanghai 200241 China
| | - Guangbo Ge
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine Cailun Road 1200 Shanghai 201203 China
| | - Wen Yang
- Department of Molecular and Cellular Biochemistry, School of Medicine, Shanghai Jiaotong University Chongqing South Road 280 Shanghai 200025 China
| | - Xuhong Qian
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University Dongchuan Road 500 Shanghai 200241 China
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology Meilong Road 130 Shanghai 200237 China
| | - Yang Tian
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University Dongchuan Road 500 Shanghai 200241 China
| | - Youjun Yang
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology Meilong Road 130 Shanghai 200237 China
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32
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Cho HH, Gorgon S, Hung HC, Huang JY, Wu YR, Li F, Greenham NC, Evans EW, Friend RH. Efficient and Bright Organic Radical Light-Emitting Diodes with Low Efficiency Roll-Off. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303666. [PMID: 37684741 DOI: 10.1002/adma.202303666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 08/08/2023] [Indexed: 09/10/2023]
Abstract
Organic radicals have been of interest due to their potential to replace nonradical-based organic emitters, especially for deep-red/near-infrared (NIR) electroluminescence (EL), based on the spin-allowed doublet fluorescence. However, the performance of the radical-based EL devices is limited by low carrier mobility which causes a large efficiency roll-off at high current densities. Here, highly efficient and bright doublet EL devices are reported by combining a thermally activated delayed fluorescence (TADF) host that supports both electron and hole transport and a tris(2,4,6-trichlorophenyl)methyl-based radical emitter. Steady-state and transient photophysical studies reveal the optical signatures of doublet luminescence mechanisms arising from both host and guest photoexcitation. The host system presented here allows balanced hole and electron currents, and a high maximum external quantum efficiency (EQE) of 17.4% at 707 nm peak emission with substantially improved efficiency roll-off is reported: over 70% of the maximum EQE (12.2%) is recorded at 10 mA cm-2 , and even at 100 mA cm-2 , nearly 50% of the maximum EQE (8.4%) is maintained. This is an important step in the practical application of organic radicals to NIR light-emitting devices.
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Affiliation(s)
- Hwan-Hee Cho
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Sebastian Gorgon
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Hsiao-Chun Hung
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, 10617, Taipei, Taiwan
| | - Jun-Yu Huang
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, 10617, Taipei, Taiwan
| | - Yuh-Renn Wu
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, 10617, Taipei, Taiwan
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Qianjin Avenue 2699, Changchun, 130012, P. R. China
| | - Neil C Greenham
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Emrys W Evans
- Department of Chemistry, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Richard H Friend
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
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33
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Shu C, Yang Z, Rajca A. From Stable Radicals to Thermally Robust High-Spin Diradicals and Triradicals. Chem Rev 2023; 123:11954-12003. [PMID: 37831948 DOI: 10.1021/acs.chemrev.3c00406] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
Stable radicals and thermally robust high-spin di- and triradicals have emerged as important organic materials due to their promising applications in diverse fields. New fundamental properties, such as SOMO/HOMO inversion of orbital energies, are explored for the design of new stable radicals, including highly luminescent ones with good photostability. A relation with the singlet-triplet energy gap in the corresponding diradicals is proposed. Thermally robust high-spin di- and triradicals, with energy gaps that are comparable to or greater than a thermal energy at room temperature, are more challenging to synthesize but more rewarding. We summarize a number of high-spin di- and triradicals, based on nitronyl nitroxides that provide a relation between the experimental pairwise exchange coupling constant J/k in the high-spin species vs experimental hyperfine coupling constants in the corresponding monoradicals. This relation allows us to identify outliers, which may correspond to radicals where J/k is not measured with sufficient accuracy. Double helical high-spin diradicals, in which spin density is delocalized over the chiral π-system, have been barely explored, with the sole example of such high-spin diradical possessing alternant π-system with Kekulé resonance form. Finally, we discuss a high-spin diradical with electrical conductivity and derivatives of triangulene diradicals.
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Affiliation(s)
- Chan Shu
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Zhimin Yang
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
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34
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Duan J, Shi Y, Zhao F, Li C, Duan Z, Zhang N, Chen P. Chiral Luminescent Aza[7]helicenes Functionalized with a Triarylborane Acceptor and Near-Infrared-Emissive Doublet-State Radicals. Inorg Chem 2023; 62:15829-15833. [PMID: 37713177 DOI: 10.1021/acs.inorgchem.3c02470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
This paper presents new chiral luminescent molecules (N7-BMes2 and N7-TTM) using configurationally stable aza[7]helicene (1) as a universal heteroatom-doped chiral scaffold. The respective reactions of electron-donating 1 with a triarylborane acceptor via palladium-catalyzed Buchwald-Hartwig C-N coupling and with the open-shell doublet-state TTM radical via nucleophilic aromatic substitution (SN2Ar) resulted not only in tunable emissions from blue to the NIR domain but also in significantly enhanced emission quantum efficiency up to Φ = 50%.
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Affiliation(s)
- Jiaxian Duan
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China
| | - Yafei Shi
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China
| | - Fei Zhao
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China
| | - Chenglong Li
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China
| | - Zhihua Duan
- Baoshan Animal Disease Prevention and Control Center, Baoshan 678000, Yunnan, China
| | - Niu Zhang
- Analysis and Testing Centre, Beijing Institute of Technology, Beijing 102488, China
| | - Pangkuan Chen
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China
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35
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Fei LR, Wang J, Bai FQ, Wang SP, Hu B, Kong CP, Zhang HX. Investigating the influence of substituent groups in TTM based radicals for the excitation process: a theoretical study. Phys Chem Chem Phys 2023; 25:25871-25879. [PMID: 37725156 DOI: 10.1039/d3cp01248d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Tri-(2,4,6-trichlorophenyl)methyl (TTM) based radicals can be promising in providing relatively high fluorescence quantum efficiency. In this study, we have evaluated the photoluminescence properties of a series of TTM-based radicals by means of DFT and TD-DFT methods. The optimized structures of the ground states (D0) and the first excited states (D1) of all the radicals are calculated and the computed emission bands are comparable with previous experimental results. knr is determined from transition dipole moments (μ12) and the energy gaps between D0 and D1 (ΔE), both of which can be regulated by the conjugated structures from the substituent groups. knr was derived from the mode-averaging method and is consistent with the experimental results. Factors influencing kr and knr, including the potential energy differences (ΔG0), the vibrational reorganization energies (λ) and the electron coupling term (Hab), are discussed. By comparing kr and knr in solvents with different polarities (cyclohexane, toluene, and chloroform), TTM based radicals in cyclohexane exhibit the most promising fluorescence efficiencies. Besides, two substituted radicals, namely 2Br-TTM-3PCz and 2F-TTM-3PCz, have been fabricated. The results show that fluorine atoms are able to increase ΔG0 and a considerably small knr has been predicted. We expect that our calculation can benefit the design of light-emitting molecules in further experiments.
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Affiliation(s)
- Lu-Ran Fei
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical, Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China.
| | - Jian Wang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical, Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China.
| | - Fu-Quan Bai
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical, Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China.
| | - Shi-Ping Wang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical, Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China.
| | - Bin Hu
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical, Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China.
| | - Chui-Peng Kong
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical, Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China.
| | - Hong-Xing Zhang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical, Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China.
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36
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Punzi A, Dai Y, Dibenedetto CN, Mesto E, Schingaro E, Ullrich T, Striccoli M, Guldi DM, Negri F, Farinola GM, Blasi D. Dark State of the Thiele Hydrocarbon: Efficient Solvatochromic Emission from a Nonpolar Centrosymmetric Singlet Diradicaloid. J Am Chem Soc 2023; 145:20229-20241. [PMID: 37671971 DOI: 10.1021/jacs.3c05251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
In this work, a comprehensive investigation of the photoinduced processes and mechanisms linked to the luminescence of a novel nonperchlorinated Thiele hydrocarbon (TTH) is presented. Despite the comparable diradical character of TTH (y0 = 0.32-0.44) and the unsubstituted Thiele hydrocarbon (TH) (y0 = 0.30), the polyhalogenated species is inert and photostable, showing an intense deep-red/near-infrared (NIR) fluorescence (photoluminescence quantum yield (PLQY) = 0.84 in toluene) even at room temperature and in the solid state (PLQY = 0.19). TTH displays a large Stokes shift (307 nm in benzonitrile) and solvatochromic behavior, which is unusual for a centrosymmetric, nonpolar, and low-conjugated species. These outstanding emission features are interpreted through quantum-chemical calculations, indicating that its fluorescence arises from the low-lying dark doubly excited zwitterionic state, typically found at low excitation energies in diradicaloids, acquiring dipole moment and intensity by state mixing via twisting around the strongly elongated exocyclic CC bonds of the excited p-quinodimethane (pQDM) core, with a mechanism similar to sudden polarization occurring in olefins. Such a mechanism is derived from ns and fs transient absorption measurements.
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Affiliation(s)
- Angela Punzi
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Yasi Dai
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna and INSTM UdR Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Carlo N Dibenedetto
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
- CNR-Istituto per i Processi Chimico Fisici (CNR-IPCF), SS Bari, Via E. Orabona 4, 70125 Bari, Italy
| | - Ernesto Mesto
- Dipartimento di Scienze della Terra e Geoambientali, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Emanuela Schingaro
- Dipartimento di Scienze della Terra e Geoambientali, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Tobias Ullrich
- Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, 91058 Erlangen, Germany
| | - Marinella Striccoli
- CNR-Istituto per i Processi Chimico Fisici (CNR-IPCF), SS Bari, Via E. Orabona 4, 70125 Bari, Italy
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, 91058 Erlangen, Germany
| | - Fabrizia Negri
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna and INSTM UdR Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Gianluca M Farinola
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Davide Blasi
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
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37
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Ajaykamal T, Palaniandavar M. Mononuclear nickel(ii)-flavonolate complexes of tetradentate tripodal 4N ligands as structural and functional models for quercetin 2,4-dioxygenase: structures, spectra, redox and dioxygenase activity. RSC Adv 2023; 13:24674-24690. [PMID: 37601601 PMCID: PMC10436029 DOI: 10.1039/d3ra04834a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 08/01/2023] [Indexed: 08/22/2023] Open
Abstract
Three new nickel(ii)-flavonolate complexes of the type [Ni(L)(fla)](ClO4) 1-3, where L is the tripodal 4N ligand tris(pyrid-2-ylmethyl)amine (tpa, L1) or (pyrid-2-ylmethyl)bis(6-methylpyrid-2-ylmethyl)amine (6-Me2-tpa, L2) or tris(N-Et-benzimidazol-2-ylmethyl)amine (Et-ntb, L3), have been isolated as functional models for Ni(ii)-containing quercetin 2,4-dioxygenase. Single crystal X-ray structures of 1 and 3 reveal that Ni(ii) is involved in π-back bonding with flavonolate (fla-), as evident from enhancement in C[double bond, length as m-dash]O bond length upon coordination [H(fla), 1.232(3); 1, 1.245(7); 3, 1.262(8) Å]. More asymmetric chelation of fla- in 3 than in 1 [Δd = (Ni-Ocarbonyl - Ni-Oenolate): 1, 0.126; 3, 0.182 Å] corresponds to lower π-delocalization in 3 with electron-releasing N-Et substituent. The optimized structures of 1-3 and their geometrical isomers have been computed by DFT methods. The HOMO and LUMO, both localized on Ni(ii)-bound fla-, are highly conjugated bonding π- and antibonding π*-orbitals respectively. They are located higher in energy than the Ni(ii)-based MOs (HOMO-1, dx2-y2; HOMO-2/6, dz2), revealing that the Ni(ii)-bound fla- rather than Ni(ii) would undergo oxidation upon exposure to dioxygen. The results of computational studies, in combination with spectral and electrochemical studies, support the involvement of redox-inactive Ni(ii) in π-back bonding with fla-, tuning the π-delocalization in fla- and hence its activation. Upon exposure to dioxygen, all the flavonolate adducts in DMF solution decompose to produce CO and depside, which then is hydrolyzed to give the corresponding acids at 70 °C. The highest rate of dioxygenase reactivity of 3 (kO2: 3 (29.10 ± 0.16) > 1 (16.67 ± 0.70) > 2 (1.81 ± 0.04 × 10-1 M-1 s-1)), determined by monitoring the disappearance of the LMCT band in the range 440-450 nm, is ascribed to the electron-releasing N-Et substituent on bzim ring, which decreases the π-delocalization in fla- and enhances its activation.
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Affiliation(s)
- Tamilarasan Ajaykamal
- Department of Chemistry, Bharathidasan University Tiruchirapalli 620 024 Tamil Nadu India +91-431-2407043 +91-431-2407125
| | - Mallayan Palaniandavar
- Department of Chemistry, Bharathidasan University Tiruchirapalli 620 024 Tamil Nadu India +91-431-2407043 +91-431-2407125
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Murto P, Chowdhury R, Gorgon S, Guo E, Zeng W, Li B, Sun Y, Francis H, Friend RH, Bronstein H. Mesitylated trityl radicals, a platform for doublet emission: symmetry breaking, charge-transfer states and conjugated polymers. Nat Commun 2023; 14:4147. [PMID: 37438369 DOI: 10.1038/s41467-023-39834-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/29/2023] [Indexed: 07/14/2023] Open
Abstract
Neutral π-radicals have potential for use as light emitters in optoelectronic devices due to the absence of energetically low-lying non-emissive states. Here, we report a defect-free synthetic methodology via mesityl substitution at the para-positions of tris(2,4,6-trichlorophenyl)methyl radical. These materials reveal a number of novel optoelectronic properties. Firstly, mesityl substituted radicals show strongly enhanced photoluminescence arising from symmetry breaking in the excited state. Secondly, photoexcitation of thin films of 8 wt% radical in 4,4'-bis(carbazol-9-yl)-1,1'-biphenyl host matrix produces long lived (in the order of microseconds) intermolecular charge transfer states, following hole transfer to the host, that can show unexpectedly efficient red-shifted emission. Thirdly, covalent attachment of carbazole into the mesitylated radical gives very high photoluminescence yield of 93% in 4,4'-bis(carbazol-9-yl)-1,1'-biphenyl films and light-emitting diodes with maximum external quantum efficiency of 28% at a wavelength of 689 nm. Fourthly, a main-chain copolymer of the mesitylated radical and 9,9-dioctyl-9H-fluorene shows red-shifted emission beyond 800 nm.
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Affiliation(s)
- Petri Murto
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | | | - Sebastian Gorgon
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Erjuan Guo
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
- State Key Laboratory of Materials Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, China
| | - Weixuan Zeng
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Biwen Li
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Yuqi Sun
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Haydn Francis
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Richard H Friend
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK.
| | - Hugo Bronstein
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK.
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK.
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Ma Z, Zhang L, Cui Z, Ai X. Improving the Luminescence and Stability of Carbon-Centered Radicals by Kinetic Isotope Effect. Molecules 2023; 28:4805. [PMID: 37375360 DOI: 10.3390/molecules28124805] [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: 05/25/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
The kinetic isotope effect (KIE) is beneficial to improve the performance of luminescent molecules and relevant light-emitting diodes. In this work, the influences of deuteration on the photophysical property and stability of luminescent radicals are investigated for the first time. Four deuterated radicals based on biphenylmethyl, triphenylmethyl, and deuterated carbazole were synthesized and sufficiently characterized. The deuterated radicals exhibited excellent redox stability, as well as improved thermal and photostability. The appropriate deuteration of relevant C-H bonds would effectively suppress the non-radiative process, resulting in the increase in photoluminescence quantum efficiency (PLQE). This research has demonstrated that the introduction of deuterium atoms could be an effective pathway to develop high-performance luminescent radicals.
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Affiliation(s)
- Zhichao Ma
- School of Materials Science and Engineering, Collaborative Innovation Center of Information Technology, Collaborative Innovation Center of Marine Science and Technology, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
| | - Lintao Zhang
- School of Materials Science and Engineering, Collaborative Innovation Center of Information Technology, Collaborative Innovation Center of Marine Science and Technology, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
| | - Zhiyuan Cui
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, No. 2699, Qianjin Avenue, Changchun 130012, China
| | - Xin Ai
- School of Materials Science and Engineering, Collaborative Innovation Center of Information Technology, Collaborative Innovation Center of Marine Science and Technology, Hainan University, No 58, Renmin Avenue, Haikou 570228, China
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40
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Xu J, Guo J, Li S, Yang Y, Lai W, Keoingthong P, Wang S, Zhang L, Dong Q, Zeng Z, Chen Z. Dual Charge Transfer Generated from Stable Mixed-Valence Radical Crystals for Boosting Solar-to-Thermal Conversion. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023:e2300980. [PMID: 37144542 PMCID: PMC10375089 DOI: 10.1002/advs.202300980] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/11/2023] [Indexed: 05/06/2023]
Abstract
Realizing dual charge transfer (CT) based on stable organic radicals in one system is a long-sought goal, however, remains challenging. In this work, a stable mixed-valence radical crystal is designed via a surfactant-assisted method, namely TTF-(TTF+• )2 -RC (where TTF = tetrathiafulvalene), containing dual CT interactions. The solubilization of surfactants enables successful co-crystallization of mixed-valence TTF molecules with different polarity in aqueous solutions. Short intermolecular distances between adjacent TTF moieties within TTF-(TTF+• )2 -RC facilitate both inter-valence CT (IVCT) between neutral TTF and TTF+• , and inter-radical CT (IRCT) between two TTF+• in radical π-dimer, which are confirmed by single-crystal X-ray diffraction, solid-state absorption, electron spin resonance measurements, and DFT calculations. Moreover, TTF-(TTF+• )2 -RC reveals an open-shell singlet diradical ground state with the antiferromagnetic coupling of 2J = -657 cm-1 and an unprecedented temperature-dependent magnetic property, manifesting the main monoradical characters of IVCT at 113-203 K while the spin-spin interactions in radical dimers of IRCT are predominant at 263-353 K. Notably, dual CT characters endow TTF-(TTF+• )2 -RC with strong light absorption over the full solar spectrum and outstanding stability. As a result, TTF-(TTF+• )2 -RC exhibits significantly enhanced photothermal property, an increase of 46.6 °C within 180 s upon one-sun illumination.
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Affiliation(s)
- Jieqiong Xu
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
| | - Jing Guo
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha, Hunan, 410082, China
| | - Shengkai Li
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
| | - Yanxia Yang
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
| | - Weiming Lai
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha, Hunan, 410082, China
| | - Phouphien Keoingthong
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
| | - Shen Wang
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
| | - Liang Zhang
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
| | - Qian Dong
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
| | - Zebing Zeng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha, Hunan, 410082, China
| | - Zhuo Chen
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, 410082, China
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41
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Gao S, Cui Z, Li F. Doublet-emissive materials for organic light-emitting diodes: exciton formation and emission processes. Chem Soc Rev 2023; 52:2875-2885. [PMID: 37052349 DOI: 10.1039/d2cs00772j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Doublet-emission is mainly discovered in stable radicals, lanthanide-metal complexes with an f1 electron configuration and transition-metal complexes with a low-spin d5 electron configuration, and has a distinct radiation mechanism from closed-shell luminescent molecules and thus technology opportunities. There exists an unpaired electron in the frontier molecular orbitals which enables efficient nanosecond-scale luminescence in these materials due to the spin-allowed transitions between doublet-spin states. In this review, we summarize recent advances in these materials and their application in organic light emitting diodes (OLEDs). The photoluminescence and electroluminescence mechanisms of different doublet-emissive molecular systems are discussed, in addition to the photophysical phenomena arising from doublet states. We also outline the current challenges faced by each molecular system, and the potential outlook on the future research trends in this field.
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Affiliation(s)
- Shengxiang Gao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
| | - Zhiyuan Cui
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
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42
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Yang Y, Qiu L, Shi X. Chalcogen Effect of Atom Substitution on the Properties of Tris(2,4,6-trichlorophenyl)methyl(TTM) Radical. Chem Res Chin Univ 2023. [DOI: 10.1007/s40242-023-3008-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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43
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Xu J, Li S, Yang Y, Chen Z. Stable Organic Radicals Participation in Charge Transfer: A New Strategy toward Molecular Functional Materials. Chemistry 2023; 29:e202203598. [PMID: 36527171 DOI: 10.1002/chem.202203598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/14/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Charge-transfer (CT) engineering with inter-/intramolecular CT interactions by simple compositions has emerged as a universal and efficient way to construct organic functional materials. Stable organic radicals with unique physicochemical properties that cannot be realized in closed-shell molecules, have been widely demonstrated to be ideal building blocks to construct versatile organic CT materials. This concept article provides a brief overview of the advances in the design, structure and property of stable organic radicals-based CT molecular functional materials, and the strategy for the generation of these materials is also highlighted. First, radicals are introduced as open-shell donors or acceptors, with a focus on their importance and uniqueness in improving electrical, magnetic and optical properties of CT functional materials. Additionally, CT interactions in stable radical dimers and trimers are further discussed systematically. Finally, the challenges are summarized and perspectives for future development of stable organic radicals-based CT functional materials are provided.
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Affiliation(s)
- Jieqiong Xu
- Molecular Science and Biomedicine Laboratory State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province, Hunan University Changsha, Hunan, 410082, P. R. China
| | - Shengkai Li
- Molecular Science and Biomedicine Laboratory State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province, Hunan University Changsha, Hunan, 410082, P. R. China
| | - Yanxia Yang
- Molecular Science and Biomedicine Laboratory State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province, Hunan University Changsha, Hunan, 410082, P. R. China
| | - Zhuo Chen
- Molecular Science and Biomedicine Laboratory State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan Province, Hunan University Changsha, Hunan, 410082, P. R. China
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44
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Effects of Electron Donating Ability of Substituents and Molecular Conjugation on the Electronic Structures of Organic Radicals. Chem Res Chin Univ 2023. [DOI: 10.1007/s40242-023-2364-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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45
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Chen L, Rudolf T, Blinder R, Suryadevara N, Dalmeida A, Welscher PJ, Lamla M, Arnold M, Herr U, Jelezko F, Ruben M, Kuehne AJC. Red-Fluorescing Paramagnetic Conjugated Polymer Nanoparticles─Triphenyl Methyl Radicals as Monomers in C–C Cross-Coupling Dispersion Polymerization. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Affiliation(s)
- Lisa Chen
- Institute of Organic and Macromolecular Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Tamara Rudolf
- Institute of Organic and Macromolecular Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Rémi Blinder
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Nithin Suryadevara
- Institute of Quantum Materials and Technologies, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Ashley Dalmeida
- Institute for Functional Nanosystems, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm, Germany
| | - Philipp J. Welscher
- Institute of Organic and Macromolecular Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Markus Lamla
- Institute of Organic and Macromolecular Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Mona Arnold
- Institute of Organic and Macromolecular Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Ulrich Herr
- Institute for Functional Nanosystems, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm, Germany
| | - Fedor Jelezko
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Mario Ruben
- Institute of Quantum Materials and Technologies, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Centre Européen de Sciences Quantiques (CESQ), Institut de Science et d’Ingénierie Supramoléculaires (ISIS), 8 allée Gaspard Monge, BP 70028, 67083 Strasbourg, France
| | - Alexander J. C. Kuehne
- Institute of Organic and Macromolecular Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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46
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Li X, Tan W, Bai X, Li F. Stable Near-infrared-emitting Radical Nanoparticles for Fluorescence Imaging. Chem Res Chin Univ 2023. [DOI: 10.1007/s40242-023-2365-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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47
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Wang P, Hu J, Xu Z, Pu Z, Sato S, Zhang X, Hu W, Sun Z. Synthesis and structure elucidation of triarylmethyl radicals with anthryl substitution. Chem Commun (Camb) 2023; 59:2015-2018. [PMID: 36723079 DOI: 10.1039/d2cc06083c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Two stable triarylmethyl radicals with one or two anthryl substitutions are synthesized in gram scale, and are isolated in the crystalline state. Detailed structural elucidation with X-ray crystallographic analysis and DFT calculations revealed that the twisted structure is more energetically favorable than the folded structure, and consequently, the spin density is mainly localized at the methyl carbon. The spin distribution leads to unique physical properties, making them promising open-shell organic materials.
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Affiliation(s)
- Peng Wang
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China. .,Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China.
| | - Jinlian Hu
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
| | - Zhaofangzhou Pu
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
| | - Sota Sato
- Department of Applied Chemistry, Integrated Molecular Structure Analysis Laboratory, Social Cooperation Program, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Xiaotao Zhang
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China.
| | - Wenping Hu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China. .,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China. .,Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China. .,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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48
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Abdurahman A, Wang J, Zhao Y, Li P, Shen L, Peng Q. A Highly Stable Organic Luminescent Diradical. Angew Chem Int Ed Engl 2023; 62:e202300772. [PMID: 36781392 DOI: 10.1002/anie.202300772] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/11/2023] [Accepted: 02/13/2023] [Indexed: 02/15/2023]
Abstract
It is very challenging to obtain stable room-temperature luminescent open-shell singlet diradicals. Herein we report the first stable Müller's hydrocarbon TTM-PhTTM with luminescent properties. Variable-temperature electron paramagnetic resonance spectroscopy measurements and theoretical calculations show that TTM-PhTTM has an open-shell singlet ground state with a diradical character of 90 %. Because of a small singlet-triplet energy gap, the open-shell singlet ground state can be thermally excited to a triplet state. TTM-PhTTM shows room-temperature deep-red emission in various solutions. Unusually high stability of TTM-PhTTM was also observed owing to effective steric hindrance and spin delocalization. Our results are beneficial to the rational design and discovery of more stable luminescent diradical materials.
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Affiliation(s)
- Alim Abdurahman
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Qianjin Avenue 2699, Changchun, 130012, P. R. China
| | - Jingmin Wang
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, China
| | - Yihan Zhao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Qianjin Avenue 2699, Changchun, 130012, P. R. China
| | - Ping Li
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Li Shen
- College of Chemical Engineering and Environmental Chemistry, Weifang University, Weifang, 261061, China
| | - Qiming Peng
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, China
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49
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Lu C, Cho E, Cui Z, Gao Y, Cao W, Brédas JL, Coropceanu V, Li F. Towards Efficient and Stable Donor-Acceptor Luminescent Radicals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208190. [PMID: 36417767 DOI: 10.1002/adma.202208190] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/01/2022] [Indexed: 06/16/2023]
Abstract
In contrast to closed-shell luminescent molecules, the electronic ground state and lowest excited state in organic luminescent radicals are both spin doublet, which results in spin-allowed radiative transitions. Most reported luminescent radicals with high photoluminescent quantum efficiency (PLQE) have a donor-acceptor (D-A•) chemical structure where an electron-donating group is covalently attached to an electron-withdrawing radical core (A•). Understanding the main factors that define the efficiency and stability of D-A• type luminescent radicals remains challenging. Here, we designed and synthesized a series of tri(2,4,6-trichlorophenyl)methyl (TTM) radical derivatives with donor substituents varying by their extent of conjugation and their number of imine-type nitrogen atoms. The experimental results suggest that the luminescence efficiency and stability of the radicals are proportional to the degree of conjugation but inversely proportional to the number of imine nitrogen atoms in the substituents. These experimental trends are very well reproduced by density functional theory calculations. The theoretical results indicate that both the luminescence efficiency and radical stability are related to the energy difference between the charge transfer (CT) and local-excitation (LE) states, which decreases as either the number of imine nitrogen atoms in the substituent increases or its conjugation length decreases.
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Affiliation(s)
- Chen Lu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Eunkyung Cho
- Department of Chemistry and Biochemistry, University of Arizona College of Science, Tucson, AZ, 85721-0088, USA
| | - Zhiyuan Cui
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yuhang Gao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Wenjuan Cao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Jean-Luc Brédas
- Department of Chemistry and Biochemistry, University of Arizona College of Science, Tucson, AZ, 85721-0088, USA
| | - Veaceslav Coropceanu
- Department of Chemistry and Biochemistry, University of Arizona College of Science, Tucson, AZ, 85721-0088, USA
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
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Merschel A, Rottschäfer D, Neumann B, Stammler HG, Ringenberg M, van Gastel M, Demirer TI, Andrada DM, Ghadwal RS. Crystalline Anions Based on Classical N-Heterocyclic Carbenes. Angew Chem Int Ed Engl 2023; 62:e202215244. [PMID: 36398890 PMCID: PMC10107637 DOI: 10.1002/anie.202215244] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/18/2022] [Accepted: 11/18/2022] [Indexed: 11/19/2022]
Abstract
Herein, the first stable anions K[SIPrBp ] (4 a-K) and K[IPrBp ] (4 b-K) (SIPrBp =BpC{N(Dipp)CH2 }2 , IPrBp =BpC{N(Dipp)CH}2 ; Bp=4-PhC6 H4 ; Dipp=2,6-iPr2 C6 H3 ) derived from classical N-heterocyclic carbenes (NHCs) (i.e. SIPr and IPr) have been isolated as violet crystalline solids. 4 a-K and 4 b-K are prepared by KC8 reduction of the neutral radicals [SIPrBp ] (3 a) and [IPrBp ] (3 b), respectively. The radicals 3 a and 3 b as well as [Me-IPrBp ] 3 c (Me-IPrBp =BpC{N(Dipp)CMe}2 ) are accessible as crystalline solids on treatment of the respective 1,3-imidazoli(ni)um bromides (SIPrBp )Br (2 a), (IPrBp )Br (2 b), and (Me-IPrBp )Br (2 c) with KC8 . The cyclic voltammograms of 2 a-2 c exhibit two one-electron reversible redox processes in -0.5 to -2.5 V region that correspond to the radicals 3 a-3 c and the anions (4 a-4 c)- . Computational calculations suggest a closed-shell singlet ground state for (4 a-4 c)- with the singlet-triplet energy gap of 17-24 kcal mol-1 .
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Affiliation(s)
- Arne Merschel
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie, Centrum für Molekulare Materialien, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Dennis Rottschäfer
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie, Centrum für Molekulare Materialien, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany.,Current address: Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Str. 4, Marburg, Germany
| | - Beate Neumann
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie, Centrum für Molekulare Materialien, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Hans-Georg Stammler
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie, Centrum für Molekulare Materialien, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Mark Ringenberg
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Maurice van Gastel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim a. d. Ruhr, Germany
| | - T Ilgin Demirer
- Allgemeine und Anorganische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany
| | - Diego M Andrada
- Allgemeine und Anorganische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany
| | - Rajendra S Ghadwal
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie, Centrum für Molekulare Materialien, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany
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