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Wang W, Gong J, Zhao J, Zhang H, Wen W, Zhao Z, Li YJ, Wang J, Huang CZ, Gao PF. Integration of Wallach's Rule into Intermolecular Charge Transfer: A Visual Strategy for Chiral Purification. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403249. [PMID: 39013078 DOI: 10.1002/advs.202403249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/19/2024] [Indexed: 07/18/2024]
Abstract
Exploring the molecular packing and interaction between chiral molecules, no matter single enantiomer or racemates, is important for recognition and resolution of chiral drugs. However, sensitive and non-destructive analysis methods are lacking. Herein, an intermolecular-charge transfer (ICT) based spectroscopy is reported to reveal the differences in interaction between the achiral acceptor 1,2,4,5-tetracyanobenzene (TCNB) and the chiral donors, including S, R, and racemic naproxen (S/R/rac-NAP). In this process, S-NAP+TCNB and R-NAP+TCNB display a narrower band gap attributed to the newly formed ICT state. In contrast, the mixed rac-NAP and TCNB exhibit almost no significant change due to the strong affinity between the stereoisomers according to the Wallach's rule. Thus, S/R-NAP can be easily distinguished from rac-NAP based on significantly different optical behavior. The single crystal analysis, infrared spectroscopy, fluorescence spectroscopy, and theoretical calculation of naproxen confirm the importance of carboxyl for this differentiation in molecular packing and interaction. In addition, the esterification derivatization of naproxen achieves the manipulation of the intermolecular interaction model of racemates from the absolute Wallach's rule to a coexisting form of Wallach's rule and ICT. Further, visualized chiral purification of naproxen by the simple cocrystallization method is achieved through the collaboration of ICT and Wallach's rule.
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Affiliation(s)
- Wei Wang
- Key Laboratory of Biomedical Analytics, Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
| | - Jianye Gong
- College of Chemistry and Chemical Engineering, Inner Mongolia Key Laboratory of Fine Organic Synthesis, Inner Mongolia University, Hohhot, 010021, China
| | - Jiaqiang Zhao
- Key Laboratory of Biomedical Analytics, Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
| | - Hao Zhang
- Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China
| | - Wei Wen
- Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Yan Jie Li
- Key Laboratory of Biomedical Analytics, Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
| | - Jianguo Wang
- College of Chemistry and Chemical Engineering, Inner Mongolia Key Laboratory of Fine Organic Synthesis, Inner Mongolia University, Hohhot, 010021, China
| | - Cheng Zhi Huang
- Key Laboratory of Biomedical Analytics, Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
| | - Peng Fei Gao
- Key Laboratory of Biomedical Analytics, Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China
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2
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Zhu X, Wang Y, Nadinov I, Thomas S, Gutiérrez-Arzaluz L, He T, Wang JX, Alkhazragi O, Ng TK, Bakr OM, Alshareef HN, Ooi BS, Mohammed OF. Leveraging Intermolecular Charge Transfer for High-Speed Optical Wireless Communication. J Phys Chem Lett 2024; 15:2988-2994. [PMID: 38457267 PMCID: PMC10961838 DOI: 10.1021/acs.jpclett.4c00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/26/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024]
Abstract
Intermolecular charge transfer (CT) complexes have emerged as versatile platforms with customizable optical properties that play a pivotal role in achieving tunable photoresponsive materials. In this study, we introduce an innovative approach for enhancing the modulation bandwidth and net data rates in optical wireless communications (OWCs) by manipulating combinations of monomeric molecules within intermolecular CT complexes. Concurrently, we extensively investigate the intermolecular charge transfer mechanism through diverse steady-state and ultrafast time-resolved spectral techniques in the mid-infrared range complemented by theoretical calculations using density functional theory. These intermolecular CT complexes empower precise control over the -3 dB bandwidth and net data rates in OWC applications. The resulting color converters exhibit promising performance, achieving a net data rate of ∼100 Mb/s, outperforming conventional materials commonly used in the manufacture of OWC devices. This research underscores the substantial potential of engineering intermolecular charge transfer complexes as an ongoing progression and commercialization within the OWC. This carries profound implications for future initiatives in high-speed and secure data transmission, paving the way for promising endeavors in this area.
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Affiliation(s)
- Xin Zhu
- Advanced
Membranes and Porous Materials Center, Division of Physical Science
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Yue Wang
- Photonics
Laboratory, Division of Computer, Electrical, and Mathematical Sciences
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Issatay Nadinov
- Advanced
Membranes and Porous Materials Center, Division of Physical Science
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Materials
Science and Engineering, Physical Science and Engineering Division, King Abdullah University of Science and Technology
(KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Simil Thomas
- Advanced
Membranes and Porous Materials Center, Division of Physical Science
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Luis Gutiérrez-Arzaluz
- Advanced
Membranes and Porous Materials Center, Division of Physical Science
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- KAUST
Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Tengyue He
- Advanced
Membranes and Porous Materials Center, Division of Physical Science
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Jian-Xin Wang
- Advanced
Membranes and Porous Materials Center, Division of Physical Science
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Omar Alkhazragi
- Photonics
Laboratory, Division of Computer, Electrical, and Mathematical Sciences
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Tien Khee Ng
- Photonics
Laboratory, Division of Computer, Electrical, and Mathematical Sciences
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Osman M. Bakr
- KAUST
Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Husam N. Alshareef
- Materials
Science and Engineering, Physical Science and Engineering Division, King Abdullah University of Science and Technology
(KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Boon S. Ooi
- Photonics
Laboratory, Division of Computer, Electrical, and Mathematical Sciences
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Omar F. Mohammed
- Advanced
Membranes and Porous Materials Center, Division of Physical Science
and Engineering, King Abdullah University
of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- KAUST
Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
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3
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Yu YJ, Liu FM, Meng XY, Ding LY, Liao LS, Jiang ZQ. Carbonyl-Containing Thermally Activated Delayed Fluorescence Emitters for Narrow-Band Electroluminescence. Chemistry 2023; 29:e202202628. [PMID: 36250810 DOI: 10.1002/chem.202202628] [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: 08/23/2022] [Indexed: 11/23/2022]
Abstract
Carbonyl-containing derivatives show enduring vitality in the field of thermally activated delayed fluorescence (TADF) materials; they can realize high device efficiency by using both singlet and triplet excitons for electroluminescence. Recently, a system based on fused ketone/amine exhibited huge potential for constructing multi-resonance TADF (MR-TADF) emitters, which exhibit higher narrow-band emission than conventional TADF emitters with twisted donor-acceptor (D-A) structure. Herein, we summarize current research progress in both traditional and MR-type ketone derivatives with TADF characteristics for introducing the molecular design strategy of maintaining high device efficiency while keeping narrow-band emission profile. We hope this review can inspire the emergence of more high-performance narrow-band materials.
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Affiliation(s)
- You-Jun Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, P.R. China
| | - Fu-Ming Liu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, P.R. China
| | - Xin-Yue Meng
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, P.R. China
| | - Ling-Yi Ding
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, P.R. China
| | - Liang-Sheng Liao
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, P.R. China
| | - Zuo-Quan Jiang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, P.R. China
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4
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Jiang W, Zhao G, Tian W, Sun Y. Aggregation-Induced Intermolecular Charge Transfer Emission for Solution-Processable Bipolar Host Material via Adjusting the Length of Alkyl Chain. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27228099. [PMID: 36432201 PMCID: PMC9698787 DOI: 10.3390/molecules27228099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022]
Abstract
Molecules with donor-spacer-acceptor configuration have been developed rapidly given their peculiar properties. How to utilize intermolecular interactions and charge transfers for solution-processed organic light-emitting diodes (OLEDs) greatly relies on molecular design strategy. Herein, soluble luminophores with D-spacer-A motif were constructed via shortening the alkyl chain from nonane to propane, where the alkyl chain was utilized as a spatial linker between the donor and acceptor. The alkyl chain blocks the molecular conjugation and induces the existence of aggregation-induced intermolecular CT emission, as well as the improved solubility and morphology in a solid-state film. In addition, the length of the alkyl chain affects the glass transition temperature, carrier transport and balance properties. The mCP-3C-TRZ with nonane as the spacer shows better thermal stability and bipolar carrier transport ability, so the corresponding solution-processable phosphorescent organic light-emitting diodes exhibit superior external quantum efficiency of 9.8% when using mCP-3C-TRZ as a host material. This work offers a promising strategy to establish a bipolar host via utilizing intermolecular charge transfer process in an aggregated state.
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5
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Zhang Q, Li M, Wang X, Zhang K, Song Y, Fan J, Wang CK, Lin L. Exploration on dual emission mechanism of CPzP and CPzPO with thermally activated delayed fluorescence. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2143447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Qun Zhang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Muzhen Li
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Xiaofei Wang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Kai Zhang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Yuzhi Song
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Jianzhong Fan
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Chuan-Kui Wang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Lili Lin
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
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6
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Zhu Y, Qu C, Ye J, Xu Y, Zhang Z, Wang Y. Donor-Acceptor Type of Fused-Ring Thermally Activated Delayed Fluorescence Compounds Constructed through an Oxygen-Containing Six-Membered Ring. ACS APPLIED MATERIALS & INTERFACES 2022; 14:47971-47980. [PMID: 36219720 DOI: 10.1021/acsami.2c12778] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Nowadays, thermally activated delayed fluorescence (TADF) compounds with a fused-ring core skeleton are getting increasing research interest because of their use in high-performance organic light-emitting diodes (OLEDs). In this study, TADF compounds featuring a D-A-type fused-ring core skeleton are developed. The challenging compatibility of a planarized D-A arrangement and the TADF property is achieved through linking the D and A moieties with two oxygen atoms within a six-membered ring. Compared with a single-oxygen analogue possessing a flexible skeleton and a twisted D-A arrangement, these fused-ring compounds with higher skeleton rigidity show higher photoluminescence quantum yields and narrower emission spectra in toluene and in doped thin films. Their electroluminescent devices achieve high external quantum efficiencies (up to 19.4%), suggesting the potential of rarely achieved D-A-type fused-ring TADF systems to serve as high-performance emitters of OLEDs.
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Affiliation(s)
- Yunlong Zhu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012 P. R. China
| | - Cheng Qu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012 P. R. China
| | - Jianjiang Ye
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012 P. R. China
| | - Yincai Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012 P. R. China
| | - Zuolun Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012 P. R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012 P. R. China
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7
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Zhang D, Wada Y, Wang Q, Dai H, Fan T, Meng G, Wei J, Zhang Y, Suzuki K, Li G, Duan L, Kaji H. Highly Efficient and Stable Blue Organic Light-Emitting Diodes based on Thermally Activated Delayed Fluorophor with Donor-Void-Acceptor Motif. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2106018. [PMID: 35224891 PMCID: PMC9036013 DOI: 10.1002/advs.202106018] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/04/2022] [Indexed: 05/23/2023]
Abstract
Thermally activated delayed fluorophores (TADF) with donor-acceptor (D-A) structures always face strong conjugation between donor and acceptor segments, rendering delocalized new molecular orbitals that go against blue emission. Developing TADF emitters with blue colors, high efficiencies, and long lifetimes simultaneously is therefore challenging. Here, a D-void-A structure with D and A moieties connected at the void-position where the frontier orbital from donor and acceptor cannot be distributed, resulting in nonoverlap of the orbitals is proposed. A proof-of-the-concept TADF emitter with 3,6-diphenyl-9H-carbazole (D) connected at the 3'3-positions of 9H-xanthen-9-one (A), the void carbon-atom with no distribution of the highest occupied molecular orbital (HOMO) of A-segment, realizes more efficient and blue-shifted emission compared with the contrast D-A isomers. The deeper HOMO-2 of A is found to participate into conjugation rather than HOMO, providing a wider-energy-gap. The corresponding blue device exhibits a y color coordinate (CIEy ) of 0.252 and a maximum external quantum efficiency of 27.5%. The stability of this compound is further evaluated as a sensitizer for a multiple resonance fluorophore, realizing a long lifetime of ≈650 h at an initial luminance of 100 cd m-2 with a CIEy of 0.195 and a narrowband emission with a full-width-at-half-maxima of 21 nm.
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Affiliation(s)
- Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Yoshimasa Wada
- Institute for Chemical ResearchKyoto UniversityUjiKyoto611‐0011Japan
| | - Qi Wang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Hengyi Dai
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Tianjiao Fan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Guoyun Meng
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Jinbei Wei
- Beijing National Laboratory for Molecular SciencesCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Yuewei Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Katsuaki Suzuki
- Institute for Chemical ResearchKyoto UniversityUjiKyoto611‐0011Japan
| | - Guomeng Li
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing100084P. R. China
| | - Hironori Kaji
- Institute for Chemical ResearchKyoto UniversityUjiKyoto611‐0011Japan
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Xing Y, Li Z, Baryshnikov GV, Shen S, Ye D, Ågren H, Zhu L. Water Molecular Bridge-Induced Selective Dual Polarization in Crystals for Stable Multi-Emitter. Chem Sci 2022; 13:6067-6073. [PMID: 35685795 PMCID: PMC9132028 DOI: 10.1039/d2sc00908k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 04/25/2022] [Indexed: 11/21/2022] Open
Abstract
In the solid state, the molecular polarization of donor–acceptor (D–A) molecules can be implemented in a simple way via the use of an external polarizing source (e.g., an electric field). However, internal chemical polarization approaches are less studied due to difficulties related to controlling the charge-separation orientation in the solid state. Herein, a series of D–A molecules with both a proton donor and an acceptor were designed. Water-based molecular bridges were then established in their crystal structures, which firmly and alternately connected the proton donor of one molecule and the acceptor of another via an intermolecular H-bond network. In this way, the selective dual polarization of a phenolic hydroxyl group and a pyridinyl group could be achieved, owing to the strengthening of the charge-separation orientation upon the simultaneous deprotonation and protonation of the D–A molecules. This effect led to a 3–5-fold amplification of the molecular dipole moment in the crystal form relative to the monomeric state. On this basis, multi-excitation and multi-emission characteristics were achieved in these charge-separated crystals, endowing them with the ability to visually detect the energy of a light source, covering a wide range of the UV-Vis spectral region. This work provides a practical chemical approach for developing intrinsically polarized systems that can exhibit stable but distinct molecular photophysical properties. In the solid state, the molecular polarization of donor–acceptor (D–A) molecules can be implemented by internal chemical polarization approaches.![]()
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Affiliation(s)
- Yi Xing
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University Shanghai 200438 China
| | - Zhongyu Li
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University Shanghai 200438 China
| | - Glib V Baryshnikov
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University 60174 Norrköping Sweden
| | - Shen Shen
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University Shanghai 200438 China
| | - Danfeng Ye
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University Shanghai 200438 China
| | - Hans Ågren
- Department of Physics and Astronomy, Uppsala University Box 516 SE-751 20 Uppsala Sweden
| | - Liangliang Zhu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University Shanghai 200438 China
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Song Y, Tian M, Yu R, He L. Through-Space Charge-Transfer Emitters Developed by Fixing the Acceptor for High-Efficiency Thermally Activated Delayed Fluorescence. ACS APPLIED MATERIALS & INTERFACES 2021; 13:60269-60278. [PMID: 34881866 DOI: 10.1021/acsami.1c17707] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Through-space charge-transfer (TSCT) emitters have been extensively explored for thermally activated delayed fluorescence (TADF), but arranging various donors and acceptors into rigid cofacial conformations for various efficient TSCT TADF emitters has remained challenging. Here, we report a "fixing acceptor" design to reach various efficient TSCT TADF emitters. By chemically fixing the acceptor (benzophenone) with a rigid spiro-structure and cofacially aligning various donors with the fixed acceptor, a series of efficient TSCT TADF emitters have been developed. Single-crystal structures and theoretical calculations have verified closely packed cofacial donor/acceptor conformations and favorable TSCT in the emitters. In doped films, the emitters afford sky blue to yellow TADF emission, with high photoluminescence efficiencies up to 0.92 and reverse intersystem crossing rates up to 1.0 × 106 s-1. Organic light-emitting diodes using the emitters afford sky blue to yellow electroluminescence with high external quantum efficiencies up to 20.9%. The work opens a new avenue toward a wide variety of efficient TSCT TADF emitters.
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Affiliation(s)
- Yongjun Song
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Mingxing Tian
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Renyou Yu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Lei He
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
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10
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Su R, Huang Z. "H-Type" Like Constructed Dimer: Another Way to Enhance the Thermally Activated Delayed Fluorescence Effect. J Phys Chem Lett 2021; 12:11497-11502. [PMID: 34797082 DOI: 10.1021/acs.jpclett.1c03044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Thermally activated delayed fluorescence (TADF) materials are an essential part of TADF-based organic light-emitting diodes (OLEDs). All the reported methods to improve the performance of TADF materials were focused on achieving a high reverse intersystem crossing rate (kRISC) and oscillator strength (f), but most of them were studies on single molecular states. In this paper, we have discovered a new dimer architecture called the "H-type" like dimer and proved that the "H-type" like dimer is another way to improve the performance of TADF materials by calculation and experiment. The calculated energy levels of excited states only provided 1.72-5.46% relative errors (RE) compare with the measured values, which indicated that the methods we chose were suitable for predicting the properties. The intermolecular interactions of the "H-type" like dimer endow it with much larger f and kRISC properties than monomer states, proving that the "H-type" like dimer could improve the performance of TADF emitters.
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Affiliation(s)
- Rongchuan Su
- Department of Pharmacology, North Sichuan Medical College, Nanchong 637100, China
| | - Zhenmei Huang
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
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11
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Huang T, Wang Q, Xiao S, Zhang D, Zhang Y, Yin C, Yang D, Ma D, Wang Z, Duan L. Simultaneously Enhanced Reverse Intersystem Crossing and Radiative Decay in Thermally Activated Delayed Fluorophors with Multiple Through-space Charge Transfers. Angew Chem Int Ed Engl 2021; 60:23771-23776. [PMID: 34405502 DOI: 10.1002/anie.202109041] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/04/2021] [Indexed: 12/21/2022]
Abstract
Thermally activated delayed fluorescence (TADF) materials with through-space charge transfers (CT) have attracted particularly interest recently. However, the slow reverse intersystem crossing (RISC) and radiative decay always limit their electroluminescence performances. Herein, TADF molecules with ortho-linked multiple donors-acceptor (ortho-Dn -A) motif are developed to create near-degenerate excited states for the reinforcement of spin-orbit coupling. The incorporation of both through-bond and through-space CT enlarges oscillator strength. The optimal ortho-D3 -A compound exhibits a photoluminescence quantum yield of ca. 100 %, a high RISC rate of 2.57×106 s-1 and a high radiative decay rate of 1.00×107 s-1 simultaneously. With this compound as the sensitizer, a TADF-sensitized-fluorescent organic light-emitting diode shows a maximum external quantum efficiency of 31.6 % with an ultrapure green Commission Internationale de L'Eclairage y coordinate value of 0.69.
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Affiliation(s)
- Tianyu Huang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Qi Wang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China.,School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Shu Xiao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Dongdong Zhang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yuewei Zhang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Chen Yin
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Dezhi Yang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Dongge Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Zhaohui Wang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Lian Duan
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China.,Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China
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12
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Wang R, Li Z, Hu T, Tian L, Hu X, Liu S, Cao C, Zhu ZL, Tan JH, Yi Y, Wang P, Lee CS, Wang Y. Two-Channel Space Charge Transfer-Induced Thermally Activated Delayed Fluorescent Materials for Efficient OLEDs with Low Efficiency Roll-Off. ACS APPLIED MATERIALS & INTERFACES 2021; 13:49066-49075. [PMID: 34613700 DOI: 10.1021/acsami.1c12627] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Enhancing the reverse intersystem crossing (RISC) process of thermally activated delayed fluorescent (TADF) emitters is an effective approach to realize efficient organic light-emitting diodes (OLEDs) with low efficiency roll-off. In this work, we designed two novel TADF emitters, SAT-DAC and SATX-DAC, via a spiro architecture. Efficient maximum external quantum efficiencies (EQEs) of 22.6 and 20.9% with reduced efficiency roll-off (EQEs of 17.9 and 17.0% at 1000 cd m-2) were achieved via a "two-RISC-channel" strategy. X-ray diffraction shows close donor (D)/acceptor (A) spacing and suitable D/A orientation in crystals of the two emitters favoring both intra- and intermolecular through-space charge transfer (TSCT) processes. Transient photoluminescence decay measurements show that both emitters have two RISC channels leading to kISCT exceeding 106 s-1. These results suggest that the "two-RISC-channel" design can be a novel approach for enhancing performance of TADF emitters, in particular at high excitation densities.
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Affiliation(s)
- Ruifang Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, and TIPC-CityU Joint Laboratory of Functional Materials and Device, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Zhiyi Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, and TIPC-CityU Joint Laboratory of Functional Materials and Device, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Taiping Hu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Lei Tian
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, and TIPC-CityU Joint Laboratory of Functional Materials and Device, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xiaoxiao Hu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, and TIPC-CityU Joint Laboratory of Functional Materials and Device, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shihao Liu
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, P. R. China
| | - Chen Cao
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, P. R. China
| | - Ze-Lin Zhu
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, P. R. China
| | - Ji-Hua Tan
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, P. R. China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Pengfei Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, and TIPC-CityU Joint Laboratory of Functional Materials and Device, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chun-Sing Lee
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, P. R. China
| | - Ying Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, and TIPC-CityU Joint Laboratory of Functional Materials and Device, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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13
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Huang T, Wang Q, Xiao S, Zhang D, Zhang Y, Yin C, Yang D, Ma D, Wang Z, Duan L. Simultaneously Enhanced Reverse Intersystem Crossing and Radiative Decay in Thermally Activated Delayed Fluorophors with Multiple Through‐space Charge Transfers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202109041] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Tianyu Huang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China
| | - Qi Wang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China
- School of Materials Science and Engineering Tsinghua University Beijing 100084 China
| | - Shu Xiao
- Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China
| | - Dongdong Zhang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China
| | - Yuewei Zhang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China
| | - Chen Yin
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China
| | - Dezhi Yang
- Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China
| | - Dongge Ma
- Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China
| | - Zhaohui Wang
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China
| | - Lian Duan
- Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China
- Center for Flexible Electronics Technology Tsinghua University Beijing 100084 China
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14
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Wu P, Xie FM, Wei HX, Li YQ, Dai GL, Wang Y, Tang JX, Zhao X. Thermally activated delayed fluorescent emitters based on 3-(phenylsulfonyl)pyridine. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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15
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He L, Bai R, Yu R, Meng X, Tian M, Wang X. Donor/Acceptor Pairs Created by Electrostatic Interaction: Design, Synthesis, and Investigation on the Exciplex Formed Within the Pair. Angew Chem Int Ed Engl 2021; 60:6013-6020. [PMID: 33331060 DOI: 10.1002/anie.202013332] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/11/2020] [Indexed: 12/23/2022]
Abstract
Exciplexes formed between donors and acceptors have been widely explored but isolating them from each other and tuning the interaction between the donor and acceptor have remained challenges. Here, we report donor/acceptor (D/A) pairs created by electrostatic interaction between a carbazole-based anionic donor and a 1,3,5-triazine-based cationic acceptor and the exciplex formed within the pair. In a diluted film, the D/A pair affords an isolated exciplex which shows thermally activated delayed fluorescence (TADF). By changing the anchoring position of the imidazolium cation in the cationic acceptor, interactions between the donor and acceptor can be changed. Compared to the conventional exciplex formed in a neat film, the isolated exciplex exhibits a substantially higher luminescence efficiency. The D/A pairs show intriguing mechanochromic luminescence and mechanical grinding-induced/reinforced TADF in the solid state and promising performances as emitters in organic light-emitting diodes.
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Affiliation(s)
- Lei He
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Rubing Bai
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Renyou Yu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Xianwen Meng
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Mingxing Tian
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Xiaoxiang Wang
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
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16
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He L, Bai R, Yu R, Meng X, Tian M, Wang X. Donor/Acceptor Pairs Created by Electrostatic Interaction: Design, Synthesis, and Investigation on the Exciplex Formed Within the Pair. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202013332] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Lei He
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis College of Chemistry Central China Normal University Wuhan 430079 P. R. China
| | - Rubing Bai
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis College of Chemistry Central China Normal University Wuhan 430079 P. R. China
| | - Renyou Yu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis College of Chemistry Central China Normal University Wuhan 430079 P. R. China
| | - Xianwen Meng
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis College of Chemistry Central China Normal University Wuhan 430079 P. R. China
| | - Mingxing Tian
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis College of Chemistry Central China Normal University Wuhan 430079 P. R. China
| | - Xiaoxiang Wang
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis College of Chemistry Central China Normal University Wuhan 430079 P. R. China
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17
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Li X, Shen S, Zhang C, Liu M, Lu J, Zhu L. Small-molecule based thermally activated delayed fluorescence materials with dual-emission characteristics. Sci China Chem 2021. [DOI: 10.1007/s11426-020-9908-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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18
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Etherington MK. Thermally Activated Delayed Fluorescence: Beyond the Single Molecule. Front Chem 2020; 8:716. [PMID: 33195010 PMCID: PMC7531616 DOI: 10.3389/fchem.2020.00716] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 07/13/2020] [Indexed: 11/30/2022] Open
Abstract
Emitters that exhibit thermally activated delayed fluorescence (TADF) are of interest for commercial applications in organic light-emitting diodes (OLEDs) due to their ability to achieve internal quantum efficiency of 100%. However, beyond the intrinsic properties of these materials it is important to understand how the molecules interact with each other and when these interactions may occur. Such interactions lead to a significant red shift in the photoluminescence and electroluminescence, making them less practicable for commercial use. Through summarizing the literature, covering solid-state solvation effects and aggregate effects in organic emitters, this mini review outlines a framework for the complete study of TADF emitters formed from the current-state-of-the-art techniques.
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Affiliation(s)
- Marc K. Etherington
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle upon Tyne, United Kingdom
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19
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Sequential determination of cerium (IV) ion and ascorbic acid via a novel organic framework: A subtle interplay between intramolecular charge transfer (ICT) and aggregated-induced-emission (AIE). J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112705] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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20
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Lu Q, Ma X, Gao T, Xie S, Qu F. Strongly enhanced luminous efficiency of organic light emitting diodes in molecular heterojunctions. Phys Chem Chem Phys 2019; 21:12924-12930. [PMID: 31165113 DOI: 10.1039/c9cp02000d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a comprehensive theory based on the extended Su-Schrieffer-Heeger (SSH) model to study the interconversion from the dark triplet exciton state to a bright singlet one in molecular heterojunctions, containing both intrachain and interchain excitons. By studying the spin mixing and the projection of excitons onto the pure singlet and triplet excitons, unlike usual methods, we found that the internal electroluminescent quantum efficiency, which is largely determined by the singlet fraction, can be widely tuned by the spin-orbit coupling strength, the intensity of hyperfine interaction, electron-phonon coupling and the site energy offset of the two chains constituting the molecular heterojunctions. In addition, the interchain excitons possess a higher fraction of singlet states in comparison with the intrachain excitons. Remarkably, it can reach up to 52% by proper choice of the above-mentioned physical parameters. Our results outline a novel approach to further improve the luminous efficiency of organic light emitting diodes.
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Affiliation(s)
- Qiuxia Lu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
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21
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Liu J, Zhou K, Wang D, Deng C, Duan K, Ai Q, Zhang Q. Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet-Triplet Splitting With Large Fluorescence Rate. Front Chem 2019; 7:312. [PMID: 31165054 PMCID: PMC6536661 DOI: 10.3389/fchem.2019.00312] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/18/2019] [Indexed: 01/21/2023] Open
Abstract
Metal-free thermally activated delayed fluorescence (TADF) emitters have emerged as promising candidate materials for highly efficient and low-cost organic light-emitting diodes (OLEDs). Here, a novel acceptor 2-cyanopyrazine is selected for the construction of blue TADF molecules via computer-assisted molecular design. Both theoretical prediction and experimental photophysical data indicate a small S1-T1 energy gap (ΔEST) and a relative large fluorescence rate (kF) in an o-phenylene-bridged 2-cyanopyrazine/3,6-di-tert-butylcarbazole compound (TCzPZCN). The kF value of 3.7 × 107 s−1 observed in a TCzPZCN doped film is among the highest in the TADF emitters with a ΔEST smaller than 0.1 eV. Blue TADF emission is observed in a TCzPZCN doped film with a short TADF lifetime of 1.9 μs. The OLEDs using TCzPZCN as emitter exhibit a maximum external quantum efficiency (EQE) of 7.6% with low-efficiency roll-off. A sky-blue device containing a derivative of TCzPZCN achieves an improved EQE maximum of 12.2% by suppressing the non-radiative decay at T1.
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Affiliation(s)
- Junyuan Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Keren Zhou
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Dan Wang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Chao Deng
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Ke Duan
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Qi Ai
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Qisheng Zhang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
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