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Hojo R, Bergmann K, Hudson ZM. Investigating Hydrogen Bonding in Quinoxaline-Based Thermally Activated Delayed Fluorescent Materials. J Phys Chem Lett 2024; 15:5600-5606. [PMID: 38758029 DOI: 10.1021/acs.jpclett.4c01177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
In recent years, hydrogen bonding (H bonding) as an intramolecular locking strategy has been proposed to enhance photoluminescence, color purity, and photostability in thermally activated delayed fluorescence (TADF) materials. Rigidification as a design strategy is particularly relevant when using electron-deficient N-heterocycles as electron acceptors, because these materials often suffer from poor performance as orange to near-infrared emitters as a result of the energy gap law. To critically evaluate the presence of H bonding in such materials, two TADF-active donor-acceptor dyads, ACR-DQ and ACR-PQ, were synthesized. Despite their potential sites for intramolecular H bonding and emissions spanning yellow to deep red, computational analyses (including frequency, natural bond orbital, non-covalent interaction, and potential energy surface assessments) and crystal structure examinations collectively suggest the absence of H bonding in these materials. Our results indicate that invoking intramolecular H bonding should be done with caution in the design of rigidified TADF materials.
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Affiliation(s)
- Ryoga Hojo
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Katrina Bergmann
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zachary M Hudson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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2
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Cheng ZL, Zhang M, Yuan Y, Wang H, Li J, Zhang J, Li JC, Zhou JY, Wang JS, Liang HZ, Ye J, Wang K, Zhang XH. Intramolecular Hydrogen Bonding Rigidifying Flexible Bridge for Solution- and Vacuum-Processed TSCT-TADF Emitters. Org Lett 2024. [PMID: 38802298 DOI: 10.1021/acs.orglett.4c01493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
To realize strong donor-acceptor face-to-face stacking for efficient through-space charge transfer-type thermally activated delayed fluorescence, a conceptually new design strategy is proposed to couple flexible bridges with adequate rigidity via built-in intramolecular hydrogen bonds (IHBs). The resulting emitter ACE-CN has a planarized benzyl methyl ether bridge self-anchored by the C-H···O IHB and shows a high photoluminescence quantum efficiency of 93%. The solution- and vacuum-processed devices exhibited high external quantum efficiencies of 11.8% and 24.7%, respectively.
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Affiliation(s)
- Zhang-Li Cheng
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Ming Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Yi Yuan
- School of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan 421001, P. R. China
| | - Hui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Jie Li
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Jing Zhang
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Jia-Chen Li
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Jie-Yu Zhou
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Jia-Shen Wang
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Hong-Ze Liang
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Jun Ye
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, P. R. China
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, Jiangsu 215123, P. R. China
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Li Q, Zhao Z, Zhao H, Guo Y, Tong X, Yan S, Ren Z. Enhancing Light-Emitting Efficiency of Blue Through-Space Charge Transfer Emitters via Fixing Configuration Induced by Intramolecular Hydrogen Bonding. ACS APPLIED MATERIALS & INTERFACES 2024; 16:22238-22247. [PMID: 38634459 DOI: 10.1021/acsami.4c01219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Closely aligned configuration of the donor (D) and acceptor (A) is crucial for the light-emitting efficiency of thermally activated delayed fluorescence (TADF) materials with through-space charge transfer (TSCT) characteristics. However, precisely controlling the D-A distance of blue TSCT-TADF emitters is still challenging. Herein, an extra donor (D*) located on the side of the primary donor (D) is introduced to construct the hydrogen bonding with A and thus modulate the distance of D and A units to prepare high-efficiency blue TSCT emitters. The obtained "V"-shaped TSCT emitter presents a minimal D-A distance of 2.890 Å with a highly parallel D-A configuration. As a result, a high rate of radiative decay (>107 s-1) and photoluminescence quantum yield (nearly 90%) are achieved. The corresponding blue organic light-emitting diodes show maximum external quantum efficiencies (EQEmax) of 27.9% with a Commission Internationale de L'Eclairage (CIE) coordinate of (0.16, 0.21), which is the highest device efficiency of fluorene-based blue TSCT-TADF emitters. In addition, the TSCT-TADF emitter-sensitized OLEDs also achieve a high EQEmax of 29.3% with a CIE coordinate of (0.12, 0.16) and a narrow emission.
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Affiliation(s)
- Quanwei Li
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Zhennan Zhao
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Haisong Zhao
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Yumeng Guo
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Xingwen Tong
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China
| | - Shouke Yan
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China
- Key Laboratory of Rubber-Plastics Ministry of Education, Qingdao University of Science & Technology, Qingdao 266042, PR China
| | - Zhongjie Ren
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China
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4
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Zhao T, Jiang S, Wang Y, Hu J, Lin FL, Meng L, Gao P, Chen XL, Lu CZ. Realizing High-Efficiency Orange-Red Thermally Activated Delayed Fluorescence Materials through the Construction of Intramolecular Noncovalent Interactions. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37315213 DOI: 10.1021/acsami.3c04117] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The development of highly efficient orange and red thermally activated delayed fluorescence (TADF) materials for constructing full-color and white organic light-emitting diodes (OLEDs) remains insufficient because of the formidable challenges in molecular design, such as the severe radiationless decay and the intrinsic trade-off between the efficiencies of radiative decay and reverse intersystem crossing (RISC). Herein, we design two high-efficiency orange and orange-red TADF molecules by constructing intermolecular noncovalent interactions. This strategy could not only ensure high emission efficiency via suppression of the nonradiative relaxation and enhancement of the radiative transition but also create intermediate triplet excited states to ensure the RISC process. Both emitters exhibit typical TADF characteristics, with a fast radiative rate and a low nonradiative rate. Photoluminescence quantum yields (PLQYs) of the orange (TPA-PT) and orange-red (DMAC-PT) materials reach up to 94 and 87%, respectively. Benefiting from the excellent photophysical properties and stability, OLEDs based on these TADF emitters realize orange to orange-red electroluminescence with high external quantum efficiencies reaching 26.2%. The current study demonstrates that the introduction of intermolecular noncovalent interactions is a feasible strategy for designing highly efficient orange to red TADF materials.
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Affiliation(s)
- Tianxiang Zhao
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou, Fuzhou, Fujian 350108, 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
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shanshan Jiang
- 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
| | - Yashu Wang
- 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
| | - Jiaxuan Hu
- 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
| | - 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
| | - Lingyi Meng
- 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
| | - Peng Gao
- 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
| | - 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
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou, Fuzhou, Fujian 350108, 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
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou, Fuzhou, Fujian 350108, 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
- University of Chinese Academy of Sciences, Beijing 100049, China
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Bergmann K, Hojo R, Hudson ZM. Uncovering the Mechanism of Thermally Activated Delayed Fluorescence in Coplanar Emitters Using Potential Energy Surface Analysis. J Phys Chem Lett 2023; 14:310-317. [PMID: 36602966 DOI: 10.1021/acs.jpclett.2c03425] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Planarized emitters exhibiting thermally activated delayed fluorescence (TADF) have attracted attention due to their narrow emission spectra, improved photostability, and high quantum yields, but with large singlet-triplet energy gaps (ΔEST) and no heavy atoms, the origin of their TADF remains a subject of debate. Here we prepare two isomeric, coplanar donor-acceptor compounds, with HMAT-2PYM performing dual TADF and room-temperature phosphorescence but with HMAT-4PYM exhibiting only prompt fluorescence. Although conventional TADF design principles suggest that neither isomer should exhibit TADF, we reveal differences in the excited state potential energy surfaces that enable spin-flip processes in only one isomer. We also find that hydrogen bonding is absent between the planar units of these emitters, despite earlier claims of intramolecular hydrogen bonding in similar compounds. Overall, this work demonstrates that potential energy surface analysis is a practical strategy for designing coplanar TADF materials that might otherwise be overlooked by conventional TADF design metrics.
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Affiliation(s)
- Katrina Bergmann
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Ryoga Hojo
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Zachary M Hudson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
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Huang Z, Lei B, Yang D, Ma D, Bin Z, You J. Modified Intramolecular‐Lock Strategy Enables Efficient Thermally Activated Delayed Fluorescence Emitters for Non‐Doped OLEDs. Angew Chem Int Ed Engl 2022; 61:e202213157. [DOI: 10.1002/anie.202213157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Indexed: 11/17/2022]
Affiliation(s)
- Zhenmei Huang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| | - Bowen Lei
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of 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 P. R. 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 P. R. China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
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