化学学报 ›› 2023, Vol. 81 ›› Issue (8): 891-897.DOI: 10.6023/A23040187 上一篇    下一篇

所属专题: 庆祝《化学学报》创刊90周年合辑

研究论文

新型双极传输特性橙光铱(III)配合物的设计、合成及其电致发光

陶鹏a,b,*(), 郑小康a,c, 王国良c, 盛星浩a,b, 姜贺a,b, 李文桃a,b, 靳继彪a,b, 王瑞鸿a, 苗艳勤c,*(), 王华c, 黄维扬a,b,*()   

  1. a 香港理工大学 应用生物及化学科技学系 中国香港
    b 香港理工大学深圳研究院 深圳 518057
    c 太原理工大学 新材料界面科学与工程教育部重点实验室 太原 030024
  • 投稿日期:2023-04-29 发布日期:2023-09-14
  • 作者简介:
    庆祝《化学学报》创刊90周年.
  • 基金资助:
    项目受国家科技部重点研发计划(2022YFE0104100); 国家自然科学基金(61905120); 香港研究资助局(PolyU 153058/19P); 研究助理教授科研启动基金(P0035922); 香港理工大学(YXB8); 智慧能源研究院(CDAQ); 欧雪明能源讲座教授(847S); 山西省科技创新人才团队项目(202204051001013)

Novel Bipolar Orange Emissive Iridium(III) Complexes: Design, Synthesis, and Electroluminescence

Peng Taoa,b(), Xiaokang Zhenga,c, Guoliang Wangc, Xinghao Shenga,b, He Jianga,b, Wentao Lia,b, Jibiao Jina,b, Sui-Hung Wonga, Yanqin Miaoc(), Hua Wangc, Wai-Yeung Wonga,b()   

  1. a Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, China
    b The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057
    c Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024
  • Received:2023-04-29 Published:2023-09-14
  • Contact: *E-mail: pengtao@polyu.edu.hk; miaoyanqin@tyut.edu.cn; wai-yeung.wong@polyu.edu.hk
  • About author:
    Dedicated to the 90th anniversary of Acta Chimica Sinica.
  • Supported by:
    National Key R&D Program of China(2022YFE0104100); National Natural Science Foundation of China(61905120); Hong Kong Research Grants Council(PolyU 153058/19P); Start-up Fund for RAPs under the Strategic Hiring Scheme(P0035922); Hong Kong Polytechnic University(YXB8); Research Institute for Smart Energy(CDAQ); Miss Clarea Au for the Endowed Professorship in Energy(847S); Science and Technology Innovation Talent Team Project of Shanxi Province(202204051001013)

白光有机发光二极管(OLEDs)作为新型固态照明器件的有力候选者, 高性能橙光材料是实现高品质互补色白光OLEDs的关键因素之一. 此工作中, 将具有空穴传输特性的咔唑基团通过大扭转角连接方式引入2-苯基-4-甲基喹啉中形成新型双极性环金属配体, 分别使用2,2,6,6-四甲基-3,5-庚二酮和吡啶-2-甲酸作为辅助配体, 制备了两例新型咔唑功能化的双极传输特性橙光铱(III)配合物(Ir1Ir2). 通过核磁共振氢谱、碳谱和质谱确认了新型环金属配体和配合物的分子结构, 进一步通过X射线单晶衍射表征了环金属配体和配合物Ir1的结构. 配合物Ir1属于正交晶系, 空间群为P212121, 晶胞参数分别为α=β=γ=90o, a=1.271 nm, b=1.522 nm, c=3.161 nm. 室温下, 在除氧甲苯中, Ir1Ir2显示强的宽谱带橙光发射, 磷光峰值分别位于587和570 nm, 光致发光量子效率分别达到69%和74%, 磷光寿命分别为1.50和1.62 μs. 重要的是, 这两例橙光配合物不仅具有宽的发射半峰宽(83和88 nm), 且具备双极传输特性. 基于配合物Ir2的橙光器件的电致发光峰值位于569 nm, 发射半峰宽达到86 nm, 最高亮度为4826 cd/m2, 峰值外量子效率、电流效率和功率效率分别达到15%、35.7 cd•A-1和23.4 lm•W-1. 结果表明: 通过大扭转角连接方式引入空穴传输基团的分子设计策略可实现高性能双极传输特性的橙光铱(III)配合物, 将在互补色白光器件方面具有重要应用潜力.

关键词: 铱(III)配合物, 咔唑, 电致发光, 磷光, 双极传输

White organic light-emitting diodes (OLEDs) are promising candidates for novel solid-state lighting devices, and high-performance orange light-emitting materials are one of the key factors to realize high-performance complementary color white OLEDs. In this work, we designed a new bipolar cyclometalating ligand by incorporating carbazole moiety with hole-transport ability into 2-phenyl-4-methylquinoline with a large torsion angle. Based on this carbazole-bearing cyclometalating ligand, a pair of orange emissive iridium(III) complexes (Ir1 and Ir2) showing bipolar transport ability are prepared by selecting 2,2,6,6-tetramethylheptane-3,5-dione and picolinic acid as ancillary ligands. Two complexes and the corresponding cyclometalating ligand are well characterized by 1H and 13C nuclear magnetic resonance spectrometry, and mass spectrometry, and the new bipolar cyclometalating ligand and complex Ir1 are also confirmed by X-ray diffraction analysis. The single crystals of Ir1 crystallized in the orthorhombic space group P212121. Its unit cell parameters are α=β=γ=90°, a=1.271 nm, b=1.522 nm, c=3.161 nm. In O2-free toluene solution at room temperature, both complexes exhibit intense orange phosphorescence (587 nm for Ir1, 570 nm for Ir2) with high photoluminescent quantum yields of 69% and 74% and with short lifetimes of 1.50 and 1.62 μs. Most importantly, they not only show relatively broad full width at half maximum (FWHM) of 83 nm for Ir1 and 88 nm for Ir2 in their emission spectra but also possess bipolar transport ability, which will be beneficial to realize high-performance electroluminescence. Complex Ir2 is selected as the dopant to fabricate orange OLEDs. The as-prepared OLED realizes a broad orange emission at 569 nm with FWHM of 86 nm, maximum brightness of 4826 cd•m-2, external quantum efficiency (EQE) of 15%, current efficiency of 35.7 cd•A-1, and power efficiency of 23.4 lm•W-1. The results demonstrate that the new bipolar orange emissive iridium(III) complexes designed by incorporating carbazole moiety with hole-transport ability into the cyclometalating ligand with a large torsion angle will be the promising candidates for the future design of high-performance white organic light-emitting diodes.

Key words: iridium(III) complex, carbazole, electroluminescence, phosphorescence, bipolar charge-transport