A novel donor moiety 9,9,9 ' 9 '-tetramethyl-9,9 ' 10,10 '-tetrahydro-2,10 '-biacridineviaone-pot C-H arylation for TADF emitters and their application in highly efficient solution-processable OLEDs
A novel donor moiety 9,9,9 ' 9 '-tetramethyl-9,9 ' 10,10 '-tetrahydro-2,10 '-biacridineviaone-pot C-H arylation for TADF emitters and their application in highly efficient solution-processable OLEDs
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DOI：
10.1039/d0tc01612h
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发表时间：
2020
影响因子：
6.4
通讯作者：
Wang Yafei
中科院分区：
文献类型：
--
作者：
Liu Yuchao;Yin Zheng;Wang Xiangbing;Baranoff Etienne;Zhou Di;Zhang Kai;Ren Zhongjie;Wang Shengyue;Zhu Weiguo;Wang Yafei
9，10-二氢吖啶具有良好的给电子性质和化学修饰潜力，是热激活延迟荧光（TADF）分子的常用给电子单元。然而，很少有人探索吖啶单元2/7位的官能化。本论文通过一锅法C-H芳基化反应合成了新型给体9，9，9 ′9′-四甲基-9，9 ′ 10，10 ′-四氢-2，10 ′-联吖啶（BDMAc）。然后引入不同的受体片段二苯砜（DPS）、二苯甲酮（BPO）和1，3，5-三嗪（TRZ），合成了三种给体-受体分子：DPS-BDMAc、BPO-BDMAc和TRZ-BDMAc。单晶X射线衍射和理论计算表明，这些分子具有扭曲的分子几何形状和小的单重态和三重态激发态之间的能隙。所有分子在溶液和固体状态下都表现出发射峰在480-600 nm之间的TADF性质，沿着在固体状态下具有69-89%的高发射效率。基于这些分子的溶液处理的有机发光二极管（OLED）以25wt%掺杂剂浓度制备。虽然器件显示出效率下降，但基于BPO-BDMAc的器件获得了23%的最大EQE和7173 cd m-2的亮度。这项研究表明，这种新的吖啶基团的设计TADF分子的有效的解决方案可加工的OLED的潜力。
9,10-Dihydroacridine is a very popular donor unit for the construction of thermally activated delayed fluorescence (TADF) molecules due to its good electron-donating properties and potential for chemical modifications. However, the functionalization of the 2/7-positions of the acridine unit has rarely been explored. In this contribution, the novel donor moiety 9,9,9′9′-tetramethyl-9,9′10,10′-tetrahydro-2,10′-biacridine (BDMAc) was prepared via a one-pot C–H arylation procedure. Different acceptor fragments, diphenylsulfone (DPS), benzophenone (BPO) and 1,3,5-triazine (TRZ), were then introduced to synthesize three donor–acceptor molecules: DPS-BDMAc, BPO-BDMAc and TRZ-BDMAc. Single crystal X-ray diffraction and theoretical calculations show that these molecules possess twisted molecular geometries and small energy gaps between the singlet and triplet excited states. All molecules exhibit TADF properties with emission peaks between 480–600 nm in both solution and solid states, along with a high emission efficiency of 69–89% in the solid state. Solution-processed organic light-emitting diodes (OLEDs) based on these molecules were prepared with 25 wt% dopant concentration. Although the devices showed efficiency roll-off, a promising maximum EQE of ∼23% and a luminance of 7173 cd m−2 were obtained for the BPO-BDMAc-based device. This research demonstrates the potential of this novel acridine group for designing TADF molecules for efficient solution-processable OLEDs.