Chen Dongyang, Kusakabe Yu, Ren Yongxia, Sun Dianming, Rajamalli Pachaiyappan, Wada Yoshimasa, Suzuki Katsuaki, Kaji Hironori, Zysman-Colman Eli
Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, U.K.
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
J Org Chem. 2021 Sep 3;86(17):11531-11544. doi: 10.1021/acs.joc.1c01101. Epub 2021 Jul 29.
Three multichromophore thermally activated delayed fluorescence (TADF) molecules, , , and , were synthesized and characterized. These molecules were designed by connecting the TADF moiety 4,5-di(9-carbazol-9-yl)phthalonitrile () to different positions of a central benzene ring scaffold. Three highly soluble emitters all exhibited near-quantitative photoluminescence quantum yields (Φ) in toluene. High Φs were also achieved in doped films, 59 and 70% for and in 10 wt % DPEPO doped film, respectively, and 54% for in 20 wt % doped CBP films. The rate constant of reverse intersystem crossing () for and in DPEPO films reached 1.1 × 10 and 0.7 × 10 s, respectively, and for in the CBP film reached 1.7 × 10 s. A solution-processed organic light-emitting diode based on exhibited a sky-blue emission with CIE coordinates of (0.22, 0.44) and achieved a maximum external quantum efficiency of 7.1%.
合成并表征了三种多发色团热激活延迟荧光（TADF）分子，即 、 和 。这些分子是通过将TADF部分4,5-二（9-咔唑-9-基）邻苯二甲腈（ ）连接到中心苯环支架的不同位置而设计的。三种高溶解性发光体在甲苯中均表现出近乎定量的光致发光量子产率（Φ）。在掺杂薄膜中也实现了高量子产率，在10 wt% DPEPO掺杂薄膜中， 和 的量子产率分别为59%和70%，在20 wt%掺杂CBP薄膜中， 的量子产率为54%。在DPEPO薄膜中， 和 的反向系间窜越速率常数（ ）分别达到1.1×10 和0.7×10 s，在CBP薄膜中， 的 达到1.7×10 s。基于 的溶液处理有机发光二极管发出天空蓝色光，CIE坐标为（0.22, 0.44），最大外量子效率达到7.1%。
