Izumi Saika, Higginbotham Heather F, Nyga Aleksandra, Stachelek Patrycja, Tohnai Norimitsu, Silva Piotr de, Data Przemyslaw, Takeda Youhei, Minakata Satoshi
School of Chemistry , Monash University , Clayton , Victoria 3800 , Australia.
Faculty of Chemistry , Silesian University of Technology , M. Strzody 9 , Gliwice 44-100 , Poland.
J Am Chem Soc. 2020 Jan 22;142(3):1482-1491. doi: 10.1021/jacs.9b11578. Epub 2020 Jan 10.
A new class of thermally activated delayed fluorescent donor-acceptor-donor-acceptor (D-A-D-A) π-conjugated macrocycle comprised of two U-shaped electron-acceptors (dibenzo[,]phenazine) and two electron-donors (,'-diphenyl--phenyelendiamine) has been rationally designed and successfully synthesized. The macrocyclic compound displayed polymorphs-dependent conformations and emission properties. Comparative studies on physicochemical properties of the macrocycle with a linear surrogate have revealed significant effects of the structural cyclization of the D-A-repeating unit, including more efficient thermally activated delayed fluorescence (TADF). Furthermore, an organic light-emitting diode (OLED) device fabricated with the macrocycle compound as the emitter has achieved a high external quantum efficiency (EQE) up to 11.6%, far exceeding the theoretical maximum (5%) of conventional fluorescent emitters and that with linear analogue (6.9%).
一类新型的热激活延迟荧光供体-受体-供体-受体（D-A-D-A）π共轭大环化合物已被合理设计并成功合成，该大环由两个U形电子受体（二苯并[，]吩嗪）和两个电子供体（，'-二苯基-苯二胺）组成。大环化合物表现出多晶型依赖性的构象和发光特性。对大环化合物与其线性类似物的物理化学性质进行的比较研究表明，D-A重复单元的结构环化具有显著影响，包括更有效的热激活延迟荧光（TADF）。此外，以大环化合物作为发光体制造的有机发光二极管（OLED）器件实现了高达11.6%的高外量子效率（EQE），远远超过传统荧光发光体的理论最大值（5%）以及线性类似物的外量子效率（6.9%）。
