The development of red thermally activated delayed fluorescence (TADF) emitters with the emission peak above 600 nm remains far behind blue and green emitters. Herein, the highly rigid polycyclic acceptors with strong electron-withdrawing ability, integrated by quinoxaline and 1,8-naphthalimideacridine units, were utilized to construct two new red emitters with emission peak at 640 nm. Both target molecules display the twisted configuration to decrease singlet-triplet splitting energy (ΔE_ST) for the TADF property. Red organic light-emitting diodes (OLEDs) employing the emitters achieve the maximum external quantum efficiencies of 5.2% with electroluminescence peaks over 600 nm. This work provides a feasible strategy of the new polycyclic acceptors for developing efficient red TADF emitters.

发射峰在 600 nm 以上的红色热激活延迟荧光 (TADF) 发射器的发展仍远远落后于蓝色和绿色发射器。在此，利用具有强吸电子能力的高刚性多环受体，由喹喔啉和1,8-萘酰亚胺吖啶单元集成，构建了两种发射峰在640 nm的新型红色发射体。两个目标分子都显示出扭曲构型，以降低TADF 特性的单线态-三线态分裂能 (Δ E _{ST )。}采用该发射器的红色有机发光二极管（OLED）实现了5.2%的最大外量子效率电致发光峰值超过 600 nm。这项工作为开发高效的红色 TADF 发射器提供了新型多环受体的可行策略。