Meng Li,* Yanwei Liu, Ruihong Duan, Xiaofang Wei, Yuanping Yi, Ying Wang,* and Chuan-Feng Chen*

A new kind of aromatic imide-based thermally activated delayed fluorescence (TADF) materials with twisted donor-acceptor-donor skeleton were efficiently synthesized, which exhibited excellent thermal stability and high photoluminescence quantum yields. The small ∆E_ST (< 0.1 eV) along with the obvious temperature dependent delayed component of transient photoluminescence (PL) spectra demonstrated their excellent TADF properties. Moreover, the performances of organic light emitting diodes using TADF materials AI-Cz and AI-TBCz as dopants were particularly outstanding with the external quantum efficiencies up to 23.2 % and 21.1 %, respectively.

This work has been published in Angew. Chem. Int. Ed. 2017, 56, 8818-8822.