A Donor–Acceptor Cage for Thermally Activated Delayed Fluorescence: toward a New Kind of TADF Exciplex Emitters
Lihua Chen, Chuanlong Li, Enguang Fu, Mengyang Li, Yoshiaki Kuboi, Zi-Ying Li, Zhenghong Chen, Jiaolong Chen, Xuelong Liu, Xun Tang, Lucas Frédéric, François Maurel, Chihaya Adachi, Fabrice Mathevet, Shaodong Zhang
Abstract
We present the rational design of an organic cage combining an electron-donating (D) triazatruxene and electron-accepting (A) triphenyl triazine connected by three electronically inert pillars. This controlled architecture leads to a precise spatial separation and cofacial alignment of the D and A motifs. Such an architecture induces an efficient intramolecular through-space charge transfer (TSCT), providing a small singlet–triplet energy difference (Δ E ST ) of 0.049 eV, and thus gives rise to a thermally activated delayed fluorescence (TADF) macrocyclic exciplex emitter.