Copper‐Mediated C–H Cyclization of Heterocycles: Facile Access to Multiple Resonance Thermally Activated Delayed Fluorescence Materials

Abstract Reported herein is the first example of a copper‐mediated C─H cyclization of heterocycles to construct structurally diverse carbonyl‐bridged triphenylamine compounds with multiple resonance thermally activated delayed fluorescence (TADF) characteristics. The one‐pot synthesis method exhibits a broad substrate scope and opens a new avenue for rapidly screening high‐performance organic TADF luminescent materials. Novel organic TADF single‐molecule white‐light material 5g with anti‐Kasha dual‐emission character is the first time developed herein and shows a Commission Internationale de l’Eclairage (CIE) coordinate of (0.33, 0.35) in the thin film, and can be used to fabricate robust and low cost organic white light‐emitting diodes (LED). Furthermore, the anti‐Kasha dual‐emission material 5g is fabricated as water‐dispersed nanoparticles (NPs)NPs, which can be efficiently endocytosed into the HeLa cells and dual emission imaging in living cells, and be used in two‐channel emission intensity ratio imaging to observe the intercellular structure.