Coordination Induction-Enhanced Thermally Activated Delayed Fluorescence for Silver(I) Complexes

Donor–acceptor (D–A) type nitrogen-containing compounds represent a key class of materials for constructing thermally activated delayed fluorescence (TADF) emitters. Achieving high-efficiency emission is the first issue in designing D–A-type TADF materials, particularly for applications in doped organic light-emitting diodes. Coordination-induced delayed fluorescence provides an effective strategy to regulate energy levels in these TADF materials, enabling efficient intramolecular ligand charge transfer (ILCT)-type emission. Moreover, metal coordination induces critical improvements, including enhanced spin–orbit coupling effect and shortened radiative lifetimes. Herein, we modulate the energy-level structure of yellow-emitting D–A-type hybrid fluorescence–TADF molecules via Ag(I) coordination, obtaining two Ag(I) complexes exhibiting ILCT-type emission. The coordination environment tunes the energy levels and reduces Δ E ST, leading to a sharp enhancement in hybrid fluorescence–TADF performance. When doped in PMMA films, complex 1 achieves a PLQY of 98% (τ F = 134 ns; τ TADF = 2.7 μs), while complex 2 shows a PLQY of 46% (τ F = 70.7 ns; τ TADF = 2.0 μs). This work establishes a robust strategy to design novel TADF-active metal complexes.