Largely Color-Tuning Prompt and Delayed Fluorescence: Dinuclear Cu(I) Halide Complexes with -Amines and Phosphines.

Luminescent copper(I) halide complexes with bi- and tridentate rigid ligands have gained wide research interests. In this paper, six tetracoordinate dinuclear copper(I) halide complexes, CuX(ppda) [ppda = 2-[2-(dimethylamino)phenyl(phenyl)phosphino]-,-dimethylaniline, X = I (), Br (), Cl ()] and CuX(pfda) [pfda = 2-[2-(dimethylamino)-4-(trifluoromethyl)phenyl(phenyl)phosphino]-,-dimethyl-5-trifluoromethylaniline, X = I (), Br (), Cl ()], were successfully prepared and systematically characterized on their structures and photophysical properties. Complexes - have a centrosymmetric form with a planar CuX unit, and complex has a mirror symmetry form with a butterfly-shaped CuX. Solid complexes , , and emit delayed fluorescence at room temperature, intense blue to greenish yellow (λ = 443-570 nm) light, and their peak wavelengths are located at 443-570 nm with microsecond lifetimes (τ = 0.4-19.2 μs, Φ = 0.05-0.48). Complexes , , and show prompt fluorescence, very weak yellowish green to yellow (λ = 534-595 nm) emission with peak wavelengths at 534-595 nm, and lifetimes in nanoseconds (τ = 4.4-9.3 ns, Φ < 0.0001). (Metal + halide) to ligand and intraligand charge transitions are the main origin of the emission of the complexes. Solution-processed, complex--based nondoped and doped devices emit yellow green light with CIE coordinated at (0.41, 0.51), a maximum EQE up to 0.17%, and luminance reaching 75.52 cd/m.