?:abstract
|
-
We report a series of two-coordinate Au(I) and Cu(I) complexes (3a-3b and 5a-5b) as new organometallic thermally activated delayed fluorescence (TADF) emitters, which were based on the carbene-metal-carbazole model with pyridine-fused-1,2,3-triazolylidene (PyTz) ligand. The PyTz features small steric hindrance and low-energy LUMO (LUMO = -1.47 eV) locating over the π* orbitals of the whole ligand, which facilitates the intermolecular charge transfer (CT) between a donor (carbazole) and an accepter (PyTz). These compounds exhibit efficient TADF with microsecond lifetimes. Temperature-dependent PL kinetics of 3a supports a rather small energy gap between S1 and T1 (ΔES1-T1 = 60 meV). Further experiments reveal that there exist dual-emission properties from a monomer-dimer equilibrium in the solution, exhibiting single-component multicolor emission from blue to orange including white-light emission.
|