Thermally Activated Delayed Fluorescence from d¹⁰ -Metal Carbene Complexes through Intermolecular Charge Transfer and Multicolor Emission with a Monomer-Dimer Equilibrium.

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

SUBMITTER: Cao L 

PROVIDER: S-EPMC7839463 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature