Synthesis and Luminescent Properties of Trifluoromethyl-Functionalized Biscyclometalated Gold(III) Complexes

Gold(III) complexes have gained prominence as photofunctional materials due to their tunable photophysical properties and potential in advanced optoelectronic applications. While traditionally gold(III) complexes have been known to exhibit phosphorescence emission, recent advancements have revealed that gold(III) complexes can also display thermally activated delayed fluorescence (TADF), enabling near-unity internal quantum efficiencies and full exciton utilization. However, gold(III) biscyclometalated complexes incorporating trifluoromethyl groups and displaying TADF-type emission have been lacking. We report biscyclometalated gold(III) C^N^C complexes incorporating electron-withdrawing trifluoromethyl (CF₃) groups with TADF-type emission. Both aryl and alkynyl ligands were employed to investigate the balance between structural stability and donor-acceptor spatial separation. Detailed photophysical studies reveal TADF-type emission behavior in these complexes with quantum yields as high as 70% in solution with high radiative rates in the order of 10⁶ s^-1. These complexes exhibit promising photophysical properties suitable for high-efficiency organic light-emitting diode applications, providing valuable design strategies for next-generation TADF emitters based on gold(III) scaffolds.