Mononuclear Yb(Ⅲ) complexes coordinated by polycyclic aromatic carboxylates for electroluminescence and anti-counterfeiting applications

The luminescent performance of ytterbium complexes is comparatively unsatisfactory due to the quenching effect of high energy N-H/O-H bonds, which exist in solvent molecules. To suppress this quenching, three ligands were designed that could prevent solvent molecules from directly coordinating to Yb 3+ . These ligands were synthesized through simple and low-cost procedures. X-ray single-crystal diffraction data confirmed there is no direct coordination interaction between solvent molecules and Yb 3+ , achieving the predetermined structural design purpose. Among these complexes, [Yb(DCP) 2 ](DIEA) exhibited quantum yield (QY) of 1.34% and a luminescent lifetime of 95 μs in CD 3 OD. The thermodynamic feasibility of ligand-sensitized luminescence of central ion through internal redox process was demonstrated. Additionally, preliminary investigations verified its application potential in solution-processed OLED with the maximum irradiance up to 237,926 μW/m 2 and its utility in anti-counterfeiting applications.