Luminescence of Zn-Yb dinuclear Schiff base complex: Enhanced NIR emission by modification with larger conjugated light-harvesting moieties

Near-Infrared Ytterbium Complexes Based on Polycyclic Aromatic Dicarboxylate Ligands and the Solution-Processed NIR OLED with Irradiance up to 110,284 μW/m2

Since the O-H and N-H oscillators of solvent molecules attached to ytterbium ion (Yb3+) and C-H oscillators existing in the inner coordination sphere of Yb3+ would quench the excited energy of Yb(III), which leads to low quantum yields (QYs) of Yb(III) complexes, we aimed to design a ligand that could block solvent molecules and C-H oscillators out of the first coordination sphere of Yb3+. Herein, a series of novel polycyclic aromatic dicarboxylate ligands are designed and synthesized to effectively protect Yb3+ from solvent molecules and efficiently sensitize Yb3+ luminescence, while the cost and sophistication of the synthesis are satisfactory. Therein, [Yb(MO-DPyPDA)2](DIEA) exhibited a considerable QY of 5.20% and a long luminescent lifetime of 102 μs in CD3OD. The single-crystal structure demonstrates that there are no solvent molecules and C-H oscillators existing in the inner coordination sphere of Yb3+, which is conducive to alleviating the quenching effect. Meanwhile, we also carried out experiments to verify that it was thermodynamically feasible for ligands to sensitize the luminescence of center ion through internal redox processes. Moreover, several groups of near-infrared organic light-emitting diodes based on [Yb(DTFM-DPyPDA)2](DIEA) were fabricated based on the solution-processing method, and the highest irradiance of 110,284 μW/m2 was realized by optimizing the device structure.

Metal Complexes with Schiff Bases: Data Collection and Recent Studies on Biological Activities

Metal complexes play a crucial role in pharmaceutical sciences owing to their wide and significant activities. Schiff bases (SBs) are multifaceted pharmacophores capable of forming chelating complexes with various metals in different oxidation states. Complexes with SBs are extensively studied for their numerous advantages, including low cost and simple synthetic strategies. They have been reported to possess a variety of biological activities, including antimicrobial, anticancer, antioxidant, antimalarial, analgesic, antiviral, antipyretic, and antidiabetic ones. This review summarizes the most recent studies on the antimicrobial and antiproliferative activities of SBs-metal complexes. Moreover, recent studies regarding mononuclear and binuclear complexes with SBs are described, including antioxidant, antidiabetic, antimalarial, antileishmanial, anti-Alzheimer, and catecholase activities.