Efficient and tunable multi-color and white light Ln-MOFs with high luminescence quantum yields

Abstract

A series of isomorphic Ln-MOFs, formulated as [Ln₂(m-BDC)₃(Phen)₂]·(DMF) (Ln = Eu 1, Gd 2, Tb 3, Ln = mixed-lanthanide 4–9, m-H₂BDC = 1,3-benzenedicarboxylic acid, Phen = 1,10-phenanthroline) have been solvothermally synthesized. Single-crystal X-ray diffraction studies reveal that the isostructural compounds are constructed by two types of dinuclear SBUs, {Ln(COO)₅(Phen)}₂ and {Ln(COO)₄(Phen)}₂, which are six-connected by m-BDC²⁻ ligands to generate a 3D pcu topological net. Precisely tuning the stoichiometry of the lanthanide ions in the frameworks leads to the synthesis of high-efficiency multi-color and white light luminescent materials. Moreover, the quantum yields of these materials range from 13 to 75% and the white-light emission quantum yield can reach up to 32%.