Synthesis and photoluminescent properties of four novel trinuclear europium complexes based on two tris-β-diketones ligands

Four novel trinuclear europium complexes with two tris-β-diketones ligands have been synthesized, and the chemical structures of ligands and complexes were characterized by FT-IR, UV–vis, 1H NMR, 13C NMR, XRD, ESI-MS, and element analysis. The potoluminescent properties of trinuclear complexes in solid and THF solution were investigated. All trinuclear complexes exhibited strong relative luminescent intensity and long luminescent lifetime. Meanwhile, the results of lifetime decay curves indicated that only one chemical environment existed around the europium ion. The intrinsic luminescent quantum yields (ΦLN) and experimental intensity parameters of trinuclear complexes were obtained based on the emission spectra and luminescent lifetime of 5D0 excited state for europium ion. All trinuclear europium complexes exhibited relative high intrinsic luminescent yield and intensity parameters. Especially, due to the contribution of addition two europium lumophors in trinuclear europium complexes, the trinuclear complexes containing TTA exhibited much longer lifetime and higher intrinsic quantum yield than mononuclear europium complex Eu(TTA)3phen.

Four novel trinuclear europium complexes based on two tris-β-diketones ligands were designed and synthesized. All trinuclear europium complexes exhibited excellent luminescent properties and good thermal stability. Especially, due to the contribution of addition two europium ions lumophors in trinuclear europium complexes, the complexes containing TTA ligands exhibited much longer lifetime and higher quantum yield than mononuclear europium complex Eu(TTA)3phen.Figure optionsDownload as PowerPoint slideHighlights
► Four novel trinuclear europium complexes were designed and synthesized.
► All trinuclear complexes exhibited high luminescent properties.
► Some trinuclear complexes showed much longer lifetime than mononuclear complex.
► These complexes with TTA showed higher quantum yield than mononuclear complex.