New dinuclear compounds of dysprosium and erbium constructed by an O-vanillin ligand and β-diketonate coligand: Synthesis, near-Infrared luminescent and magnetism

Abstract

Four novel lanthanide complexes based on O-vanillin (HL) ligand and 1,3-diphenyl-1,3-propanedione (Hdbm) coligand have been assembled by utilizing different solvents: [Dy2(dbm)4(L)2]·CH3CN (1), [Dy2(dbm)4(L)2]·0.25C2H5OH·0.5CH2Cl2 (2), [Er2(dbm)4(L)2] (3), [Er2(dbm)4(L)2]·1.25CH2Cl2 (4). Meanwhile, their crystal structures are confirmed by single crystal X-ray diffraction analysis. The near-infrared luminescent studies indicate that 3 and 4 emit the emission peaks of the corresponding Er3+ ions, which are located in the third window of optical communication. The magnetic studies reveal that the DyIII complexes exhibit single-molecule-magnet behavior and effective energy barriers for the reversal of magnetization varying from Ueff = 115.34 K for complex 1 to Ueff = 170.96 K for complex 2, indicating the tuning effect of solvent molecules on slow magnetic relaxation.