New dinuclear lanthanide complexes derived from Schiff base ligand and β-diketonate co-ligand: Synthesis, crystal structures, luminescent and magnetic properties

Six new rare earth metal complexes with the general formula [RE2(HL)2(dbm)2(CH3OH)2].2CH3OH (RE = Y (1), Tb (2), Dy (3), Ho (4), Er (5), Yb (6)) have been synthesized and constructed by Schiff base ligand and β-diketonate co-ligand. The single crystal X-ray structure study shows that 1–6 are phenoxo-O-bridged centrosymmetric dinuclear complexes and crystallize in the monoclinic P21/n space group. The near-infrared luminescent study indicates that complex 5 and 6 exhibit the characteristic emission peaks of the Er (III) and Yb (III) ions. Significantly, the emission peak of complex 5 at 1530 nm is located in the third telecommunication window of telecommunication, suggesting complex 5 has great potential application in modern telecommunication network. The alternating-current magnetic analysis reveals that the dysprosium complex exhibits single-molecule-magnet behavior under an applied dc field of 3000 Oe. In addition, the effective energy barrier of 3 is 12.45 K and pre-exponential factor is 1.08 × 10−6 s.