A series of mononuclear lanthanide complexes constructed by Schiff base and β-diketonate ligands: synthesis, structures, magnetic and fluorescent properties

Abstract

The Schiff base H2bcsdt (H2bcsdt = N1,N3-bis(5-chlorosalicyladehyde) diethylenetriamine) and the β-diketonate Hdbm (Hdbm = dibenzoylmethane) have been employed as a ligand and a pro-ligand to construct a series of Ln(III) complexes. Five mononuclear compounds were synthesized under solvothermal conditions. Single-crystal X-ray diffraction analyses reveal that they are formulated as [Ln(bcsdt)(dbm)(H2O)]·MeCN (Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5)). The metal ions in complexes 1–5 are all eight-coordinated and display a similar capped triangular dodecahedron (D2h) geometry. The fluorescent and magnetic properties of 1–5 were investigated. Complex 2 exhibits an intense green luminescence emission which is characteristic of the Tb(III) ion. Weak intermolecular antiferromagnetic interactions were determined in 2–5.