Controllable syntheses and magnetic properties of novel homoleptic triple-decker lanthanide complexes.

Four novel homoleptic triple-decker lanthanide complexes, [Ln(L)(Cl-salphen)]·0.5ClCHCHCl (Ln = Gd (1), Ho (2), Tb (3), and Dy (4)), have been designed and synthesized based on a Schiff base ligand N,N'-bis(5-chlorosalicylidene)-o-phenylenediamine (Cl-salphenH) and the building blocks [(acac)Ln(L)]; these complexes were derived from a closed-macrocyclic ligand (HL) obtained by the [2 + 2] template condensation of 2,6-diformyl-4-methylphenol and 1,3-diaminopropane in the presence of lanthanide acetylacetonates. Single-crystal X-ray analyses show that central Ln ions adopt distorted square antiprism conformations with D symmetry. Theoretical analysis and magnetic measurements reveal that Dy complex 4 behaves as a typical SMM with the characteristics of slow magnetic relaxation behavior and intermetallic ferromagnetic interaction.