Slow Magnetic Relaxation Behavior in Rare Ln–Cu–Ln Linear Trinuclear Complexes

Abstract

AbstractThree novel heterotrinuclear complexes {[Ln(hfac)3]2CuL2} [LnIII = Gd (1), Tb (2), and Dy (3); HL = 4‐methoxysalicylaldehyde, hfac = hexafluoroacetylacetone] have been synthesized and characterized by X‐ray crystallography as well as by a study of their magnetic properties. In these compounds, CuII and LnIII ions are bridged by two phenolato and aldehyde oxygen atoms from two 4‐methoxysalicylaldehyde ligands and one oxygen atom from one hfac ligand, resulting in a linear trinuclear core of Ln–Cu–Ln with one central CuII ion and two terminal LnIII ions. Furthermore, the linear trinuclear units generate a pseudo‐one‐dimensional chain through π–π interactions. Direct‐current magnetic susceptibility studies show that there is a ferromagnetic interaction between CuII and GdIII ions. Tb and Dy complexes exhibit frequency‐dependent out‐of‐phase signals, indicating slow magnetic relaxation behavior.