Linear 3d–4f compounds: synthesis, structure, and determination of the d–f magnetic interaction

Abstract

A family of [RE₂M₂L₂(BA)₆] (RE = Gd, Tb, Dy, Y; M = Co, Ni, Cu, Zn; L = 1,2-bis(2-hydroxy-3-methoxybenzylidene)hydrazine; BA = benzoic acid) complexes were synthesized and structurally and magnetically characterized. The magnetic interactions between spin centers were systematically investigated. The interactions of M–M (M = Co, Ni and Cu) and Gd–Ni/Cu were extracted from the fitting of the experimental data of Y₂M₂ (M = Co, Ni and Cu) and Gd₂M₂ (M = Ni and Cu) derivatives, respectively. Furthermore, the Ln–M interactions were qualitatively analyzed by deducting the M–M coupling and the contribution of the crystal-field effects of the Ln^III ion from the total magnetic susceptibility of Ln₂M₂ (Ln = Dy and Tb) compounds. In addition, complex [Dy₂Zn₂L₂(BA)₆] shows field induced single molecular magnet behavior profiting from the isolated anisotropic dysprosium ions.