Strong intramolecular DyIII–DyIII magnetic couplings up to 15.00 cm−1 in phenoxyl-bridged dinuclear 4f complexes

Abstract

Three phenoxyl-bridged dinuclear lanthanide complexes [Ln₂(dbm)₂(LH₂)₂]·H₂O (Ln = Gd for 1, Tb for 2, and Dy for 3, LH₃ = (1E,3E)-2-hydroxy-5-methylisophthalaldehyde dioxime, Hdbm = dibenzoylmethane) were synthesized, and structurally and magnetically characterized. In these complexes, Ln^III ions are eight coordinated and lie in D_4d local symmetry. Intramolecular ferromagnetic couplings are exhibited between Ln^III ions. Surprisingly, the intramolecular Dy^III–Dy^III magnetic couplings are up to 15.00 cm⁻¹, which are the strongest ones of the reported Dy₂ complexes by phenoxyl bridges. Complex 3 shows single-molecule magnet behavior with an effective energy of 76.18 K under zero dc field which is in accordance with the calculated value. The magnetostructural correlation of phenoxyl-bridged Dy₂ complexes is analyzed.