Strong intramolecular Dy-III-Dy-III magnetic couplings up to 15.00 cm(-1) in phenoxyl-bridged dinuclear 4f complexes

Three phenoxyl-bridged dinuclear lanthanide complexes [Ln(2)(dbm)(2)(LH2)(2)]center dot 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 Dy-2 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 Dy-2 complexes is analyzed.