Modulating single-molecule magnet behaviour of phenoxo-O bridged lanthanide(iii) dinuclear complexes by using different β-diketonate coligands

Abstract

Three dinuclear Dy(III) complexes, [Dy₂(tfa)₄L₂] (1), [Dy₂(TTA)₄L₂] (2) and [Dy₂(dbm)₄L₂·2CH₃CN·0.5H₂O] (3) (tfa = trifluoroacetylacetonate, TTA = 2-thenoyltrifluoroacetone, dbm = dibenzoylmethane and HL = 2-[((4-bromophenyl)-imino)methyl]-8-hydroxyquinoline, have been synthesized, and structurally and magnetically characterized. The Dy(III) ions are eight-coordinated with two bidentate β-diketonate and two μ₂-O bridging 8-hydroxyquinoline Schiff base ligands. Magnetic studies reveal that 1–3 exhibit different magnetic relaxation behaviors with the anisotropic barriers of 9.61 K (1), 54.81 K (2) and 30.98 K (3), respectively. The different magnetic relaxation behaviors of the three Dy₂ complexes originate from the different chemical environments of the central Dy³⁺ ions with different β-diketonate coligands.