Hexameric polyoxometalates decorated by six 3d–4f heterometallic clusters

Abstract

Two nanosized hexameric polyoxometalate-based solid state assemblies (H₂en)₆Na₁₅K₉[Dy₆Fe₆(H₂O)₁₂(SiW₁₀O₃₈)₆]·34H₂O (1) and K₁₃Na₁₇[H₂en]₃[Tb₆Fe₆(H₂O)₁₂(SiW₁₀O₃₈)₆]·40H₂O (2) (en = 1,2-ethylenediamine), decorated by six [Ln-(μ₃-O)₃-Fe] 3d–4f heterometallic clusters, have been synthesized by the hydrothermal method, and characterized by IR, element analysis, magnetic studies and the single-crystal X-ray analyses. The detailed study of the synthetic conditions reveals that the use of the organic ligands, pH value and the reaction temperature all play important roles in the synthesis of the 3d–4f heterometallic POMs. Magnetic study suggests the presence of antiferromagnetic interactions in these two compounds.