A cobalt-containing pseudosandwich-type polyoxometalate based on a lacunary Lindqvist polyoxovanadate

Abstract

A novel pseudosandwich-type polyoxovanadate, Co^II₂{(VO₂)Co^III(Co^IIIL)₂[V₅O₁₆]₂}·23H₂O (1) (L = 1,3-propanediamine, 1,3-pda), has been isolated using a conventional aqueous solution method and characterized by elemental analysis, IR spectrum, thermal gravimetric analysis and magnetism. Single crystal X-ray diffraction analyses indicate that polyoxoanion 1 is composed of a {Co^III₃(1,3-pda)₂} cluster coordinated by two lacunary Lindqvist polyoxovanadates [V₅O₁₈]. Polyoxoanion 1 contains three Co^III centers in its central metal set, which was first observed in the polyoxometalate chemistry. Further, two Co^III ions in polyoxoanion 1 are functionalized by two 1,3-pda ligands resulting in a pseudosandwich-type polyoxovanadate-based organic–inorganic hybrid material, which represents the first pseudosandwich-type polyoxovanadate decorated by two 1,3-pda ligands.