Polyoxometalate tri-supported transition metal complexes containing mixed-valent transition metal ions

Three compounds, [AsMo₈V₆O₄₂][Cu(2,2’-bpy)₂]₂[Cu(2,2’-bpy)]·4H₂O (1), [PMo₈V₆O₄₂][Cu(2,2’-bpy)₂]₂[Cu(2,2’-bpy)]·3H₂O (2) and [PMo₈V₆O₄₂][Cu(2,2’-bpy)₂]₂[Cu(2,2’-bpy)]·3.5H₂O (3), have been synthesized under hydrothermal conditions and characterized by IR, UV-Vis, XRD, TG, elemental analysis and X-ray diffraction analysis. Single-crystal X-ray structure analysis reveals that 1 and 2 are isostructural and isomorphous, whereas 2 and 3 are polymorphs. Polymorphs of 1 have not been synthesized yet. The mixed-valent transition metal ion in 1-3 have been further confirmed by TG analyses. Catalytic properties of 1 and 2 have also been studied.