Hydrothermal synthesis and crystal structural characterization of two new modified polyoxometalates constructed of positive and negative metal-oxo cluster ions

Two new interesting polyoxometalate derivatives {[Ni(2,2′‐bipy)2H2O]2[Mo3VMo5VIV8IVO40(PO4)]}{[Ni(2,2′‐bipy)2H2O]2[Mo3VMo5VIV8IVO40(PO4)]}·5H2O1 and {[Co(2,2′‐bipy)2H2O]4[Mo4VMo4VIV8IVO40(PO4)]}{[Co(2,2′‐bipy)2H2O]2[Mo3VMo5VIV8IVO40(PO4)]}(H3O)·4H2O2 constructed of modified metal-oxo cluster ions carrying positive and negative changes, respectively, was hydrothermally prepared and structurally characterized by IR, ESR, XPS, elemental analysis and X-ray crystallography. The result of structure determination shows that compound 1 and 2 are isostructural and both contain polyoxocation and polyoxoanion, and both cation and anion are built on mixed Mo-V tetra-capped pseudo-Keggin units with P centre, [Mo8V8O40(PO4)]n−, bonded to four or two [Ni(2,2′-bipy)2H2O]2+ complexes, respectively, via terminal oxygen of the capping V atoms. Magnetism measurement indicates that there exists antiferromagnetic interaction in complex 1 and 2.