A Co-monosubstituted Keggin polyoxometalate with an antenna ligand and three cobalt(II) chains as counterion

A Co-monosubstituted Keggin polyoxometalate with an antenna ligand linked to the Co(II) center with a Co(II)-containing cation has been prepared. The title compound, formulated as {Co(H2O)4(4,4′-bpy)}2(4,4′-Hbpy)2[SiW11Co(4,4′-bpy)O39] · 5H2O (1) (4,4′-bpy = 4,4′-bipyridine), was synthesized and characterized by elemental analysis, IR spectra, TG analysis, X-ray single crystal structure analysis and magnetic measurements. As far as we know, the title compound represents the first Co(II) substituted Keggin polyoxometalate with an antenna ligand structurally and magnetically characterized.