A hydrated ethyl­ene­di­ammonium salt of a new polymeric polyoxoanion: (H2en)4[Co(H2O)2(OH)2(VO)6(HPO4)4(PO4)4]·3H2O

The title compound, tetrakis­(ethyl­enedi­ammonium) tetra‐μ‐hydrogenphosphato‐di‐μ‐hydro­xo‐ tetra‐μ‐phosphato‐bis­(aqua­cobalt)­hexakis­(oxovanadium) trihydrate, was synthesized hydro­thermally at moderate temperature. The structure consists of diprotonated ethyl­enedi­ammonium cations and layers of the polyanions. The polyanion contains four PO₄ tetrahedra and three VO₅ square pyramids that are linked through corner‐sharing by alternating P—O—V, which gives rise to a chain. The chains, connected by CoO₄(H₂O)₂ octahedra, form layers, resulting in a two‐dimensional layered structure. The Co—O distances are in the range 1.984 (3)–2.038 (4) Å, the P—O distances 1.508 (3)–1.575 (3) Å and the V—O distances 1.585 (3)–2.010 (3) Å.