A hydrated ethylenediammonium salt of a new polymeric polyoxoanion: (H(2)en)(4)[Co(H2O)(2)(OH)(2)(VO)(6)(HPO4)(4)(PO4)(4)]center dot 3H(2)O

The title compound, tetrakis(ethylenediammonium) tetra-mu-hydrogenphosphato -di-mu-hydroxo- tetra-mu-phosphato-bis(aquacobalt)hexakis(oxovanadium) trih ydrate, was synthesized hydrothermally at moderate temperature. The structu re consists of diprotonated ethylenediammonium cations and layers of the po lyanions. The polyanion contains four PO4 tetrahedra and three VO5 square p yramids 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, fo rm layers, resulting in a two-dimensional layered structure. The Co-O dista nces are in the range 1.984 (3)- 2.038 (4) Angstrom, the P-O distances 1.50 8 (3)-1.575 (3) Angstrom and the V-O distances 1.585 (3)-2.010 (3) Angstrom .