Bis(ethyl-enedi-ammonium) μ-ethyl-enedi-aminetetra-acetato-1κ3 O,N,O':2κ3 O'',N',O'''-bis-[tri-oxidomolybdate(VI)] tetra-hydrate.

The title compound, (C2H10N2)2[(C10H12N2O8)(MoO3)2]·4H2O, which crystallizes in the monoclinic C2/c space group, was obtained by mixing molybdenum oxide, ethyl-enedi-amine and ethyl-enedi-amine-tetra-acetic acid (H4edta) in a 2:4:1 ratio. The complex anion contains two MoO3 units bridged by an edta4- anion. The midpoint of the central C-C bond of the edta4- anion is located on a crystallographic inversion centre. The independent Mo atom is tridentately coordin-ated by a nitro-gen atom and two carboxyl-ate groups of the edta4- ligand, together with the three oxo ligands, producing a distorted octa-hedral coordination environment. In the three-dimensional supra-molecular crystal structure, the dinuclear anions, the organo-ammonium counter-ions and the solvent water mol-ecules are linked by N-H⋯Ow, N-H⋯Oedta and O-H⋯O hydrogen bonds.