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

The title compound, (CHN)[(CHNO)(MoO)]·4HO, which crystallizes in the monoclinic 2/ space group, was obtained by mixing molybdenum oxide, ethyl-enedi-amine and ethyl-enedi-amine-tetra-acetic acid (Hedta) in a 2:4:1 ratio. The complex anion contains two MoO units bridged by an edta anion. The midpoint of the central C-C bond of the edta 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 edta 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⋯O, N-H⋯O and O-H⋯O hydrogen bonds.