Hydro-thermal synthesis and extended structure of poly[aqua-(μ _5--ethylene-diaminetetraacetato)dizinc(II)]

In the extended structure of the title compound,[Zn₂(C ₁₀H₁₂N₂O₈)(H₂O)], prepared under hydro-thermal conditions, there are two distinct Zn^II sites. The first, with octa-hedral geometry, bonds to two N and three O atoms from one ethyl-ene-diamine-tetra-acetate tetraanion (EDTA) and one water molecule. The second, with tetra-hedral geometry, coordinates to O atoms from four different EDTA ligands. The EDTA ligand almost encapsulates the octa-hedral Zn^II ion and binds to four symmetry-related tetra-hedral Zn ^II ions, hence generating the extended structure. One noncoordinated O-atom site on the EDTA ligand connects to the water mol-ecule by hydrogen bonding. Structural comparisons are made with other compounds containing zinc, EDTA and water.