Crystal structure of di­aqua­(μ(2)-tri­ethyl­ene­tetra­minehexa­acetato)­dizinc tetra­hydrate

The reaction of ZnO and tri­ethyl­ene­tetra­minehexaacetic acid (H(6)TTHA) in aqueous solution after refluxing yields the binuclear title compound, [Zn(2)(C(18)H(26)N(4)O(12))(H(2)O)(2)]·4H(2)O. There is a centre of symmetry in the [Zn(2)(H(2)TTHA)(H(2)O)(2)] mol­ecule in the crystalline state. Both Zn(II) ions are octahedrally surrounded and bound by an N(2)O(3) donor set from the H(2)TTHA(4−) anion and a water mol­ecule; the N atoms are cis and the water mol­ecule is trans to an N atom. The Zn⋯Zn separation is 7.562 (1) Å. An intra­molecular C—H⋯O inter­action is observed and both carboxyl­ate H atoms are disordered over two adjacent sites. In the crystal, the components are linked by O—H⋯O and C—H⋯O hydrogen bonds generating a three-dimensonal network.