Tetra­aqua­bis(2-methyl­benzimidazolium-1,3-diacetato-κO)zinc(II) tetra­hydrate

The asymmetric unit of the title compound, [Zn(C(12)H(11)N(2)O(4))(2)(H(2)O)(4)]·4H(2)O, contains one-half of the complex mol­ecule and two uncoordin­ated water mol­ecules. The four water O atoms in the equatorial plane around the Zn(II) centre ([Image: see text] symmetry) form a distorted square-planar arrangement, while the distorted octa­hedral coordination geometry is completed by the O atoms of the zwitterionic 2-methyl­benzimidazolium-1,3-diacetate ligands in the axial positions. The benzimidazole ring system is planar, with a maximum deviation of 0.041 (3) Å. Intra­molecular O—H⋯O hydrogen bonding results in the formation of a non-planar six-membered ring. In the crystal structure, strong intra- and inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network. π–π contacts between benzimidazole rings [centroid–centroid distance = 3.899 (1) Å] may further stabilize the structure.