Poly[octa-μ-aqua-tetra-aqua-bis(μ(4)-5-sulfonatobenzene-1,3-dicarboxyl-ato)nickel(II)tetra-sodium].

In the crystal structure of the title compound, [Na(4)Ni(C(8)H(3)O(7)S)(2)(H(2)O)(12)](n), the Ni(II) cation occupies an inversion centre and is coordinated by the carboxyl groups of the sulfoisophthalate trianions and water mol-ecules in a distorted octa-hedral geometry. Two independent Na(I) atoms are connected by the carboxyl and sulfonate groups of the sulfoisophthalate ligands anions and water mol-ecules in a distorted octa-hedral geometry. The sulfoisophthalate ligands and coordinated water mol-ecules bridge the Ni(II) and Na(I) cations, forming a three-dimensional polymeric structure. Weak π-π stacking is present between parallel benzene rings [centroid-centroid distance = 3.9349†(10)†à ]. Extensive O-H⋯O and C-H⋯O hydrogen bonding helps to stabilize the crystal structure.