Poly[di-μ(9)-citrato-tetra­sodiumzinc]

In the title compound, [Na(4)Zn(C(6)H(5)O(7))(2)](n), the Zn(II) ion lies on an inversion center and is coordinated by six O atoms from two citrate ligands, forming a distorted octa­hedral geometry. There are two crystallographically independent Na(+) cations in the asymmetric unit. One Na(+) cation exhibits a distorted square-pyramidal geometry defined by five O atoms from four citrate ligands. The other Na(+) cation is surrounded by six O atoms from five citrate ligands in a distorted octa­hedral geometry. The Na(+) cations are bridged by citrate carboxyl­ate groups, forming a layer parallel to (100). The layers are further assembled into a three-dimensional network with the [Zn(citrate)(2)](4−) building units as ‘pillars’; O—H⋯O hydrogen bonds also stabilize the structure.