Poly[μ(2)-aqua-diaqua­(μ(8)-3-nitro­benzene-1,2-dicarboxylato)(μ(6)-3-nitro­benzene-1,2-dicarboxylato)tetra­sodium]

In the title layered coordination polymer, [Na(4)(C(8)H(3)NO(6))(2)(H(2)O)(3)](n), the doubly deprotonated 3-nitro­benzene-1,2-dicarboxyl­ate ligands exhibit μ(8)- and μ(6)-coordination modes to the sodium ions, generating sheets lying parallel to (001). The coordination environments of the sodium ions are distorted octa­hedral, distorted trigonal-bipyramidal and moncapped trigonal-prismatic. One of the nitro groups is disordered over two sets of sites with site-occupancy factors 0.580 (8):0.419 (2). A network of O—H⋯O and O—H⋯N hydrogen bonds helps to establish the packing.