catena-Poly[[tetraaquanickel(II)]-μ(3)-benzene-1,3,5-tricarboxylato-3′:1:2-κ(4) O (1):O (3),O (3′):O (5)-[tetraaquanickel(II)]-μ(2)-benzene-1,3,5-tricarboxylato-2:3κ(2) O (1):O (3)-[tetraaquanickel(II)]]

The microwave solvothermal reaction of nickel nitrate with trimesic acid provided the title compound, [Ni(3)(BTC)(2)(H(2)O)(12)](n) (BTC = benzene-1,3,5-tricarboxyl­ate anion, C(9)H(3)O(6)), which is a metal coordination polymer composed of one-dimensional zigzag chains. The crystal under investigation was ramecically twinned with an approximate twin domain ratio of 1:1. In the asymmetric unit, there are two types of Ni atoms. One of the NiO(6) groups (2 symmetry) is coordinated to only one carboxyl­ate group and thus terminal, the other is bridging, forming the coordination polymer. The extended chains are connected by the organic BTC anions via μ (2)-linkages. O—H⋯O hydrogen bonds and π–π inter­actions between the chains [centroid–centroid distance 3.58 (1) Å] induce the complex to mimic a three-dimensional structure.