Abstract: | The Reaction of freshly precipitated NiCO3 with phenanthroline and suberic acid in CH3OH/H2O at room temperature gave the title complex consisting of polymeric {NiNi(phen)(H2O)4]2L4/2}2+ cationic chains, suberate anions and hydrogen bonded H2O molecules. The cationic chains are generated from bis‐monodentate suberato ligands bridging the trinuclear {NiNi(phen)(H2O)4]2}6+ groups, in which the central Ni atom is, via two μ‐H2O molecules, coordinated to two monodentate cationic Ni(phen)(H2O)4]2+ complex ligands at trans positions. The NiO6 octahedral coordination about the central Ni atom is elongated tetragonally distorted with d(Ni—O) = 2.033—2.166Å and the NiN2O4 octahedra about the side Ni atoms are significantly distorted with d(Ni—N) = 2.089, 2.099Å, d(Ni—O) = 2.046—2.117Å. The polymeric cationic chains are assembled via π—π stacking interactions into open 2D layers, between which the suberate anions and crystal H2O molecules are sandwiched. Crystal data: triclinic, P1¯ (no. 2), a = 11.397(2)Å, b = 11.975(2)Å, c = 12.500(2)Å, α = 107.75(1)°, β = 104.50(1)°, γ = 109.68(1)°, Z = 1, R = 0.0521, wR2 = 0.1249 for 3892 out of 6198 reflections with Fo2 > 2σ(Fo2). |