trans-Tetra­aqua­bis­(isonicotinamide-κN 1)cobalt(II) bis­(3-hy­droxy­benzoate) tetra­hydrate

The asymmetric unit of the title compound, [Co(C(6)H(6)N(2)O)(2)(H(2)O)(4)](C(7)H(5)O(3))(2)·4H(2)O, contains one-half of the complex cation with the Co(II) ion located on an inversion center, a 3-hy-droxy-benzoate counter-anion and two uncoordinated water mol-ecules. Four water O atoms in the equatorial plane around the Co(II) ion [Co-O = 2.0593 (16) and 2.1118 (16) Å] form a slightly distorted square-planar arrangement, and the distorted octahedral geometry is completed by the two N atoms [Co-N = 2.1306 (18) Å] from two isonicotinamide ligands. In the anion, the carboxyl-ate group is twisted from the attached benzene ring at 8.84 (17)°. In the crystal, a three-dimensional hydrogen-bonding network, formed by classical O-H⋯O and N-H⋯O hydrogen bonds, consolidates the crystal packing, which exhibits π-π inter-actions between the benzene and pyridine rings, with centroid-centroid distances of 3.458 (1) and 3.606 (1) Å, respectively.