Trans-Tetra­Aqua­Bis­(Isonicotinamide-Κn 1)Cobalt(Ii) Bis­(3-Hy­Droxy­Benzoate) Tetra­Hydrate

The asymmetric unit of the title compound, [Co(C6H6N2O)2(H2O)4](C7H5O3)2·4H2O, contains one-half of the complex cation with the CoII ion located on an inversion center, a 3-hy­droxy­benzoate counter-anion and two uncoordinated water mol­ecules. Four water O atoms in the equatorial plane around the CoII 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 carboxyl­ate 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 inter­actions between the benzene and pyridine rings, with centroid–centroid distances of 3.458 (1) and 3.606 (1) Å, respectively.PubMedScopu