trans-diaquabis(pyridine-4-carboxylato)cobalt(II) dihydrate

By the hydrothermal method, a four-coordinate monomeric Co-II complex with two isonicotinate (C6H4NO2) ligands, [Co(L)(2)(H2O)(2)].2H(2)O, where HL Is isonicotinic acid, has been synthesized; It has been characterized by elemental analysis and X-ray diffraction techniques. The crystal structure reveals that the Co-II atom, on an inversion center, has a CoN2O2 square-planar primary coordination environment and weak axial interactions with two more water molecules. Isonicotinate is bonded through nitrogen. A striking structural feature is the formation of a three-dimensional supramolecular architecture through intermolecular O-H...O hydrogen bonds.