trans-diaquabis(nicotinamide-N′-)bis(4-nitrobenzoato-O)cobalt(II)

The title cobalt complex, [Co(C7H4NO4)(2)(C6H6N2O)(2)(H2O)(2)], is monomeric and centrosymmetric, and contains two water molecules, two 4-nitrobenzoate and two nicotinamide (NA) ligands, all acting as monodentate ligands. The four nearest O atoms around the Co atom form a slightly distorted square-planar arrangement, with a distorted octahedral coordination completed by the pyridine N atoms of the NA ligand, at a distance of 2.134 (2) Angstrom. The water molecules are hydrogen bonded to the carboxyl O atoms [O ... O 2.634(5) Angstrom].