Crystal structure of trans-di­aqua­bis­­(nicotinamide-κN1)bis­­(4-nitro­benzoato-κO)manganese(II)

The asymmetric unit of the title compound, [Mn(C7H4NO4)2(C6H6N2O)2(H2O)2], contains one MnII atom, one 4-nitro­benzoate (NB) anion, one nicotinamide (NA) ligand and one water mol­ecule; NA and NB each act as a monodentate ligand. The MnII atom, lying on an inversion centre, is coordinated by four O atoms and two pyridine N atoms in a distorted octa­hedral geometry. The water mol­ecules are hydrogen bonded to the carboxyl­ate O atoms. The dihedral angle between the carboxyl­ate group and the adjacent benzene ring is 24.4 (3)°, while the benzene and pyridine rings are oriented at a dihedral angle of 86.63 (11)°. In the crystal, O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules, forming a layer parallel to the ab plane. The layers are further linked via weak C—H⋯O hydrogen bonds, a π–π stacking inter­action [centroid–centroid distance = 3.868 (2) Å] and a weak C—H⋯π inter­action, resulting in a three-dimensional network.