Aqua­(2,9-dimethyl-1,10-phenanthroline-κ(2) N,N′)(formato-κ(2) O,O′)(formato-κO)cobalt(II) monohydrate

The asymmetric unit of the title compound, [Co(HCO(2))(2)(C(14)H(12)N(2))(H(2)O)]·H(2)O, contains a mononuclear complex mol­ecule hydrogen bonded to a lattice water mol­ecule. The Co(II) cation is in a distorted octa­hedral coordination environment defined by the two N atoms of the 2,9-dimethyl-1,10-phenanthroline ligand and four O atoms. Two of these are from a chelating formate anion, one from a monodentate formate and the last from an aqua ligand. In the crystal, mol­ecules are connected by O—H⋯O hydrogen bonds, forming double chains along [100] with the 2,9-dimethyl-1,10-phenanthroline ligands pointing outwards from each chain. These chains are further linked into layers parallel to (011) by inter-chain π–π stacking inter­actions with centroid–centroid distances of 3.61 (1) Å.