trans-Di­aqua­bis­(pyridazine-3-carboxyl­ato-κ2 N 2,O)cobalt(II) dihydrate

The title compound, [Co(C 5 H 3 N 2 O 2 ) 2 (H 2 O) 2 ]·2H 2 O, contains a Co II ion on an inversion center, exhibiting an octa­hedral coordination geometry. The equatorial plane is formed by two trans -related N , O -bidentate pyridazine-3-carboxyl­ate ligands and the axial positions are occupied by two water mol­ecules. The Co II complex mol­ecules are stacked in a column along the a- axis direction by an O—H⋯N hydrogen bond between the non-coordinating pyridazine N atom and the coordinating water mol­ecule. These columns are further connected into a layer parallel to the ac plane by additional hydrogen bonds involving the coordinating and non-coordinating water mol­ecules, and the non-coordinating carboxyl­ate O atom. The crystal packing is completed by inter­layer weak C—H⋯O inter­actions.