Crystal structure of tetra­aqua­bis(3,5-di­amino-4H-1,2,4-triazol-1-ium)cobalt(II) bis­[bis­(pyridine-2,6-di­carboxyl­ato)cobaltate(II)] dihydrate

The asymmetric unit of the title compound, [Co(C(2)H(6)N(5))(2)(H(2)O)(4)][Co(C(7)H(3)NO(4))(2)](2)·2H(2)O, features 1.5 Co(II) ions (one anionic complex and one half cationic complex) and one water mol­ecule. In the cationic complex, the Co(II) atom is located on an inversion centre and is coordinated by two triazolium cations and four water mol­ecules, adopting an octa­hedral geometry where the N atoms of the two triazolium cations occupy the axial positions and the O atoms of the four water mol­ecules the equatorial positions. The two triazole ligands are parallel offset (with a distance of 1.38 Å between their planes). In the anionic complex, the Co(II) ion is six-coordinated by two N and four O atoms of the two pyridine-2,6-di­carboxyl­ate anions, exhibiting a slightly distorted octa­hedral coordination geometry in which the mean plane of the two pyridine-2,6-di­carboxyl­ate anions are almost perpendicular to each other, making a dihedral angle of 85.87 (2)°. In the crystal, mol­ecules are linked into a three-dimensional network via C—H⋯O, C—H⋯N, O—H⋯O and N—H⋯O hydrogen bonds.