catena-Poly[[[diaqua-bis(8-hydroxy-quinoline N-oxide-κO)cobalt(II)]-µ-2,5-dimethyl-pyrazine 1,4-dioxide-κO:O] bis-(perchlorate)].

In the title complex, {[Co(C(6)H(8)N(2)O(2))(C(9)H(7)NO(2))(H(2)O)(2)](ClO(4))(2)}(n), the Co(II) ion lies on an inversion centre and is coordinated in a slightly distorted octa-hedral environment. The 2,5-dimethyl-pyrazine 1,4-dioxide ligand, which also lies on an inversion center, acts as a bridging ligand, linking symmetry-related Co(II) ions [Co⋯Co = 8.669 (3) Å] and forming one-dimensional chains along the b axis. In the crystal structure, these chains are linked by inter-molecular aqua-perchlorate O-H⋯O hydrogen bonds, forming two-dimensional layers which are in turn connected into a three-dimensional network via π-π stacking inter-actions between quinoline rings, with a centroid-centroid distance of 3.580 (3) Å. An intermolecular O-H⋯Cl inter-action is also present.