catena-Poly[[[trans-diaqua­bis(pyridine-κN)cobalt(II)]-μ-(4-{N′-[1-(3-acetyl-4-methyl-1H-pyrazol-5-yl)ethyl­idene]hydrazino}benzoato-κ(3) O:N,N′)-[bis­(pyridine-κN)cobalt(III)]-μ-(4-{N′-[1-(3-acetyl-4-methyl-1H-pyrazol-5-yl)ethyl­idene]hydrazino}benzoato-κ(3) N,N′:O)]perchlorate 3.66-hydrate]

The title compound, {[Co(2)(C(15)H(14)N(4)O(3))(2)(C(5)H(5)N)(4)(H(2)O)(2)]ClO(4)·3.66H(2)O}(n), is a one-dimensional coordination polymer, with both Co(II) and Co(III) centres in its structure. The ligand environment surrounding Co(III) is formed by two N,N-chelating pyrazole-containing ligands and two pyridine mol­ecules in axial positions. The high-spin Co(II) ions, situated at crystallographic centres of inversion, exhibit a distorted octa­hedral coordination mode. The ClO(4) (−) anion is linked to the polymer chain via hydrogen bonds. The chains are connected by hydrogen bonds to produce a three-dimensional structure.