Poly[[tetra­aquatetrakis­[μ(3)-5-(pyridine-4-carboxamido)­isophthalato]cobalt(II)digadolinium(III)] tetra­hydrate]

In the centrosymmetric polymeric title compound, {[CoGd(2)(C(14)H(8)N(2)O(5))(4)(H(2)O)(4)]·4H(2)O}(n), the Gd(III) cation is coordinated by one water mol­ecule and four pyridine-4-carboxamido­isophthalate (L) anions in a distorted square-anti­prismatic arrangement, while the Co(II) cation, located on an inversion center, is coordinated by two pyridyl-N atoms, two carboxyl­ate-O atoms and two water mol­ecules in a distorted octa­hedral geometry. The asymmetric unit contains two anionic L ligands: one bridges two Gd cations and one Co cation through two carboxyl groups and one pyridine-N atom; the other bridges two Gd cations and one Co cation through two carboxyl groups and the uncoordinated pyridine-N atom is hydrogen-bonded to the adjacent coordinated water mol­ecule. Extensive O—H⋯O and N—H⋯O hydrogen bonds are present in the crystal structure.