catena-Poly[[diaqua­cobalt(II)]-μ(2)-7-oxa­bicyclo­[2.2.1]heptane-2,3-dicarboxyl­ato-κ(4) O (2),O (3),O (7):O (2′)]

The polymeric title complex, [Co(C(8)H(8)O(5))(H(2)O)(2)](n) was synthesized by reaction of cobalt acetate with 7-oxabicyclo­[2,2,1]heptane-2,3-dicarb­oxy­lic anhydride. The Co(II) ion is six-coordinated in a distorted octa­hedral environment, binding to two water O atoms, to the ether O atom of the bicyclo­heptane unit, to two carboxyl­ate O atoms from two different carboxyl­ate groups of the same anion and to one carboxyl­ate O atom from a symmetry-related anion. The bridging character of the dianion leads to the formation of ribbons along [001]. The ribbons are linked into a layered network parallel to (010) by several O—H⋯O hydrogen-bonding inter­actions involving the coordinating water mol­ecules as donors and the carboxyl­ate O atoms of neighbouring ribbons as acceptors. The crystal under investigation was an inversion twin.