Poly[[bis­{μ(2)-1,2-bis­[(1H-imidazol-1-yl)meth­yl]benzene}(μ(4)-9,10-dioxo-9,10-dihydro­anthracene-1,4,5,8-tetra­carbox­yl­ato)dicobalt(II)] dihydrate]

The title complex, {[Co(2)(C(18)H(4)O(10))(C(14)H(14)N(4))(2)]·2H(2)O}(n) was synthesized from CoCl(2)·6H(2)O, 9,10-dioxo-9,10-dihydro­anthracene-1,4,5,8-tetra­carb­oxy­lic acid (H(4)AQTC) and 1,2-bis­[(1H-imidazol-1-yl)meth­yl]benzene (o-bix) in water. The anthraquinone unit is located about a crystallographic center of inversion. Each asymmetric unit therefore contains one Co(II) atom and one o-bix ligand, as well as half an AQTC(4−) ligand and an additional solvent water mol­ecule. The Co(II) ions are tetra­hedrally surrounded by two O atoms from two AQTC(4−) anions and by two N atoms from two o-bix ligands, forming a two-dimensional coordination polymer. The solvent water mol­ecules are connected to the carboxyl­ate groups by O—H⋯O hydrogen bonds. Additional weak C—H⋯O hydrogen bonds are observed in the crystal structure.