Poly[propane-1,3-diammonium [cuprate(II)-bis­(μ(2)-pyridine-2,3-dicarboxyl­ato)] trihydrate]

The title polymeric compound {(C(3)H(12)N(2))[Cu(C(7)H(3)NO(4))(2)]·3H(2)O}(n) or {(pnH(2))[Cu(py-2,3-dc)(2)]·3H(2)O}(n) (pn is propane-1,3-diamine and py-2,3-dcH(2) is pyridine-2,3-dicarboxylic acid), was synthesized by reaction of copper(II) chloride dihydrate with a proton-transfer compound, propane-1,3-diammonium pyridine-2,3-dicarboxyl­ate or (pnH(2))(py-2,3-dc), in aqueous solution. The anion is a six-coordinate complex (site symmetry [Image: see text]), with a distorted octa­hedral geometry around Cu(II), consisting of two bidentate pyridine-2,3-dicarboxyl­ate groups and two O atoms of bridging ligands from (py-2,3-dc)(2−) fragments, which are located in trans positions. The (pnH(2))(2+) cation is disordered over two sites by the center of inversion. Inter­molecular hydrogen bonds, π–π [centroid–centroid distances of 3.539 (3) Å] and C—O⋯π stacking inter­actions [O⋯Cg = 3.240 (5) Å; Cg is the center of the pyridine ring], connect the various components into a supra­molecular structure.