Poly[propane-1,3-diammonium [cuprate(II)-bis-(μ(2)-pyridine-2,3-dicarboxyl-ato)] 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-dicarboxyl-ate or (pnH(2))(py-2,3-dc), in aqueous solution. The anion is a six-coordinate complex (site symmetry ), with a distorted octa-hedral geometry around Cu(II), consisting of two bidentate pyridine-2,3-dicarboxyl-ate 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. Inter-molecular hydrogen bonds, π-π [centroid-centroid distances of 3.539 (3) Å] and C-O⋯π stacking inter-actions [O⋯Cg = 3.240 (5) Å; Cg is the center of the pyridine ring], connect the various components into a supra-molecular structure.