catena-Poly[[[triaquacopper(II)]-μ2-pyrazine-2,3-dicarboxylato] monohydrate]

The Cu atom in the title complex, {[Cu(C6H2N2O4)(H2O)3]·H2O}n or {[Cu(L)(H2O)3]·H2O}n (L is pyrazine-2,3-dicarboxylate), displays octahedral coordination formed by the ligand L and three coordinated water molecules. The ligand L is tridentate, with one N atom of the pyrazine ring and one O atom of one carboxylate group forming a chelate ring, whereas one O atom from the second carboxylate group is coordinated to another Cu atom. The ligand L links molecules to form an infinite chain parallel to the [101] direction. The chains are further linked through O—H⋯O and O—H⋯N hydrogen bonds involving the water molecules to build up a three-dimensional network.