catena-Poly[[[aqua­(1,10-phenan­throline)cadmium(II)]-μ-benzene-1,4-dicarboxyl­ato] benzene-1,4-dicarboxylic acid hemisolvate]

A new cadmium(II) coordination polymer, {[Cd(C(8)H(4)O(4))(C(12)H(8)N(2))(H(2)O)]·0.5C(8)H(6)O(4)}(n), has been synthesized under hydro­thermal conditions. The asymmetric unit contains one Cd(II) atom, one benzene-1,4-dicarboxyl­ate anion, one 1,10-phenanthroline ligand, one coordinated water mol­ecule and half of an uncoordinated benzene-1,4-dicaboxylic acid solvent mol­ecule. The Cd(II) atom is in the centre of a monocapped distorted octa­hedron made up of four O atoms of two chelating benzene-1,4-dicarboxyl­ate anions, one water O atom and two 1,10-phenanthroline N atoms. The metal centres are connected via bis-chelating benzene-1,4-dicarboxyl­ate anions into a zigzag chain structure along [001]. These chains are further connected by O—H⋯O hydrogen bonds between the water mol­ecules and adjacent carboxyl­ate O atoms. Additional O—H⋯O hydrogen bonding between the uncoordinated benzene-1,4-dicaboxylic acid mol­ecules along [010] consolidates the structure.