catena-Poly[[triaqua­chlorido-μ(3)-malonato-cerium(III)] hemihydrate]

The asymmetric unit of the title compound, {[Ce(C(3)H(2)O(4))Cl(H(2)O)(3)]·0.5H(2)O}(n), contains a Ce(3+) atom coordinated by a chloride anion, three water mol­ecules and a malonate ligand, and one water mol­ecule of crystallization with a factor of occupancy of 50%. The malonate ligand is bonded to three different symmetry-related metal atoms yielding a one-dimensional coordination polymer running parallel to the a axis. A supra­molecular network composed of strong and highly directional O—H⋯O and O—H⋯Cl hydrogen bonds ensures a close and effective packing of adjacent polymeric chains.