Poly[[μ-aqua-aqua-[μ(4)-ethyl (dichloro-methyl-ene)diphospho-nato]sesqui-calcium(II)] acetone hemisolvate 4.5-hydrate].

The title compound, {[Ca(1.5)(C(3)H(5)Cl(2)O(6)P(2))(H(2)O)(2)]·0.5CH(3)COCH(3)·4.5H(2)O}(n), has a two-dimensional polymeric structure. The asymmetric unit contains two crystallographically independent Ca(2+) cations connected by a chelating and bridging ethyl (dichloro-methyl-ene)diphos-pho-n-ate(3(-)) ligand and an aqua ligand. One of the Ca atoms, lying on a centre of symmetry, has a slightly distorted octa-hedral geometry, while the other Ca atom is seven-coordinated in a distorted monocapped trigonal-prismatic geometry. The polymeric layers are further connected by extensive O-H⋯O hydrogen bonding into a three-dimensional supra-molecular network. The acetone solvent mol-ecule and one uncoordin-ated water mol-ecule are located on twofold rotation axes.