Poly[[μ-aqua-aqua[μ4-ethyl (dichloromethylene) diphosphonato]sesquicalcium(II)] acetone hemisolvate 4.5-hydrate]

The title compound, {[Ca-1.5(C3H5Cl2O6P2)(H2O)(2)]-0.5CH(3)COCH(3)center dot 4.5H(2)O}(n), has a two-dimensional polymeric structure. The asymmetric unit contains two crystallographically independent Ca2+ cations connected by a chelating and bridging ethyl (dichloromethylene) diphosphonate(3(-)) ligand and an aqua ligand. One of the Ca atoms, lying on a centre of symmetry, has a slightly distorted octahedral 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 center dot center dot center dot O hydrogen bonding into a three-dimensional supramolecular network. The acetone solvent molecule and one uncoordinated water molecule are located on twofold rotation axes.