Poly[[tri-μ-aqua-do­deca­aqua­tris­(μ(3)-1-hy­droxy­ethyl­idene-1,1-di­phospho­nato)tricalcium(II)tripalladium(II)] penta­hydrate]

The asymmetric unit of the title compound, {[CaPd{CH(3)OHC(PO(3))(2)}(H(2)O)(5)]·5/3H(2)O}(n), consists of one half of the complex [Pd{CH(3)OHC(PO(3))(2)}](2−) anion (point group symmetry m..), one Ca(2+) cation [site symmetry (.2.)] that is surrounded by three water mol­ecules (one of which is on the same rotation axis) and by three disordered lattice water mol­ecules. The anions form a trinuclear metallocycle around a crystallographic threefold rotation axis. The cations are related by a twofold rotation axis to form a [Ca(2)(H(2)O)(10)](2+) dimer. The slightly distorted square-planar coordination environment of the Pd(II) atoms in the complex anions is formed by O atoms of the bidentate chelating phospho­nate groups of the 1-hy­droxy­ethyl­idene-1,1-di­phospho­nate ligands. In the crystal, cations are bound to anions through —Ca—O—P—O— bonds, as well as through O—H⋯O hydrogen bonds, resulting in a three-dimensional polymer. The structure is completed by five disordered solvent mol­ecules localized in cavities within the framework.