Poly[[tri-μ-aqua-dodecaaquatris(μ3-1-hydroxyethylidene-1,1-diphosphonato)tricalcium(II)tripalladium(II)] pentahydrate]

Abstract

The asymmetric unit of the title compound, {[CaPd{CH3OHC(PO3)2}(H2O)5]·5/3H2O}n, consists of one half of the complex [Pd{CH3OHC(PO3)2}]2− anion (point group symmetry m..), one Ca2+ 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 [Ca2(H2O)10]2+ dimer. The slightly distorted square-planar coordination environment of the PdII 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.

Keywords

• crystal structure