Popis: |
The title compound, [Ca(C3H3O4)2]n, has a polymeric structure, built up from noncentrosymmetric Ca2O12 face-sharing bipolyhedra, linked through the spacers of the ligands and forming a complex three-dimensional framework containing empty channels parallel to the [001] direction. The calcium ion lies on a 2 axis and is coordinated by eight O atoms from six hydrogen malonate ligands in a distorted bicapped dodecahedron. The tridentate ligand displays an η5-chelating coordination mode and forms both μ1,1 and μ1,3 bridges. In the extended network, the protonated O atom is involved in a strong hydrogen bond with a deprotonated O atom, forming an infinite array of the ligands. An M—O—M infinite linkage characteristic of metal–organic frameworks is prevented here by cage assembly around the metal. |