Dimeric molecules in the crystals of calcium complex with pyridine-3,5-dicarboxylate ligand

The crystals of di[pentaquo(pyridine-3,5-dicarboxylato, O,O')]dicalcium(II) dihydrate contain dimeric molecules in which two Ca(II) ions are bridged by carboxylate oxygen atoms donated by only one carboxylic group of each ligand molecule [Ca-O 2.443(2) and 2.340(1) Angstrom]. The sevenfold coordination around each Ca(II) ion is completed by oxygen atoms of five water molecules with Ca-O bond distances ranging from 2.392(2) to 2.429(2) Angstrom. The coordination around the Ca(II) ion is a distorted pentagonal bipyramid. A network of hydrogen bonds operating via two hydration water molecules is responsible for the stability of the crystal.