Dimeric Molecules in the Crystals of a Calcium(II) Complex with Pyridine-2,6-Dicarboxylate and Water Ligands

The crystals of bis w -pyridine-2,6-dicarboxylato-O,N,O')]bistrisaqua-calcium(II)] di(pyridine-2,6-dicarboxylic acid) contain dimeric molecules composed of two calcium(II) ions and two ligand molecules. Calcium ions are bridged by two bidentate oxygen atoms each donated by one carboxylic group of the ligand Ca―N 2.467(2)Å], a monodentate oxygen atom of the second carboxylate group of the ligand Ca―N 2.484(2)Å] and three oxygen atoms donated by the water molecules mean Ca―O 2.388(2)Å]. The coordination polyhedron is a distorted pentagonal bipyramid. Acid molecules were found to be located in the space between dimers and involved in an extended network of hydrogen bonds.