MOLECULAR CHAINS IN THE CRYSTALS OF A CALCIUM(II) COMPLEX WITH PYRIDINE-3,5-DICARBOXYLATE (DINICOTINATE) AND WATER LIGANDS

摘要

The crystal of pentaqua (catena-pyridine-3,5-dicarboxylato-O,O) calcium(II) Contain zigzag molecular chains composed of Ca ions linked by two bridging oxygen atoms, each donated by one carboxylate group [Ca-O1 2.353(2) A, Ca-O3~(III) 2.334(1) A]. The Ca ions, the ligand molecules and one water oxygen atom coordinated by each metal ion [Ca-O5 2.410(2) A] are coplanar. The coordination of the Ca ion is completed by four other water oxygen atoms situated above and below the plane of the chain [Ca-06 2.475(1)A, Ca-07 2.371(2) A]. The coordination number of the calcium(II) ion is seven. The water molecules act as donors in a system of hydrogen bonds.