Synthesis and characterization of calcium(II) coordination polymers based on phenylacetic acid

Abstract

The syntheses, crystal structures, and thermal properties of the coordination polymers [Ca(H2O)2(L1)2].H2O (1) (L1 = 4-methoxyphenylacetate) and [Ca(H2O)2(L2)2].2H2O (2) (L2 = 2-chlorophenylacetate) are described. 1 and 2 can be dehydrated to the anhydrous [Ca(L1)2] (1a) or [Ca(L2)2] (2a), respectively. Compounds 1 and 2 crystallize in the non-centrosymmetric monoclinic space group P21 and the structures consist of a central Ca(II), two terminal waters, and two crystallographically unique L1 (or L2) anions, one of which functions as a chelating bidentate ligand. The second independent L1 (or L2) is tetradentate, coordinated in a 3-bridging mode leading to the formation of a 1-D coordination polymer. In the infinite chain extending along the b-axis, each Ca(II) is eight-coordinate and bonded to two terminal waters and six oxygens from four different L1 or L2 ligands.