Poly[[aqua-μ6-benzene-1,2,3-tricarboxylato-μ3-hydroxido-dizinc] hemihydrate]

Abstract

In the title compound, {[Zn2(C9H3O6)(OH)(H2O)]·0.5H2O}n, there are three independent ZnII atoms present; two are located on special positions, viz a twofold rotation axis and an inversion centre, and the third is located in a general position. The ZnII atom on the inversion centre is six-coordinated by four O atoms from four different benzene-1,2,3-tricarboxylate anions and two OH− anions. The ZnII atom located on a twofold axis is four coordinated by two O atoms from two different benzene-1,2,3-tricarboxylate anions and two OH− anions. The third ZnII atom, located in a general position, is five coordinated by three O atoms from three different benzene-1,2,3-tricarboxylate anions, one OH− anion and one water molecule. Each benzene-1,2,3-tricarboxylate anion bridges six ZnII atoms, and the OH− anion bridges three ZnII atoms, resulting in the formation of a three-dimensional framework. A series of O—H...O hydrogen bonds involving the benzene-1,2,3-tricarboxylate anions, the OH− anion and the coordinating and the two water solvent molecules further stablize the crystal structure. The two solvent water molecules show occupancies of 0.5 and 0.25.