Date Published: July 01, 2011
Publisher: International Union of Crystallography
Author(s): Gang Zhang, Yong Wang.
The asymmetric unit of the title compound, [Cd(C7H7N2O4)2(H2O)2]·2H2O, consists of one CdII ion, one 4-carboxy-2-ethyl-1H-imidazole-5-carboxylate anion, one coordinated water molecule and one lattice water molecule. The CdII ion lies on a twofold axis, and is hexacoordinated by four O atoms from water molecules and carboxylate groups and two N atoms from two imidazole rings, in a distorted octahedral arrangement. An extensive framework of N—H⋯O and O—H⋯O hydrogen bonds with the participation of coordinated and free water molecules is found in the crystal structure, which contributes to the formation of a three-dimensional structure.
For coordination polymers built up from related imidazole–carboxylate ligands, see: Li et al. (2011 ▶); Wang et al. (2008 ▶); Zhang et al. (2010 ▶); Tian et al. (2010 ▶). For a related CdII complex based on the ligand 5-carboxy-2-methyl-1H-imidazole-4-carboxylate, see: Nie et al. (2007 ▶).