Crystal structure of catena-poly[[cadmium(II)-di-μ2-bromido-μ2-l-proline-κ(2) O:O'] monohydrate]

In the title coordination polymer, {[CdBr2(C5H9NO2)]·H2O} n , the Cd(II) ion is coordinated by four bromido ligands and two carboxyl-ate oxygen atoms of two symmetry-related proline ligands, which exist in a zwitterionic form, in a distorted octa-hedral geometry. There is an intra-molecular N-H⋯O hydrogen bond between the amino group and the carboxyl-ate fragment. Each coordinating ligand bridges two Cd(II) atoms, thus forming polymeric chains running along the c-axis direction. The water mol-ecules of crystallization serve as donors for the weak inter-molecular O-H⋯O and O-H⋯Br hydrogen bonds that link adjacent polymeric chains, thus forming a three-dimensional structure. N-H⋯O and N-H⋯Br hydrogen bonds also occur.