Crystal structure of catena-poly[[[tri-aqua-strontium]-di-μ2-glycinato] dibromide]

In the title coordination polymer, {[Sr(C2H5NO2)2(H2O)3]Br2} n , the Sr(2+) ion and one of the water mol-ecules are located on twofold rotation axes. The alkaline earth ion is nine-coordinated by three water O atoms and six O atoms of the carboxyl-ate groups of four glycine ligands, two in a chelating mode and two in a monodentate mode. The glycine mol-ecule exists in a zwitterionic form and bridges the cations into chains parallel to [001]. The Br(-) counter-anions are located between the chains. Inter-molecular hydrogen bonds are formed between the amino and carboxyl-ate groups of neighbouring glycine ligands, generating a head-to-tail sequence. Adjacent head-to-tail sequences are further inter-connected by inter-molecular N-H⋯Br hydrogen-bonding inter-actions into sheets parallel to (100). O-H⋯Br and O-H⋯O hydrogen bonds involving the coordinating water mol-ecules are also present, consolidating the three-dimensional hydrogen-bonding network.