Crystal structure of poly[[μ(2)-di­aqua-di­aqua-μ(2)-l-proline-κ(2) O:O′-strontium] dibromide]

In the title coordination polymer, {[Sr(C(5)H(9)NO(2))(H(2)O)(4)]Br(2)}(n), the proline mol­ecule exists in a zwitterionic form with one of the ring C atoms disordered over two sites [site-occupancy factors = 0.57 (6):0.43 (6)]. The Sr(II) ion is nine-coordinated by six water O atoms, two monodentate and two μ(2)-bridging, and three carboxyl­ate O atoms of the proline ligands, with two bridging [Sr—O range = 2.524 (4)–2.800 (5) Å]. In the crystal, there is no direct inter­action between the proline mol­ecules. However, the proline and water mol­ecules associate with the bromide counter-anions through a number of inter­molecular O—H⋯Br and N—H⋯Br hydrogen-bonding inter­actions, giving a three-dimensional supra­molecular structure.