Polymeric strontium ranelate nonahydrate

The title compound,poly[[μ-aqua-tetra-aqua{μ-5-[bis- (carboxylatomethyl)amino]-3-carboxylatomethyl-4-cyano-thio-phene-2-carboxylato} distrontium(II)] tetrahydrate],[Sr₂(C₁₂H₆N ₂O₈S)(H₂O)5]·3.79H₂O, crystallizes with nine- and eight-coordinated Sr²⁺ cations. They are bound to seven of the eight ranelate O atoms and five of the water molecules. The SrO₈ and SrO₉ polyhedra are inter-connected by edge-sharing, forming hollow layers parallel to (011). The layers are, in turn, inter-connected by ranelate anions, forming a metal-organic framework (MOF) structure with channels along the a axis. The four water molecules not coordinated to strontium are located in these channels and hydrogen bonded to each other and to the ranelates. Part of the water H atoms are disordered. The compound dehydrates very easily and 0.210 (4) water molecules out of nine were lost during crystal mounting causing additional disorder in the water structure.