Polymeric strontium ranelate nona­hydrate

The title compound, poly[[μ-aqua-tetra­aqua{μ-5-[bis­(carboxyl­atometh­yl)amino]-3-carboxyl­atomethyl-4-cyano­thio­phene-2-carboxyl­ato}distrontium(II)] tetra­hydrate], [Sr(2)(C(12)H(6)N(2)O(8)S)(H(2)O)(5)]·3.79H(2)O, crystallizes with nine- and eight-coordinated Sr(2+) cations. They are bound to seven of the eight ranelate O atoms and five of the water mol­ecules. The SrO(8) and SrO(9) polyhedra are inter­connected by edge-sharing, forming hollow layers parallel to (011). The layers are, in turn, inter­connected 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.