The reaction of strontium(II) nitrate with the proton-transfer compound (pdaH2)(py-3,5-dc)H2O (where pda = propane- 1,3-diamine and py-3,5-dcH2 = pyridine-3,5-dicarboxylic acid) leads to the formation of the title polymeric compound, [Sr(C7H3NO4)(H2O)4]n. The propane-1,3-diaminium cation is not incorporated in this crystal structure. The SrII atom lies on an inversion centre and is eight-coordinated by four O atoms from three py-3,5-dc ligands and four O atoms from four coordinated water molecules. The coordination polyhedron of the SrII atom is a distorted dodecahedron. These binuclear units are connected via the carboxylate O atoms to build a one-dimensional polymeric chain. In the crystal structure, non-covalant interactions consisting of hydrogen bonds (X— H O, with X = O and C) and – stacking interactions [3.4604 (19) A ° ] connect the various components to form a supramolecular structure.
