Poly[tetra-aqua-μ(3)-pyridine-3,5-dicarboxyl-ato-strontium(II)].

The reaction of strontium(II) nitrate with the proton-transfer compound (pdaH(2))(py-3,5-dc)·H(2)O (where pda = propane-1,3-diamine and py-3,5-dcH(2) = pyridine-3,5-dicarboxylic acid) leads to the formation of the title polymeric compound, Sr(C(7)H(3)NO(4))(H(2)O)(4). The propane-1,3-diaminium cation is not incorporated in this crystal structure. The Sr(II) 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 mol-ecules. The coordination polyhedron of the Sr(II) atom is a distorted dodeca-hedron. These binuclear units are connected via the carboxyl-ate O atoms to build a one-dimensional polymeric chain. In the crystal structure, non-covalant inter-actions consisting of hydrogen bonds (X-H⋯O, with X = O and C) and π-π stacking inter-actions [3.4604 (19) Å] connect the various components to form a supra-molecular structure.