The reaction of the proton-transfer compound (pdaH2)(py- 3,5-dc)H2O (pda = propane-1,3-diamine and py-3,5-dcH2 = pyridine-3,5-dicarboxylic acid) with Ba(NO3)2 leads to the formation of the title polymeric compound, [Ba(C7H3NO4)- (H2O)3]n. The BaII atom is nine-coordinated by six carboxylate O atoms from the (py-3,5-dc)2 ligands, and three O atoms from the coordinated water molecules. The coordination polyhedron around the BaII atom is best described as tricapped trigonal-prismatic. In the crystal structure, intermolecular interactions, such as X—H O hydrogen bonds (X = O and C) and – stacking [centroid–centroid distances between pyridine rings of 3.6191 (13) and 3.6192 (13) A ° ] play an important role in stabilizing the supramolecular structure.
