The title compound, [Sr7(C7H3NO4)6(SO4)(H2O)6]n, has been synthesized by an ionothermal method using the ionic liquid 1-ethyl-3-methylimidazolium ([Emim]Br) as solvent, and characterized by elemental analysis, energy-dispersive X-ray spectroscopy, IR and single-crystal X-ray diffraction. The structure of the compound can be viewed as a three-dimensional coordination polymer composed of Sr(2+) cations, pyridine-2,6-dicarboxylate anions, sulfate anions and water molecules. The compound not only exhibits a three-dimensional structure with a unique coordination mode of the sulfate anion, but also features the first example of a heptanuclear strontium(II) coordination polymer. The structure is further stabilized by O-H···O hydrogen bonds and π-π stacking interactions.
Keywords: crystal structure; heptanuclear strontium(II) coordination polymer; hydrogen bonding; ionothermal synthesis; sulfate ligand.