Synthesis, Crystal Structures and Photoluminescent Properties of One-Dimensional Europium(III)- and Terbium(III)-Glutarate Coordination Polymers, and Their Applications for the Sensing of Fe and Nitroaromatics.

Two lanthanide-glutarate coordination polymers, . : {[Eu(CHO)(HO)]Cl} , () and [Tb(CHO)(CHO)(HO)] , () have been synthesized and characterized by IR spectroscopy, thermogravimetric analysis, and X-ray crystallography. In , the Eu(III) ions are coordinated by four O atoms from two bidentate chelating carboxylate groups, one O atom from a bridging carboxylate group and four O atoms from water molecules adopting an EuO distorted tri-capped trigonal prismatic coordination geometry. In , the Tb(III) ions are coordinated by six O atoms from three bidentate chelating carboxylates, one O atom from a bridging carboxylate and two O atoms from water molecules to generate distorted tri-capped trigonal prismatic TbO polyhedron. In both compounds, the metal polyhedra share edges, producing centrosymmetric LnO diamonds, and are linked into [001] chains by bridging glutarate di-anions. The crystal structures are consolidated by O-H···O and O-H···Cl hydrogen bonds in , and O-H···O hydrogen bonds in . Compound exhibits a red emission attributed to the D → F ( = 1-4) transitions of the Eu(III) ion, whereas displays green emission corresponding to the D → F ( = 0-6) transitions of the Tb(III) ion. Both the compounds exhibit high sensitivity and selectivity for Fe ions due to luminescence quenching compared with other metal ions, which include; Na, Mg, Al, Cr, Mn, Fe, Co, Ni, Zn and Cd. Compounds and also show high luminescence quenching sensitivity for 4-nitrophenol over the other aromatic and nitroaromatic compounds, namely; bromobenzene, 1,3-dimethylbenzene, nitrobenzene, 4-nitrotolune, 4-nitrophenol, 2,6-dinitrophenol and 2,4,6-trinitrophenol.