Syntheses, structures, and fluorescent properties of two uranium coordination polymers with carboxylic acids

Abstract

Two U(VI)-containing coordination polymers, (UO₂)₂O₂(Suc)(2,2′-bipy)₂ (1) and UO₂(BC)₂(DMF) (2) (2,2′-bipy = 2,2′-bipyridine, H₂Suc = succinic acid, HBC = benzoic acid, DMF = N,N-dimethylformamide), have been synthesized and characterized via elemental analysis, infrared spectroscopy, UV-Vis spectroscopy, and single-crystal X-ray diffraction. Structural analyses show that 1 is a 1-D chain coordination polymer in which U(VI) ions are connected by succinic acid ligand and the 1-D chain is connected into a 3-D supramolecular network by C⊟H···O hydrogen bonds between carbon of 2,2′-bipyridine and uranyl oxygen. For 2, monomeric entities are further assembled into a 1-D supramolecular network by C–H···O hydrogen bonds between carbon of DMF molecule and coordinated carboxylate oxygen. Thermogravimetric analyses and photoluminescent properties of 1 and 2 are discussed.

Keywords:

• Uranium coordination polymers
• Crystal structure
• Photoluminescent properties
• Hydrogen-bonding
• Supramolecular assembly

Acknowledgments

This work was supported by the grants of the National Natural Science Foundation of China (No. 21071071) and State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China (Grant No. 2010–15).