Novel Uranyl Coordination Polymers Based on Quinoline-Containing Dicarboxylate by Altering Auxiliary Ligands: From 1D Chain to 3D Framework

Abstract

Novel uranyl coordination polymers, UO2(bqdc)(phen)·H2O (1), [UO2(μ-OH)(bqdc)(H2bpy)0.5(H2O)] (2), Na[(UO2)2(bqdc)3Na(H2O)2] (3), and [Na(bqdc)0.5(bpp)(H2O)] (4) (H2bqdc = 2,2′-biquinoline-4,4′-dicarboxylic acid; phen = 1,10-phenanthroline; bpy = 4,4′-bipyridine; bpp = 1,3-di(4-pyridyl)propane), with bqdc2– ligands have been successfully synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, Infrared spectroscopy (IR), thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). The topological structures feature 1D chain to 3D framework by altering N-donor ancillary ligands. Compound 1 shows a 1D wave-shaped zigzag chain structure and further extends to a two-dimensional (2D) layer through π···π interactions between the quinoline ring of bqdc2– ligand and benzene ring of phen ligand. The uranium adopts an approximate hexagonal bipyramidal coordination geometry with the equatorial plane warped to the unusual chair conformation. Compound 2 features rectangula...