Syntheses, Structures, Luminescence, and Photocatalytic Properties of a Series of Uranyl Coordination Polymers

A new series of uranium coordination polymers have been hydrothermally synthesized by using 4,4'-oxidiphthalic acid (H4L) in the presence of N-bearing species, namely, (H(2)dpa)UO2L.3H(2)O (1), (H(2)dib)UO2L.H2O (2), (H(2)bbi)(UO2)L.3H(2)O (3), (H(2)dib)(dib)(0.5)[UO2L(dib)].3H(2)O (4), (H(2)bbi)(U2O5)L.2H(2)O (5), and (Hbpi)(2)(UO(2)F())2L (6) [dpa = di(pyridin-4-yl)amine, dib = 1,4-di(1H-imidazol-1-yl)benzene, bbi = 1,1'-(1,4-butanediyl)bis(imidazole), and bpi = 1-(biphenyl-4-yl)-1H-imidazole]. Compounds 13 exhibit the ribbon structures with dpa, dib, and bbi as the templates, respectively. Compound 4 represents a one-dimensional chain assembly of uranyl centers, L ligands, and coordinated dib molecules. Compound 5 contains the tetranuclear motifs of edge-sharing of two UO7 pentagonal and two UO8 hexagonal bipyramids, which are linked by L ligands forming a layered structure with bbi as the template. Compound 6 forms a two-dimensional arrangement, in which the chain structures of edge-sharing UO5F2 pentagonal bipyramids are pillared by L ligands. Luminescence studies reveal the characterized green light emission from uranyl centers for these uranyl carboxylates. Moreover, the excellent visible light photodegradation activities for RhB are displayed by these coordination polymers.