Preparation, structures, and photocatalytic properties of three new uranyl-organic assembly compounds

Three new uranyl-organic coordination polymers (UO2)8(NDC)12(4,4'-bipyH2)3(4,4'-bipyH)3 (1), (UO2)3O[Ag(2,2'-bipy)2]2(NDC)3 (2), and (UO2)2(NDC)2(2,2'-bipy)2 (3), where NDC=1,4-naphthalenedicarboxylate and bipy=bipyridine, have been prepared in hydrothermal conditions. Both 1 and 2 possess a 2D structure while 3 is composed of 1D zigzag chains. In 1 there are mononuclear pentagonal-bipyramidal U-O polyhedra and 1D channels filled with 4,4'-bipy molecules, whereas in 2 there are mononuclear hexagonal-bipyramidal U-O polyhedra and tetranuclear pentagonal-bipyramidal U-O clusters which form 2D channels with occluded [Ag(2,2'-bipy)2]+ counterions. In 3 both the NDC and the bipy ligands coordinate to uranyl centers, leading to hexagonal-bipyramidal polyhedra which are connected to form 1D zigzag chains. Under UV or visible irradiation, 1 and 2 degrade rhodamine B with similar efficiency. The correlation between photocatalytic reaction rate and oxygen concentration for 1 and 2 has also been elucidated. Crystal data: 1, triclinic, space group P1, a=11.037(2) A, b=15.126(3) A, c=15.660(3) A, alpha=62.05(3) degrees, beta=72.26(3) degrees, gamma=82.05(3) degrees, and Z=2; 2, triclinic, space group P1, a=14.161(3) A, b=15.122(3) A, c=18.212(4) A, alpha=85.73(3) degrees, beta=76.99(3) degrees, gamma=67.32(3) degrees, and Z=2; 3, monoclinic, space group P2(1)/n, a=10.7976(18) A, b=31.501(6) A, c=11.590(2) A, beta=97.609(4) degrees, and Z=4.