Syntheses, Structures and Photocatalytic Degradation Properties of Two Copper(II) Coordination Polymers with Flexible Bis(imidazole) Ligand

Two copper(II) coordination polymers {[Cu(bib)(nip)]center dot 1.5H(2)O}(n) (1) and [Cu-2(bib)(glu)(2)]n (2) (bib = 1,4-bis(2-methyl-imidazol-1-yl)butane, H(2)nip = 5-nitroisophthalic acid, H(2)glu = glutaric acid) were synthesized by the hydrothermal method and characterized by single-crystal X-ray diffraction, elemental analyses, IR and solid-state diffuse-reflection spectra. 1 forms a 2D network with the point symbol of (4(4).6(2)) and 2D -> 2D polythreaded network. 2 constructs the 6-connected 3D network based on the [Cu-2(COO)(2)] dimer with the point symbol of (4(4). 6(10).8) The energy band gaps (E-g) of 1 and 2 were 2.453 and 2.162 eV, respectively. 1 and 2 present high photocatalytic activity for the degradation of methylene blue under visible light irradiation.