Syntheses, Structures, and Properties of Four New Metal-Organic Frameworks Bases on Imidazole Ligands and 5-Amino-2,4,6-triodoisophthalic Acid

Four metal-organic coordination polymers, [Zn(L-1)(2)(L-2)(2)](n) (1), [Cd(L-1)2(L-2)(2)(H2O)(2)](n) (2), [Ni(L-1)(2)(L-2)(2)(H2O)(2)](n) (3), and [Co(L-1)(2)(L-2)(2)(H2O)(2)](n) (4), (L-1 = 4,4,bis(1-imidazoly)biphenyl, L-2 = 5-amino-2, 4, 6-triodoisophthalic acid) have been hydrothermally synthesized and characterized by elemental analyses, IR, TG, PXRD, luminescent properties and single-crystal X-ray diffraction. X-ray structure analysis reveals that 1 is a 2D coordination polymer, while 2, 3, and 4 are 1D coordination polymers. The 3D structures of the four complexes are stabilized by pi-pi stacking and hydrogen-bonds.