Syntheses, Structures And Properties Of Coordination Polymers With Bis(2-methylimidazole)

Imidazole and its deriverties are used to build metal-organic coordination polymers. Bis(2-methylimidazole) as a bridging role may form a unique topolygy and novel coordination polymers.In the work, nine coordination polymers {[Co2(bib)(ada)2]·0.5H2O}n(1), {[Co(bib)(NH2bdc)]·H2O}n(2), {[Co(bib)(ndc)]·0.5H2O}n(3), [Cd2(bib)(bdc)2]n(4), Cd2(bib)(bda)2]n(5), [Cu2(bib)(glu)2]n(6), {[Zn(bib)(ndc)]·0.25H2O}n(7), [Ni(bib)(hip)]n(8) and {[Ni2(bib)(ada)2]·0.5H2O}n(9) were synthesized by using flexible ligand 1,4-bis(2-methylimidazol-1-yl) butane(bib) and transition metal cations Co(II), Cd(II), Cu(II), Zn(II), Ni(II) and muticarboxylates 1, 3-adamantanedicarboxylic acid(H2ada), 5-aminoisophthalic acid(H2aip), 5-hydroxyisophthalic acid(H2hip), 1, 4-naphthalenedicarboxylate acid(H2ndc), 1, 2-benzenedicarboxylic acid(H2bdc), 1, 4-benzenediacetate acid(H2bda), glutaric acid(H2glu).The structures of these coordination polymers have been determined. Ligand bib as a bridge to connect two centers presents the anti-anti-gauche conformation in coordination polymers 1, 8 and 9, while anti-anti-anti conformation in 2, 3 and 4, and gauche-anti-gauche conformation in 5, 6 and 7. In these coordination polymers, 1 and 9 are isostructural showing the 1D triple-stranded chain with double ada and one bib bridges. 8 shows a special 2D(6, 3) network. 2 exhibits an unusual(3, 4)-connected 2D network, while 4 displays the 6-connected self-catenated 3D network based on Cd2(COO)2 dimer and 5 shows the 3-fold interpenetrating 3D pcu network based on Cd2(COO)2 dimer. 3 and 7 are similar, which show the 4-fold interpenetrating 4-connected 3D dia network. Different structures were formed by changing the muticarboxylates and the central atoms. The different conformations of bib ligands in coordination polymers play the key role in the construction of different structures.These compounds were characterized by X-Ray Powder Diffraction analyses, IR and UV. Luminescence, thermogravi-metric analysis and photocatalytic activity were also investigated. 5, 6 and 9 exhibit good photocatalytic activity for the degradation of methyl orange.