Three Silver(I) Coordination Polymers Constructed from Flexible Bis(benzimidazole) and Carboxylates Ligands

Under hydrothermal conditions three new Ag-I coordination polymers, [Ag(L1)(Hmip)](n) [Ag(L2)(0.5)(ndc)(0.5)](n) (2), and ([Ag(L3)(0.5)(Htbi)]center dot 0.25H(2)O) (3) [H(2)mip = 5-methylisophthalic acid, L1 = 1,4-bis(2-methylbenzimidazol-1-ylmethyl)benzene,H(2)ndc = 2,6-naphthalenedicarboxylic acid, L2 = 1,3-bis(2-methylbenzimidazol-1ylmethyl)benzene, H(2)tbi = 5-tert-butyi isophthalic acid, L3 = 1,4-bis(5,6-dimethylbenzimidazole)butane] were synthesized by employing flexible bis(benzimidazole) and dicarboxylic acid ligands. Polymer 1 displays a 2D 4-connected 4L2 underlying net topology with the point symbol of (6(5).8) in standard representation. Compound 2 possesses a 2D uninodal 4-connected Shubnikov tetragonal plane net (NO based on a &nuclear Ag-I clusters with the point symbol (4(4).6(2)), which is further extended into a 3D supramolecular framework by pi-pi interactions. Compound 3 possesses dinuclear molecular complex groups, which form chains by weak Ag-O (2.6 A) coordination bonds, and further assembled into a 2D supramolecular layer by hydrogen bonds and pi-pi stacking interactions. These complexes exhibit intense fluorescent emissions in solid state. UV/Vis diffuse reflection spectra and the excellent catalytic activity for the degradation of the congo red azo dye in a Fenton-like process are discussed.