Synthesis And Characterization Of Coordination Compounds Constructed From Flexible Bis(benzimidazole) And Carboxylate Co-ligands

As the important organic–inorganic hybrid materials,coordination polymers(CPs)have attracted much attention by scientists due to their various structures and excellent properties.However,the syntheses of CPs could be influenced by many factors,in which the effects of metal ions and organic ligands are the most remarkable.Thus,it is very crucial to select suitable metal ions and organic ligands to construct CPs.Five flexible bis(benzimidazole)ligands were succeccfully synthesized.And ten novel CPs were obtained under hydrothermally conditions by using these ligands mixed with different carboxylic acids.All CPs were characterizated by elemental analyses,IR and XRPD.In addition,the TGA,solid state UV-Vis spectra,solid fluorescence and catalytic activities for degradation of methyl orange in a Fenton-like process were also investigated.Four new Co(?)-CPs with different structures have been constructed based on diverse aromatic carboxylic acids and 4,4?-bis(benzimidazol-1-ylmethyl)biphenyl(L1).Both compound 1 and 2 are 1D chain structures.Compounds 3 and 4 possess 2D(4,4)and 2D SP 2-periodic net(6,3)Ia topology,respectively.Additionally,compounds 2 and 4 are separately assembled into a 2D and 3D supermolecular network via hydrogen bonds.Six novel metal CPs have been successfully isolated by hydrothermal reactions of various aromatic carboxylic acids and L2~L5 ligands.All of compounds 6,9 and 10 are 2D(4,4)networks,in which 6 and 10 are eventually extended into 3D 3,3,4T3 and 3,3,4T27 supramolecular structures via hydrogen-bond interactions,respectively.Compound 7 shows a 3D two-fold interpenetrating dia network.Compound 8 is a 1D tube-like chain which is furether extended into a 2D supramolecule structure.All the compounds but from 10 demonstate the high thermal stability.Compounds 1~4 display favourable solid UV-Vis properties,and compounds 5,6 and 8 exhibit intense fluorescence properties.Compounds 2,3,4,7 and 10 manifest excellent catalytic activities in a Fenton-like process,which could be used as potential catalytic materials.