Synthesis,Theoretical Calculation,Properties Of Metal Complexes Based On Benzimidazole-5,6-Dicarboxylic Acid Ligand

In recent years,metal complexes have become one of the research hotspots due to their novel structures and great application prospects in the fields of catalysis,magnetism,gas storage,luminescent materials and chemical sensing.In this study,the metal complexes benzimidazole-5,6-dicarboxylic acid(H3bidc),nitrogen-containing organic ligand(2,2'-bipyridine is 2,2-bpy,phenanthroline is phen)and various metal salts(M?Cu2+,Mn2+,Zn2+,Cd2+,Eu3+,Dy3+,Sm3+,Yb3+)were as the ligands or raw materials to synthetize nine metal complexes which were {[Zn(H2bidc)2(H2O)4]·(H2O)4}n(complex 1),{[Eu(H2bidc)(Hbidc)(H2O)3]·3H2O}n(complex 2),{[Sm(H2bidc)(Hbidc)(H2O)3]·3H2O}n(complex 3),{[Dy(H2bidc)(Hbidc)(H2O)3]·3H2O}n(complex 4),{[Yb(H2bidc)(Hbidc)(H2O)3]·3H2O}n(complex 5),{[Cu(Hbidc)(2,2'-bpy)(H2O)]·2H2O}n(complex6),{[Mn(Hbidc)(2,2'-bpy)(H2O)2]·2H2O}n(complex7),[Mn(Hbidc)(2,2'-bpy)(H2O)2]n(complex 8)and{Cd(Hbidc)(phen)[Cd(phen)2Cl2]}n(complex 9)with novel structures and unique functions by hydrothermal and solvent evaporation methods.The above complexes were characterized and analyzed by elemental analysis,infrared spectroscopy,X-ray powder diffraction,crystal structure analysis,thermal stability,solid fluorescence,ultraviolet-visible light properties,and interaction with bovine serum albumin(BSA).What's more,according to the results,the complexes of benzimidazole-5,6-dicarboxylic acid,nitrogen-containing organic ligands(2,2'-bipyridine is 2,2-bpy,phenanthroline is phen)and metal ions were designed.The geometrical structure,electronic structure and bond properties of the complexes were calculated by density functional method.The details are as follows:Complex 1 was synthesized by the hydrothermal methods.The X-ray single crystal diffraction results of the complex showed that it was a small molecular complex.It formed a three-dimensional network structure by hydrogen bondings between the coordination water molecules and the free water molecules.In addition,the complexes were characterized by elemental analysis,infrared spectroscopy,thermal stability and fluorescence properties Based on the experimental results,the Zn(H2bidc)2(H2O)4 molecule was theoretically calculated.The geometry,electronic structure,and bond property of the molecule were investigated by density functional method.When complex 1 interacted with BSA,it could cause static quenching of BSA.The hydrophobic interaction is the main binding force between them.Complexes 2-5 were synthesized by the hydrothermal methods.X-ray single crystal diffraction of complex 2 showed that the complex has one-dimensional ZigZag chain structure.One-dimensional chain structure formed two-dimensional layered structure through the ?…? stacking of benzoimidazole-5,6-dicarboxylic acid and imidazole ring Two-dimensional layered structure formed three-dimensional supramolecular structure through hydrogen bonding between free water molecules and coordinated water molecules At the same time,the above complexes were characterized by elemental analysis,infrared spectroscopy,ultraviolet-visible spectroscopy,thermal stability and fluorescence properties Based on the experimental results,the[Sm(H2bidc)3(H2O)3]·3H2O molecule was theoretically calculated.The geometry,electronic structure,and bond property of the molecule were studied by density functional method.When complex 2 and complex 3 interacted with BSA,it could cause static quenching of BSA.The hydrophobic interaction is the main binding force between themUsing the hydrothermal or solvent evaporation methods,complexes 6-9 were synthesized.The X-ray ray crystal diffraction results of the above complexes indicated that complex 6 had an infinite one-dimensional ZigZag chain structure.The adjacent one-dimensional chain molecular structure formed three-dimensional supramolecular structure by hydrogen bondings between the coordination water molecules,benzimidazole-5,6-dicarboxylic acid and crystalline water molecules.Complex 7 had an infinite one-dimensional zigzag chain structure.The adjacent one-dimensional chain molecular structure formed a three-dimensional supramolecular structure by hydrogen bonding between coordination water molecules,benzimidazole-5,6-dicarboxylic acid and crystalline water molecules.Complex 8 had an one-dimensional ZigZag chain structure,and one-dimensional ZigZag chain structure formed the three-dimensional supramolecular structure through the hydrogen bonding.Complex 9 has one-dimensional chain structure.In addition,XRD,thermal stability,solid fluorescence and ultraviolet-visible properties of the above complexes were tested.According to the experimental results,the Metal(Cu,Mn,Cd)complexes were theoretically build with benzimidazole-5,6-dicarboxylic acid as ligand.The geometry,electronic structure,and bond property of the metal complexes were calculated using density functional method.When complex 6,7 and 9 interacted with BSA,they could cause static quenching of BSA.The Van der Waals force and hydrogen bond interaction are the main binding force between them.