Synthesis,dye Adsorption And Electrochemical Properties Of Coordination Polymers Based On Sulfoaromatic Polycarboxylic Acid

In this thesis,5-sulfo-1,2,4-benzenetricarboxylic acid（H4SBTB）was used as the aromatic carboxylic acid ligand,1,1’-（1,4-butanediyl）dibenzimidazole（BDBM）,1,4Bis（imidazolyl-1-methyl）benzene（BIX）,4,4’-bipyridine（BIPY）as auxiliary ligands,Co（Ⅱ）,Ni（Ⅱ）,Cu（Ⅱ）as metal centers,for the design and synthesis of coordination polymers.Four different coordination polymers were obtained.The structure was analyzed by single crystal diffractometer,and the structure was characterized by infrared,solid ultraviolet,theoretical calculation and thermogravimetric analysis.To explore the dye adsorption and electrochemical properties of coordination polymers,the main work is as follows:1.A new type of coordination polymer,{[Co2（SBTB）（BDBM）2（H2O）]·3H2O}n was synthesized from transition metal Co（Ⅱ）and BDBM,H4SBTB by hydrothermal method at 120℃.Co-BDBM belongs to the monoclinic system,space group P21.In the SBTB ligand,the sulfonate group is monodentate,two carboxylate groups are monodentate,and one carboxylate group（-COO）is bidentate,to bridge two Co（Ⅱ）atoms with a（cis,trans）motif,resulting in the formation of a "Z"-type duplex.These chains are further connected by two crystallographically independent BDBM ligands,resulting in a 2D wave-like layered structure.Hydrogen-bonded water tetramers exist in Co-BDBM,giving rise to the proton-conducting behavior of solid-state and composite Co-BDBM-Nafion films.Interestingly,completely different proton conduction mechanisms are shown:the typical Grotthuss mechanism at pH 3.0 and the Vehicle mechanism at pH 5.0 and 7.0,respectively.Combining the effects of pH,adsorption kinetics and adsorption isotherms,the adsorption capacity of CR by Co-BDBM in aqueous solution was investigated.The results show that the pseudo-second-order kinetic model is in good agreement with the adsorption of CR on Co-BDBM.The Langmuir model fits the adsorption isotherm better than the Freundlich model,indicating that Co-BDBM adsorbs CR in the monolayer mode,and the maximum adsorption capacity for CR reaches a moderate level.Furthermore,the selective adsorption of CR in water by Co-BDBM was demonstrated.2.A new type of coordination polymer {[Ni2（SBTB）（BDBM）2（H2O）]·3H2O}n was synthesized from transition metal Ni（II）and BDBM,H4SBTB by hydrothermal method at 120℃.Ni-BDBM belongs to the monoclinic system,space group P21.The Ni 1 atom is hexacoordinated and exhibits a distorted octahedral configuration,hydrogen bonds are widely present in the lattice,and a discrete water tetramer（O1W,O2W,O3W,and O4W）is formed through the coordination bonds Ni2-O1W and Hydrogen bonds O3W-H3WB…O6（carboxyl groups）are attached to the 2D layer.The interlayer hydrogen bond C29-H29B..Π（3.466 ?:between the C29-bound H29B and the center of the benzene ring C12C13C14C15C16C17）connects the layers into an extended 3D supramolecular structure and further stabilizes the entire network.Due to the existence of hydrogen bonding network in Ni-MOF,it has good proton conductivity.The Ea values of are 0.1563 eV,0.1638 eV,0.2988 eV at pH=3.0,5.0,7.0,respectively,which is consistent with the Grotthuss conduction mechanism.The adsorption capacity of CR on Ni-MOF in aqueous solution was investigated.The results show that the pseudo-second-order kinetic model is in good agreement with the adsorption of CR on Ni-MOF.The Langmuir model fits the adsorption isotherm better than the Freundlich model,indicating that Ni-MOF adsorbs CR in the monolayer mode.The Ni-MOF-MWCNTs glucose enzyme-free sensor was prepared,and the composite material improved the electrochemical activity of the original material and could be used for quantitative detection of glucose.3.Two new coordination polymers[Cu3（SBTB）2（BIPY）3·8H2O]n{[Cu2（SBTB）（BIX）2·H2O]·H2O}n were synthesized from transition metal Cu（Ⅱ）and BIX,BIPY,H4SBTB.Cu-BIPY is a triclinic system with space group P-1.The central metal Cu is in a six-coordinated octahedral configuration,which is interconnected by BIPY and Cu to form a linear single-chain structure,and a three-dimensional structure is formed by double interleaving of BIPY and SBTB.The complex Cu-BIX is a triclinic crystal system,space group P-1,and Cul has a five-coordinate trigonal bipyramid configuration.Cu2 is in a sixcoordination distorted octahedral coordination environment.Each SBTB acts as a six-dentate ligand to bridge three Cu1 and one Cu2,forming a 1D chain structure along the a-axis direction.The connections form a 3D mesh structure.Since Cu-BIPY contains multiple coordinated water molecules,it has good proton conductivity.The Ea values of Cu-BIPY are 0.1105 eV,0.2459 eV,0.2185 eV at pH=3.0,5,0,7.0,respectively,and the Ea values of Cu-BIX at pH=3.0,5.0,7.0 are 0.0814 eV,0.1007 eV,0.2346 eV,consistent with the Grotthuss conduction mechanism.The synergistic effect of the high conductivity of Cu（II）coordination polymers,in 0.1 mol/L sodium hydroxide solution,the detection limit of Cu-BIX is 10.22 μM,and the detection limit of Cu-BIPY is 4.46 μM.Simple non-enzymatic glucose sensor coordination polymer materials offer new opportunities for future development of sensors for scientific research and practical applications.