Synthesis,structure And Properties Of Coordination Polymers Based On Nitrogen-containing Heterocyclic Carboxylic Acid Ligands

Coordination polymers,also known as metal organic frameworks（MOFs）,are a class of materials with periodically extended structures developed in the last decades.They consist of metal ions or clusters linked by organic ligands,forming a three-dimensional network.Research on MOFs is mainly focused on the following aspects:1)structural composition:to study the coordination bonds between different metal ions and organic ligands;2)structural characterization:to study the structural characterization of MOFs,such as X-ray diffraction,thermogravimetric analysis,etc;3)property characterization:to study the property characterization of MOFs,such as thermal stability,magnetic properties and controllable structures,etc.;4)applications:to study the applications of MOFs in the fields of materials science,chemistry,physics and biology,etc.In this thesis,six coordination compounds were synthesized using a hydrothermal synthesis method based on azomethine carboxylic acid ligands:Co（IMBC）₂（H₂O）₂（1）;Ni（IMBC）₂（H₂O）₂（2）;Cu（IMBC）₂（H₂O）（3）;Cd（IMBC）₂（H₂O）（4）;Ag₃Nd（BIMTA）₃（5）;[Ni（DCBI）（H₂O）₃]·H₂O（6）;In the structures of compounds 1 and 2,metal ions are coordinated with organic ligands to form 1D chain-like structures.Hydrogen bonds,C-H···πandπ···πstacking forces exist between the 1D chains,which eventually form 3D supramolecular network structures.The metal ions in 3and 4 are interconnected with organic ligands to form 2D layered structures,and hydrogen bonding,C-H···πandπ···πstacking interactions connect the 2D layers to form 3D supramolecular structures.The Hirshfeld surface analysis shows that hydrogen bonding,C-H···πandπ···πinteractions are the main interactions between molecules.Compounds 1,2,3 and 4 showed good photocatalytic degradation of organic dyes（MB）.Compounds 1,2,3 and 4 showed good photocatalytic degradation of organic dyes（MB）.Compound 3 showed electrochemical behavior,3 was able to electrocatalytically reduce nitrite ions and bromate ions and was able to electrocatalytically oxidize ascorbic acid.Compound 5 is a three-dimensional Ag-Nd heteronuclear coordination polymer with good antibacterial activity against Gram-negative Escherichia coli,Gram-positive Bacillus subtilis and Gram-positive Staphylococcus aureus,and can be used as a potential solid bacteriostatic agent.Compound 6 is a 1D zigzag chain structure with a 3D supramolecular network structure formed by hydrogen bonding between the 1D chains.6 has the ability to electrocatalytically reduce nitrite and bromate and also to electrocatalytically oxidize ascorbic acid.Meanwhile,6 has the performance of photocatalytic degradation of organic dyes（MB）.