The Construction And Catalytic Properties Study Of Copper Based Metal-Organic Frameworks

Metal-organic frameworks（MOFs）are a class of crystalline porous materials formed by the self-assembly of organic bridging ligands and metal ions,due to their excellent properties such as metal center diversity,organic ligand designability,and pore size controllability,it has become a promising candidate material in the field of heterogeneous catalysis.Cu（I）has excellent properties different from other transition metals,such asπ-coordination activation ability,light absorption,and light conversion ability.Based on the above ideas,the thesis introduced Cu（I）as a metal center into metal-organic frameworks,two examples of Cu（I）-based metal-organic frameworks were constructed,and their applications in the field of heterogeneous catalysis were investigated.The specific research contents of this paper are as follows:（1）A porous framework material Cu-TSP with twisted tetrahedral-coordinated Cu atoms as nodes was constructed by self-assembly of three-armed thiourea-functionalized ligands with Cu⁺.The evenly distributed copper metal centers in the framework structure provide catalytic sites,and multiple hydrogen bonding sites on the thiourea ligands enhance the interaction between framework and reactants,efficient and highly selective catalysis of the cycloaddition reaction of propargylamine and its derivatives with carbon dioxide is achieved through the synergistic effect between theπ-coordination activation of the copper metal center and the hydrogen-bonding sites of the thiourea ligands.In the catalytic cycling experiments,the Cu-TSP can still maintain the stability of the framework structure and can be catalyzed at least five times without obvious loss of catalytic activity.（2）A metal-organic framework material Cu-DNP with Cu₂I₂ clusters as nodes was constructed using two-armed ligands containing 2-hydrazinopyridine molecules and Cu⁺.The crystalline orderly distributed binuclear copper-iodine clusters in the framework structure serve as catalytic sites,combining their photosensitization and organocatalytic functions,the framework material is used as a heterogeneous catalyst to achieve high-efficiency catalysis of azide-alkyne cycloaddition reaction under light conditions,and it can be extended to alkyne reactants with various substituents.In the catalytic cycling experiments,the Cu-DNP framework structure remained intact and could be catalyzed at least five times without significant reduction in catalytic efficiency.