The Construction,Post-synthetic Modification And Functional Regulation Of Metal Organic Framework

Metal-organic frameworks(MOFs)are a class of framework compounds with ordered particular spatial structures that are coordinated and connected by organic ligands through metal or metal cluster cores as nodes.MOFs have attracted widespread attention due to their tunable pore size and diverse structural characteristics.Through analysis of current research status and development trends in the field of metal-organic frameworks,and based on the current research on metal-organic frameworks with specific spatial structures,we attempt to post-synthesize the complexes,including post-synthesis ion replacement and tandem multi-step post-synthesis modification.Post-synthetic substitution mainly involves the cleavage and recombination of a large number of coordination bonds of the complex under crystalline conditions.It has special requirements for the strength of the coordination bonds of the metal-organic framework,frame stability,and reaction conditions.The influencing factors of synthetic ion exchange experiment process and the understanding of its internal mechanism are still in the stage of experimental summary.The current research aims to achieve higher levels of structural property improvement and structural performance improvement.Through the selection of multifunctional ligands,it is possible to construct cluster-spacer,rod-pillar,and pillared-layer MOFs,which process can achieve high stability,large void volume and pore size,and high metal cluster core characteristics.And through the post-synthesis modification,the structure of the gas adsorption,fluorescence,catalysis,and magnetic properties can be adjusted.Based on the accumulated work of our research group in the field of MOFs,we first selects a Linear carboxylate containing a polynitrogen heterocycle,it has diversity coordination mode with carboxylate oxygen atom but also an azolyl nitrogen atoms coordinated in a single way.Extensive exploration and research on new types of specifie straetare MOFs construction and post-synthetic modification,and made some discoveries and progress:1)There shows the synthesis of several new metal-organic frameworks using the polynitrogen heterocyclic linear carboxylate Ligands by solvothermal synthesis:[Mn2(tzba)(CH3COO-)]·2.5DMF(1),[Zn2(tzba)2(DMF)]·1.5DMF(2),[Mn(tzba)(H20)](3),[Fe4(tzba)4]2.5DMF(4),[Zn2(tbdc)(DMF)2(C2H4O3)]·3H2O(5),[Zn4(tbdc)2(DMF)(C2H4O3)2](6)Among them,the disordered arrangement of ligands in the structure of compound 1 were studied in detail.2)An example of a new type metal-organic framework was synthesized by solvothermal synthesis:[Mn3(tzba)3(DMF)4]·6.5DMF·5H2O(7).It has high porosity and framework:flexibility.And through the post-synthesis metal ion exchange,the physical and chemical properties of the sample has be adjustmented.Here we discussed the differences of Cu2+,Co2+,Ni2+,Zn2+and Cd2+in the above construction system;3)An example of two new type with research significance metal-organic frameworks[Zn3(tzba)(Lac)]·4DMF·5 C2H5OH(8),[Zn3(tpdc)(Lac)](9)be synthesized by solvothermal synthesis,which processes gaint Zn22 core,with large void volume,negative framework and high symmetry.The complexes have achieved multi-level,tandem post-synthesis metal ion exchange,and explored the characterization of the complexes with respect to the adsorption of dye molecules.