Design And Construction Of Thiourea-Based Cu/Ag Metal-Organic Frameworks And Their Properties

Metal-organic framework(MOFs),as a kind of crystalline in organic-organic hybrid materials,have tunable pores,large surface area,and high porosity.Group IB metal Cu and Ag have special nature compared with other transition metals,such as Ag-? interaction and photosensitization.In this thesis,we incorporated Cu/Ag clusters into metal-organic frameworks and constructed a series of Cu/Ag-based MOF materials.This thesis has three parts,which focus on gas separation,catalysis,and photocatalysis,respectively.In the first part,we reported a new method to construct porous thiourea-based metal-organic frameworks AGTU-3,in which the ligands contained thiourea groups.By taking advantage of the deprotonation of thiourea-based ligands,the cationic frameworks can be transformed into neutral frameworks(AGTU-3a)and anions in pores can be easily removed without the strong Coulomb interaction through treating with triethylamine under mild conditions.With the planar coordination geometry of open Ag(?)sites and?-complexation of Ag(?)-olefin interactions,AGTU-3a shows good performance in the separation of propene/propane mixtures.This work would provide a new route to construct open Ag(?)sites in MOFs.In the second part,two new silver-cluster-based frameworks were synthesized by incorporating thiourea on the backbone of the tripodal ligan ds.Given th e large ligands and appropriate coordination geometries,these h eterogeneous materials had large pore sizes and high density of catalytic sites,and could be used as high-efficiency ?-activation reaction catalysts in the atom-economical cycloaddition of propargylamines with carbon dioxide.The loading of 0.1 mol%catalysts enabled the almost complete transformation of the propargylamines into oxazolidinones at atmospheric pressure and room temperature,the turnover number was about TON=930,which represented the highest TON value compared with the cycloaddition catalysts of propargylamines.Raman/IR spectra and X-ray crystallinity structure of substrates-encapsulated crystal further confirmed the Ag-?interaction and hydrogen bonding interaction between propargylamines and Ag clusters.In the third part,a cuprous cluster-based framework CCM-1 was synthesized by incorporating photoactive Cu4S6I4 clusters as nodes.The photo-excited cuprous clusters can reduce the reactant and produce radical hydrocarbon,and catalyze the C-N coupling reaction.The cuprous clusters can play double roles in photocatalysis:photoactivation and catalysis.The crystalline and separated cuprous clusters in the framework can avoid the self-quenching of photocatalysts and shorten reaction steps.The photocatalyst CCM-1 can be applied in C-N coupling reactions with various alkane/aromatic halide or carboxyl reactant and high stereoselective photocatalytic C-N coupling reactions.