Syntheses,Structures And Applications Of Porphyrinic And Corrolic Porous Framework Materials

Metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)as two new emerging classes of porous crystalline materials,have promising potential applications in many fields of functional materials due to their designable structure,adjustable aperture and tailorable functionality.In this thesis,porphyrin/corrole served as the organic units were assembled into the specific framework materials,which can not only inherit the structural advantages of MOFs/COFs,but also feature the photosensitive and catalytic properties pertaining to porphyrin/corrole,showing the excellent performance in photochemistry and heterogeneous catalysis applications.A porphyrin-based MOF composite photocatalyst TP-222(Zn)was designed and synthesized,containing zirconium-based porph-MOF PCN-222(Zn)linked Ti O₂nanoparticles(NPs)via the compound 4-mercaptopyridine which is axially bonded to the porphyrin central Zn metal in the PCN-222(Zn)and anchored onto the surface of Ti O₂ NPs with the formation of the S–Ti bond.Under visible light irradiation,TP-222(Zn)exhibits the remarkably improved photocatalytic efficiency for degrading organic contaminants.It is powerfully demonstrated by the decreased fluorescence intensity,prolonged fluorescence lifetime,lower interfacial charge-transfer resistance and well-matched energy level that the coordinated introduction of Ti O₂ NPs can promote the electron transfer from PCN-222(Zn)to Ti O₂ with the efficient suppression of electron-hole recombination,and then boost the photocatalytic activity,in which the degradation efficiency reaches 100%and the apparent reaction rate constant of TP-222(Zn)is 2.1 times greater than that of the pristine PCN-222(Zn).A series of corrole-based MOFs(Corrole-MOFs)were successfully constructed for the first time by solvothermal method from the custom-designed 5,10,15-tris(p-carboxylphenyl)corrole(H₃TCPC)as the organic bridging ligand and Zr Cl₄/Hf Cl₄ as the metal source.These framework materials crystallize in the hexagonal space group P6₃/mmc and feature a(3,9)-connected gfy net and 1D open hexagonal mesoporous channels,with the large BET surface area,high porosity and excellent chemical stability.Furthermore,the metal nodes are considered as the unprecedented D_3d-symmetric 9-connected Zr₆/Hf₆ clusters.The prepared cationic Corrole-MOF-1(Fe)from the iron corrole ligand serves as an efficient heterogeneous catalyst for[4+2]hetero-Diels-Alder reactions for the synthesis of dihydropyrans with the excellent catalytic activity,affording 96%conversion outperforming the homogeneous counterpart(67%).The first corrole-based COF(TPAPC-COF)material was developed in which the approximately T-shaped,C_2v-symmetric 5,10,15-tris(p-aminophenyl)corrole(H₃TPAPC)and liner terephthalaldehyde were assembled into the 2D framework with the desymmetrized hcb topology and a staggered AB stacking mode through the imine condensation reaction,exhibiting the high crystallinity,permanent porosity and remarkable chemical stability.The combination of the photoactive property of H₃TPAPC and structural advantages of 2D COFs endows TPAPC-COF with a prominently broad spectral response ranging from the UV to NIR regions.The in vitro photodynamic therapy(PDT)studies demonstrate that TPAPC-COF can efficiently kill cancer cells utilizing the photogenerated singlet oxygen and the cell lethality is 85%,which far surpasses the PDT efficacy(1%)of H₃TPAPC.