Chelating Metal Ions in a Metal-Organic Framework for Constructing a Biomimetic Catalyst Through Post-modification

Crystal engineering,as a burgeoning technology,has been widely used to construct metalloporphyrins biomimetic catalysts.Herein,a bimetallic metal-organic framework(MOF)was constructed by 4-(4-carboxyphenyl)-1,2,4-triazole ligand,Co2+and Zr4+metal ions by solvothermal reaction(named PFC-88).A N,N-chelation site was found between the two adjacent ligands in PFC-88,consequently a porphyrin-like structure was obtained through chelating Fe3+in this site by post-modification,named PFC-88-Fe.The result of a single crystal X-ray technology verified that Fe ions were successfully metalated in the N,N-chelation site of PFC-88,which is assisted by the X-ray absorption near-edge structure(XANES)spectra.An o-phenylenediamine oxidation reaction was applied to assessing the catalytic activity of PFC-88-Fe,in which the absorbance increases of phenazine-2,3-diamine atλ=418 nm were recorded by absorption spectroscopy in kinetic mode,exhibiting the application potential as a biomimetic catalyst.