MOFs With Pd Metal Ligand For Suzuki Catalytic

Metal-organic frameworks(MOFs) are constructed by joining metal ions or metal clusters with organic units using coordination bonds to create novel porous materials. They possess high specific surface area, porosity and chemical tunability, for which they could be used as an efficient catalyst in sulfide oxidization, C-C coupling, oxidation and reduction of olefin. Organic ligands with active centers for building functional MOFs has attracted much attention, since they can efficiently catalyzing substrates.Pd metalloligand formed by isonicotinic derivatives with Pd(Ⅱ), could be used as dicaboxylate bridging ligands. The carboxylic groups coordinated with metal ions were to build functional MOF materials—Pd(Ⅱ)/Zr-MOF and Pd(Ⅱ)/Cu-MOF, which were achieved by changing reaction conditions(temperature, time, solvent) by solvothermal synthesis. The structure and morphology of synthesized MOFs materials were characterized by powder X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, FT-IR. The results proved that carboxylic groups of Pd metalloligand were incooperated with metal ions, and Pd with a high degree of dispersion was divalent in the MOF network,and Pd(Ⅱ) unevenly dispersed in the MOF network.Palladium catalyed Suzuki-Miyaura couplings as common organometallic reactions, have become classic methods for generating carbon-carbon bonds. However, palladium catalysts are difficultly recovered and display relatively poor activity due to the low dispersion of Pd(Ⅱ) active sites. In this work, Pd(Ⅱ)/Zr-MOF containing highly dispersed palladium active centers was synthesized successfully using Pd metalloligand as building units. In Suzuki-Miyaura coupling reaction, Pd(Ⅱ)/Zr-MOF exhibits the efficient catalytic activity and yields up to 99%, because dispersed Pd(Ⅱ) as catalytic active center could activate the substrates.