| MOFs material is a kind of new solid state crystal material with periodic and infinite network topology formed by the coordination between the metal centers and organic ligands through self-assembly process.MOFs material has great potential in the field of heterogeneous catalysis owing to their adjustable pore size,high activity and recoverability.Accompanyingthedevelopmentofadvanced characterization technologies and multi-disciplinary cooperation research,the framework structures and functions of MOF materials have been reached to the domain of systematic control and rational modification by in situ self-assembly or post-modification.Here in two MOFs heterogeneous catalysts have been designed and synthesized,Pd?II?/Zn-MOFandPd?II?-bpc@IRMOF-3,and characterized by the powder X-ray diffraction,EDS,X-ray photoelectron spectroscopy,infrared spectra and so on.The results shows that metal ion substitution has been occurred during the synthesis of Pd?II?/Zn-MOF by precursors,andtheproposedmolecularcompositionis[Zn0.25Pd0.75?NH2-BDC?0.6?BPC?0.8].By the post modification synthesis process,the supported catalyst Pd?II?-bpc@IRMOF-3 has been successfullyprepared,withtheproposedcompositionof[Zn4O(BDC-(NH-CO-C10H7N2))0.6?NH2-BDC?2.4?Pd?CF3COO?2?0.6].Thermogravimetric analysis studies shows that both of the two catalysts are thermal stable,with the decomposed temperature of 270°C and 200°C respectively,which is meeting the need of the most of the catalyst reactions.The catalytic properties of the two MOFs have been discussed,and both of them exhibit good catalytic effect in the conjugate addition of arylboronic acid to?,?-unsaturated ketones.The optimum catalytic conditions have been obtained using the screening reactions,and the hightest yield is 99%.The hot filtration test proves that both catalysts are heterogeneous catalysts.Cyclical experiments shows that the recovered Pd?II?/Zn-MOF catalyst retains excellent efficiency after three reaction cycles. |
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