Synthesis Of Metal-Organic Frameworks (Mils)and Their Properties Of Knoevenagel Condensation Reaction

The new materials development of organic-inorganic hybrid materials is a new area in the composite materials.Its development and application play an important role in our society. MOFs have the properties of organic materials, but also combine the advantages of inorganic materials. Academic circles are concerned about the development of MOFs. MILs materials are a classic representative of the MOFs. MIL-101has large, regular, accessible tunnels and cages.In this paper, metal organic framework MIL-101is synthesized by hydrothermal. MIL-101is functional with N, N-dimethylformamide (DMF), methylamine, ethylenediamine, butylenediamine. X-ray diffraction (XRD), N2adsorption-desorption analysis and infrared spectroscopy (FT-IR) have been employed to characterize the MILs structural features. The catalysts have been functionalized with DMF, methylamine, ethylenediamine, butylenediamine. The results as follows:Metal organic framework MIL-101is synthesized by hydrothermal. We also explore the effect of HF dosage, reaction time and temperature on the yield of MIL-101. The optimal temperature is220℃. The optimal reaction time is8h. The optimal reactant ratios is Cr(NO3)3·9H2O:H2BDC:HF:H2O=1:1:1:265.MIL-101is characterized by XRD,BET and FT-IR prepared in the optimum conditions. The unfunctional MIL-101(Cr) sample gave hardly any conversion in Knoevenagel.The functionalized metal-organic framework materials MIL-101with DMF have high catalytic activity on Knoevenagel condensation.The experiment can be carried out under relatively mild conditions of80℃and the conversion rate reach to93.3%in three hours. The optimum molar ratio of ethyl cyanoacetate and catalyst is7mmol:0.0427mmol. Solvent effect is obvious during the reaction.The functionalized metal-organic framework materials MIL-101with ethylenediamine and butylenediamine have high catalytic activity on Knoevenagel condensation, but the functionalized MIL-101with methylamine do not have high catalytic activity. The mechanism of the condensation reaction is different from the former. The experiment can be carried out under relatively mild conditions of40℃and the conversion rate can be close to100%in three hours. Solvent effect is not obvious during the reaction.