Synthesis Of Zeolite Imidazolate Frameworks Mateuial And Used As An Efficient Heterogeneous Catalyst For Various Chemical Reactions

The porous material is a significant segment of the economy, it is in general consideration to develop and design porous material to have versatile properties such as well-defined structure, tunable pore size, high porosity and highly thermal and chemical stability to perform different type of commercial and industrial applications. For last couple of decades, there is lot of effects has been done to discover and explore new porous materials. Metal organic frameworks (MOFs) materials attained much more interest due to their extraordinary structures and properties with their capability for different applications. In his research work, we selected Zeolite Imidazole Frameworks (ZIFs) materials which possess crystal structure like zeolite materials, is a type of MOFs materials. We focused on the synthesis of ZIF-67, heteropoly acid encapsulated into ZIF-67cage and ZIF-8materials and give their applications in the Friedel-Crafts acylation reactions as an efficient heterogeneous catalyst.Initially, this work demonstrated the synthesis of ZIF-67materials which containing cobalt as metal ions and2-methylimidazole as ligand, triethylamine is used as deprotonated the ligand. ZIF-67is synthesized with different metal:ligand:TEA molar ratios along with metal:ligand ratio at room temperature. Various characterization techniques are utilized such as X-ray powder diffraction abbreviated as XRD, Fourier transform infrared spectroscopy abbreviated as FT-IR, Scanning electron microscopy abbreviated as SEM, Nitrogen adsorption-desorption as well as Thermo-gravimetric analysis (TGA) to explore the characteristics of synthesized ZIF-67samples. The catalytic performance of synthesized ZIF-67is investigated in Friedel-Crafts (FC) acylation reaction of anisole by means of benzoyl chloride as acylating agent. The performance of ZIF-67(metal:ligand molar ratio1:8) sample as catalyst is found better as compare to other ZIF-67samples which involve TEA as deprotonated the ligand.45%conversion is achieved in the company of10wt%of ZIF-67(metal:ligand molar ratio1:8) exclusion of any inert atmosphere. ZIF-67(metal:ligand molar ratio1:8) can be isolate from the organic phase, reuse without considerable loss in catalytic performance.Later on, a novel stratagem for the encapsulation of heteropoly acid inside Zeolite imidazolate framework (ZIF-67) cage has been utilized involving the supplement of heteropoly acid in the synthesis mixture of ZIF-67. Phosphotungstic acid (H3PW12O40denoted as PTA) is used for encapsulation into the ZIF cage. Different techniques, Element analysis abbreviated as ICP-AES, X-ray powder diffraction abbreviated as XRD, scanning electron microscopy abbreviated as SEM and Fourier transform infrared spectroscopy abbreviated as FT-IR has been employed for the bare ZIF-67and PTA@ZIF-67encapsuia!ed catalysts characterization. These all techniques confirmed that14.5-31.5wt%PTA is encapsulated and retained as ZIF-67structure. The catalytic performance of bare ZIF-67and the novel composite materials PTA@ZIF-67encapsulated have been investigated in Friedel-Craft (FC) acylation reaction of anisole by mean of benzoyl chloride as acylating agent. The catalytic performance of26.5wt%PTA@ZIF-67encapsuiated is found predominant to the bare ZIF-67and other PTA@ZIF-67encapsu!ated catalysts. High conversions are accomplished in the presence of26.5wt%PTA@ZIF-67encapsuiated catalyst (2-10wt%) without need for an inert atmosphere, selectivity of the p-isomer is achieved about93-95%. PTA@ZIF-67encapsulated is found stable to PTA leaching, can be isolate from the organic phase and reuse without considerable loss in catalytic performance.Finally, we direct our research work on synthesis of ZIF-8material which involves the zinc as metal ion and2-methylimidazole as ligand. The synthesis of ZIF-8has been done at room temperature. X-ray powder diffraction abbreviated as XRD, Fourier transform infrared spectroscopy abbreviated as FT-IR, Scanning electron microscopy abbreviated as SEM and Nitrogen adsorption-desorption characterization techniques are utilized to explore the synthesized ZIF-8structural properties. The catalytic performance of ZIF-8has been assessed by conducting Friedel-Crafts (FC) acylation reaction of toluene by mean of acetyl chloride as acylating agent. High conversion is recorded in company of ZIF-8without need of an inert atmosphere. ZIF-8can easily separate from the organic phase of reaction and reused in reaction.