چكيده به لاتين
In the present work two previously reported MOFs named MIL-101 and MIL-101-NH2 (amine functionalized MIL-101) were synthesized from Cr(NO3)3•9H2O and benzene-1,4-dicarboxylic acid and 2-aminobenzene-1,4-dicarboxylic acid through hydrothermal condition. Monometallic Cu3(BTC)2 was synthesized from Cu(NO3)2•3H2Oand benzene-1,3,5-tricarboxylic acid through hydrothermal condition and bimetallic Cu3-yCoy(BTC)2 was synthesized from Cu(NO3)2•3H2Oand Co(NO3)2•6H2O and benzene-1,3,5-tricarboxylic acid through hydrothermal and microwave methods. In this work, two goals were followed: first of all, In order to evaluate the catalytic activity of MIL-101 and MIL-101-NH2 in the one-pot three-component synthesis of 2,4,5-trisubstituted imidazoles, We used benzil, various substituted aromatic aldehydes and ammonium acetate in the presence of these MOFs which acted as efficient and recoverable catalysts. the advantages of using the mentioned MOFs as heterogenous catalysts in these reactions were short reaction time, high yield, easy and quick isolation of the catalysts and the products, low amount of catalysts needed and solvent free conditions. The structure of the MOFs was confirmed by field emission scanning electron microscopy (FE-SEM) and X-ray diffractometer (XRD). Fourier-transform infrared spectroscopy (FT-IR) and Proton nuclear magnetic resonance (H-NMR) were performed for the confirmation of the synthesized products.
Second, the UV-VIS spectroscopy was performed on mono- and bimetallic MOFs. We observed that the band gap for monometallic Cu3(BTC)2 was about 3.6 eV while for its bimetallic Cu3-yCoy(BTC)2 MOF reduced to 3.4 eV. In order to obtain a conductive MOF and to study the structural and electrical behaviour of these MOFs, their composite with graphene functionalized with amine groups and graphene functionalized with carboxylic acid groups were synthesized. Their structure was confirmed by field emission scanning electron microscopy (FE-SEM) and X-ray diffractometer (XRD) and energy dispersive X-ray spectroscopy (EDX). The 4-probe method was used for conductivity measurement of the synthesized composites.
