Synthesis of new nano metal-organic frameworks with urea and thiourea ligands and investigation of their application in sensing, catalysis and removal of hazardous materials

Metal-Organic Frameworks (MOFs) are a new category of porous materials that have been extensively used in various applications due to their unique properties such as crystallinity, high surface area, designability, favorable thermal and chemical stability, and so on. In this dissertation, new metal-organic frameworks were designed and synthesized by applying new ligands with different functional groups (Amide, Malonamide, Sulfonyl and Urea) to achieve useful structures as catalyst, adsorbent, and sensing probe. The structures which were characterized by single crystal X-ray crystallography, PXRD, TGA, SEM, and BET are the following: TMU-49,50,51 and TMU-49S,50S,51S ; TMU-81, PTMU-81, MC-81; TMU-32,32S ; TMU-46,47,48 and TMU-46S,47S,48S; TMU-67,68. TMU-49,50,51 and TMU-49S,50S,51S which were functionalized with amide and malonamide moieties respectively revealed high catalytic performance in the ring-opening reaction of epoxides based on their ability to form multiple effective interactions with epoxides. Three new structures (TMU-81, PTMU-81, MC-81) were designed by different strategies (functionalized MOF and MOF derived carbon and metal carbon structures), with the aim of developing a high-yield and sustainable template for the Ullmann reaction. TMU-81 which contains sulfonyl and amide groups used for the removal of Cd(II), Cu(II), and Cr(II) ions from simulated aqueous solutions. Also, at the end metal-containing structures were recovered and pyrolyzed in argon gas flow in order to achieve metal-carbon hybrids. TMU-32 and TMU-32S series which contain hydrophilic urea-malonamide, has been designed and studied for the detection and removal of mercury ions. The framework and the modified derivatives show rapid, effective, and selective adsorption toward Hg(II). TMU-46,47,48 and TMU-46S,47S,48S with amide and malonamide functional groups used for heavy metal ions detection and TMU-48S display high efficiency for detection of Hg(II) in the presence of other metal cations such as Cu(II) and Cd(II) ions. Three amide-based MOFs TMU-46, 47 and 48 synthesized under ultrasound reaction and also using different capping materials and the florescence properties of these nano size structures towards nitroaromatic explosives have been investigated. Two novel zinc MOFs namely TMU-67 and TMU-68 with dicarboxylate/urea-containing pyridyl ligands synthesized and their recognition ability towards different oxo and halide anions in water have been assessed.

Publication year:2022

Keywords:Doctoral thesis

Accessibility:Open