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polyoxtungstate
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Oxidation of Sulfides and Olefins in the Presence of Nanocluster Polyoxotungstate–intercalated Layered Double Hydroxide Nanoparticles as a Catalyst
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this study, polyoxometalate (POM) intercalated in the layered double hydroxide (LDH) was synthesized by a selective ion-exchange method. For this purpose, the nanocluster [VW12O40]3- was immobilized on the Mg2+/A13+/Cl–LDH support. The heterogeneous catalyst was characterized by FT-IR, XRD, SEM and analysis of ICP. The LDH-POM was applied as a catalyst in efficient oxidation of sulfides to sulfoxides using UHP as oxidant and CH3OH/ CH¬2¬Cl¬2 ¬as a solvent at room temperature, as well as epoxidation of olefins using TBHP as an oxidants and C¬2H4Cl2 as a solvent in 84°C. This catalyst showed excellent catalytic activities for a substrate/catalyst ratio (200:1). For example, this catalytic...
Synthesis of a MOF Supported Polyoxotungstate and its Application as Catalyst in C-C Coupling Reaction
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this study, a polyoxotungestate containing copper was impregnated as catalyst on a magnetic metal-organic framework (Fe3O4/MIL-101(Cr)). Initially, the desired polyoxotungestate was synthesized using sodium tungestate and sodium metasilicate salts and then copper(ІІ) ion was fixed on it. Subsequently, the MIL-101(Cr) metal-organic framework was prepared by solvothermal method; using chromium nitrate salt and 1,4-benzen dicarboxylic acid at 220 ◦C and was magnetized by co-precipitation method. Finally, the corresponding polyoxotungestate was stirred at ambient temperature for 24 h with MIL-101(Cr) and then the brown precipitate was separated using a magnet. Different techniques such as IR,...
Preparation of a Polyoxotungstate-Based Inorganic-Organic Hybrid Catalyst and the Application in Sulfide Oxidation and Azide-Alkyne Cycloaddition Reactions
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this study polyoxotungstate-based inorganic-organic hybrid [C272H162N80Cu16.5W36O129Na9] .80.5H2O was synthesized in situ. This inorganic-organic hybrid resulted from the reaction between copper salt and sodium tungstate with the benzimidazole ligand. Combining inorganic-organic hybrid with polyoxotungstate improved the ability of this catalytic system in oxidation and cycloaddition reactions. The resulting product was identified by IR, X-ray diffraction (XRD), elemental analysis (CHNS), inductively coupled plasma (ICP-OES), field emission scanning electron microscope (FE-SEM) and EDX were technique. The catalyst was used in optimal conditions in sulfide oxidation and azide-alkyne...