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Immobilized Manganese-porphyrin and Molybdenum-Schiff Base Complexes on Functionalized Magnetic Nanoparticles as Efficient Recyclable Nanocatalysts in Hydrocarbon and Sulfide Oxidation Reactions
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this thesis, functionalized Fe3O4 nanoparticles have been utilized as a support for immobilization of homogeneous catalysts. The catalytic activity of the supported heterogeneous nanocatalysts was investigated in hydrocarbon and sulfide oxidation reactions. In the first part of this research, imidazole functionalized Fe3O4 nanoparticles (Fe3O4@SiO2-Im) were used as a support to anchor manganese porphyrin complex, [MnT(4-OMeP)P]OAc; via axial ligation. Catalytic application of the immobilized manganese porphyrin was studied in oxidation of alkenes and sulfides. To find suitable reaction conditions, the effect of different parameters such as solvent and temperature on immobilization process...
Synthesis, Characterization and Modeling of Active Sites in Dinuclear Metalloenzymes
, Ph.D. Dissertation Sharif University of Technology ; Mohammadi Boghaei, Davar (Supervisor)
Abstract
In order to have more understanding of the cooperative effect between the metal centers in the multimetallic complexes, on their physicochemical properties and chemical reactivity, some new bi- and tetra-nuclear Cu(II), Ni(II) and Pd(II) complexes of compartmental binucleating ligands were synthesized and characterized. In this study, a series of new compartmental binucleating thiophenol-based proligands PL1-PL4 from the Schiff base condensation of 2 equiv. of o-aminophenol or 2-amino-4-methylphenol with 1 equiv. of 2,6-diformyl-4-alkyl- thiocarbamoyl were synthesized and characterized. New Bi- and tetra-nuclear copper (II) complexes derived from these binucleating compartmental...
The stereoselective synthesis of the tetrahydrothiopyranolr ,Y'-blindole skeletons via tandem reaction of indoline- r-thiones to Baylis-Hillman adduct acetates & Silica-Supported DABCO-tribromide: A New, Versatile and Recyclable Catalyst for the Chemoselective Oxidation of Sulfides to Sulfoxides and Oxidative Coupling of Thiols into Disulfides
,
M.Sc. Thesis
Sharif University of Technology
;
Matloubi Moghaddam, Firouz
(Supervisor)
Abstract
We have reported a new and efficient synthesis of tetrahydrothiopyrano [2,3-b]indole skeletons via unique tandem reaction of indoline-2-thiones to Baylis-Hillman adduct acetates. This protocol is a very mild and simple method for construction heterocycles in a one-step process. This is a convenient and diastereoselective synthesis of methyl 4-aryl-2,3,4,9-tetrahydrothiopyrano[2,3-b]indole-3-carboxylate systems in the presence of K2CO3 in acetonitrile. The major benefits of the current study are the one-pot procedure, high yields and diastereoselectivity, short reaction times and the similarity of the products to the biologically active moieties.
In addition 1, 4-diazabicyclo [2.2.2]...
In addition 1, 4-diazabicyclo [2.2.2]...
Synthesis of Mo-Complex with An Ionic Salen Ligand and Its Application in Catalytic Epoxidation of Olefins and Sulfide Oxidation
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this project synthesis and characterization of a novel dioxomolybdenum(VI), with tetradentates Schiff base ligand which was soluble in water. The first step of complex synthesis was chloromethylation of salicylaldehyde and the second step was the reaction with the pyridine. After that salen ligand will be synthesized by reaction with ethylene diamine. In the presence of Mo(acac)₂(VI) the final product will be synthesized. The complex was characterized by spectroscopic methods such as UV, NMR, FT-IR and CHN. The synthetized complex was studied for olefin (aliphatic and aromatic) epoxidation as well as sulfide oxidation. It was more active in aliphatic olefins epoxidation than sulfide...
Synthesis of Core-Shell Nanoparticles Supported Iron and Vanadium Schiff Base and Their Application as a Catalyst for Oxidation of Sulfides, Alcohols and Olefins
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this work, synthesized Fe3O4 magnetic nanoparticles andcoated with SiO2 to prepare magnetic core-shell nanoparticles. Then immobilized Schiff baseof iron and vanadium complexes on magnetic core-shell nanoparticles was prepared as a recoverable magnetic nano catalysts. These catalysts were named Fe3O4@SiO2@L1@Fe, Fe3O4@SiO2@L2@Fe and Fe3O4@SiO2@L3@V. Furthermore,olefines epoxidation, sulfides and alcohols oxidation were studied with using iron and vanadium magnetic nano catalysts. The supported catalysts were characterized by atomic absorption, FT-IR and UV–Vis spectra.The catalytic performance of the synthesized iron catalyst was tested for the epoxidation of cyclohexene, styrene and...
Synthesis and Characterization of Vanadium (IV)-SNO & ONO Tridentate Schiff-Base Complexes and Their Applications in Sulfide and Alcohol Oxidation in Ionic Liquid Media
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In recent years, application of transition metal biphasic catalytic systems for different reactions is an area of intense research activity. Among these reactions, oxidation of sulfides to sulfoxides and sulfones due to their importance as an intermediate in synthesis of organic compounds is a center of interest. Also, the catalytic conversion of alcohols to the corresponding aldehydes or ketones is a fundamental transformation in both laboratory and industrial synthetic chemistry. From environmental perspectives, the development of new catalytic oxidation systems with molecular oxygen as green oxidant is particularly attractive. In recent years, ionic liquids have been extensively studied...
Formulation and Prodution of Organometal-halide Provskite Cells to Increase Solar Cells Efficieny
, M.Sc. Thesis Sharif University of Technology ; Nemati, Ali (Supervisor)
Abstract
Today organometallic perovskites are very important in fabrication of solar cells. This materials have advantages like high mobility of charge carriers, changing in range of light aborption with changing in structures atoms, having longer charge carrier diffusion lengths than other materials, high stability and efficiency, Low-cost fabrication process, having capability of studying and processing in low temperatures and having flexibility because of Weak chemical bond in perovskite structure. Due to the low stability and rapid decomposition of this material with the presence of light and moisture, in this study has tried to use PbS quantum dots which is used in sensitive dye solar cells as...
Investigation the Effect of Formamidinium Lead Halide on the Stability and Performance of Graphene Phototransistors Based on Lead Sulfide
, Ph.D. Dissertation Sharif University of Technology ; Simchi, Abdolreza (Supervisor)
Abstract
Enhancing the detection range, sensitivity and stability of phototdetectors due to their vast applications are in great importance. In recent years, Lead sulfide quantum dots, in order to their absorption over a wide range of wavelengths including Near-infrared (NIR), multiple exciton generation effect and solution processability are promising materials.However, long organic surface ligands which are necessary in synthesis process can suppress the carrie transport and the common method to overcome this weakness, is ligand exchange process. In this way, using short organic ligands because of their low electron mobility and methylammonium lead iodide ligands in order to their instability,...
Preparation of Magnetically Recyclable Silica Supported Oxovanadium Nanocatalyst and its Application in the Oxidation of Sulfides
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
Current study reports a state-of-the-art approach for synthesis of nanocatalyst based on Oxo-vanadium Schiff base complex which itself is, covalently, immobilized on core-shell magnetic nanoparticles of silica-modified magnetite (Fe3O4@SiO2) and the substantial potential it offers as heterogeneous catalyst in selective oxidation of sulfides.Synthesized materials and complexes in this project were characterized by means of modern spectral devices such as FT-IR, XRD and SEM.Unlike routine process of the preparation of heterogeneous catalysts that requires further modification of the core-shell nanoparticles with capping agents, here we have been capable of cutting some time-consuming steps...
Molybdenum liquid salts immobilized on ionic liquid-modified silica as efficient heterogeneous catalysts for sulfoxide reduction
, Article Tetrahedron Letters ; Volume 54, Issue 29 , 2013 , Pages 3765-3768 ; 00404039 (ISSN) ; Ghazali Esfahani, S ; Sharif University of Technology
2013
Abstract
Two room temperature liquid salts containing molybdenum(VI), [BMIM] 2[MoO2(NCS)4] (1) and [DMIM] 2[MoO2(NCS)4] (2), were immobilized on ionic liquid-modified silica leading to materials which showed notable catalytic activity for the reduction of sulfoxides into sulfides with triphenylphosphine (PPh3). The molybdenum liquid salts immobilized on the supported ionic liquid phase could be reused at least for three catalytic cycles without significant loss of activity
Near-white emitting QD-LED based on hydrophilic CdS nanocrystals
, Article Journal of Luminescence ; Volume 132, Issue 2 , 2012 , Pages 467-473 ; 00222313 (ISSN) ; Marandi, M ; Saievar Iranizad, E ; Taghavinia, N ; Liu, B ; Sun, H. D ; Sun, X. W ; Sharif University of Technology
Abstract
In this work we report fabrication of a nanocrystal (NC)-based hybrid organicinorganic LED with structure of ITO/PEDOT:PSS/PVK/CdS-NCs/(Al or Mg:Ag). The hydrophilic CdS NCs were synthesized using a novel aqueous thermochemical method at 80 °C and sizes (around 2 nm) were controlled by thioglycolic acid (TGA) as the capping agent. The favorite feature of these NCs is their relatively high emission intensity and broad, near-white emission. The hydrophilic CdS NCs were successfully spin coated using Triton X-100 as the wetting agent. The fabricated LEDs demonstrated a turn on voltage about 7 V for Al metallic contact. The electroluminescence was a broad spectrum at 540 and 170 nm width, which...
Desulfurization of liquid-phase Butane by zeolite molecular sieve 13X in a fixed bed: Modeling, simulation, and comparison with commercial-scale plant data
, Article Energy and Fuels ; Volume 22, Issue 1 , 2008 , Pages 570-575 ; 08870624 (ISSN) ; Molaei Dehkordi, A ; Goodarznia, I ; Sharif University of Technology
2008
Abstract
This paper deals with the modeling and simulation of binary liquid-phase adsorption of methyl mercaptan and hydrogen sulfide from a liquid butane stream by zeolite molecular sieve 13X in a fixed bed. The model equations account for the effect of axial dispersion and the inter- and intraparticle, mass-transfer resistances at isothermal operating conditions. Orthogonal collocation and Gill's fourth-order Runge-Kutta methods were used to solve the dimensionless general forms of the 4N-eoupled ordinary differential equations for simultaneous adsorption of the solutes by the adsorbent in a fixed bed. The model predictions were compared to the commercial-scale plant data of an Iranian...
Influence of process variables on biooxidation of ferrous sulfate by an indigenous Acidithiobacillus ferrooxidans. Part II: Bioreactor experiments
, Article Fuel ; Volume 86, Issue 7-8 , 2007 , Pages 993-999 ; 00162361 (ISSN) ; Yaghmaei, S ; Jafari, A ; Sharif University of Technology
2007
Abstract
The oxidation of ferrous iron in solution using Acidithiobacillus ferrooxidans has industrial applications in the regeneration of ferric iron as an oxidant agent for the removal of hydrogen sulfide from waste gases, desulphurization of coal, leaching of non-ferrous metallic sulfides and treatment of acid mine drainage. The aim of this attempt was to increase the biooxidation rate of ferrous sulfate by using immobilized cells. Rate of ferrous iron oxidation was determined in a packed-bed reactor configuration with low density polyethylene (LDPE) particles as support material in order to find the most practical system for scale-up. The present work studies the influence of basic parameters on...
Zinc extraction from Iranian low-grade complex zinc-lead ore by two native microorganisms: Acidithiobacillus ferrooxidans and Sulfobacillus
, Article International Journal of Mineral Processing ; Volume 80, Issue 2-4 , 2006 , Pages 238-243 ; 03017516 (ISSN) ; Yaghmaei, S ; Vossoughi, M ; Jafari, A ; Roostaazad, R ; Sharif University of Technology
2006
Abstract
A mesophilic iron oxidizing bacterium, Acidithiobacillus ferrooxidans, has been isolated (33 °C) from a typical, chalcopyrite concentrate of the Sarcheshmeh copper mine in the region of Kerman located in the south of Iran. In addition, a thermophilic iron oxidizing bacterium, Sulfobacillus, has been isolated (60 °C) from the sphalerite concentrate of Kooshk lead and zinc mine near the city of Yazd in the center point of Iran. Variation of pH, ferrous and ferric concentration on time and effects of some factors such as temperature, cell growth, initial ferrous concentration and pH on bioleaching of low-grade complex zinc-lead ore were investigated. The results obtained from bioleaching...
Fine tuning of the size of CdS nanoparticles synthesized by a photochemical method
, Article Nanotechnology ; Volume 17, Issue 5 , 2006 , Pages 1230-1235 ; 09574484 (ISSN) ; Taghavinia, N ; Iraji zad, A ; Mahdavi, S. M ; Sharif University of Technology
2006
Abstract
In this work, we propose a combined photochemical-chemical method that enables us to grow CdS nanoparticles with ångström precision. CdS nanoparticles were formed through a photo-induced reaction between CdSO 4 and Na2S2O3. Thioglycerol (C 3H8O2S) was used as the capping agent. Fine tuning of the size was subsequently carried out by controlling the pH of the solution. Optical absorption spectroscopy was mainly used to monitor the process of particle formation, and to measure the bandgap and size. X-ray diffraction spectra confirmed the optical sizes and demonstrated crystalline nanoparticles. In the presence of the capping agent there was a dark growth that was completely dependent on the pH...
Importance of N-P-N junction in H2S sensing process of SnO2-CuO heterostructures: A theoretical macroscopic approach
, Article IEEE Sensors Journal ; Volume 21, Issue 6 , 2021 , Pages 7123-7129 ; 1530437X (ISSN) ; Ghorbani, M ; Mohammadpour, R ; Moosavi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Metal-oxide gas sensors are widely used for detection of detrimental H2S gas. Among them, SnO2-CuO system has been proved to be an excellent candidate. The previous theoretical 2D thin bilayer model was able to explain some aspects of H2S sensing performance of this promising system. However, experimental researches have indicated that response values for this system are very diverse and various SnO2-CuO multicomponent heterostructures such as rods, wires and particles have much higher response than their thin bilayer counterparts. Understanding the reason behind this differences would help fabrication of optimized sensor element. However, the previous model cannot address this issue mainly...
Design, manufacture and application of a microreactor for the decomposition of ethyl mercaptan on an H-ZSM-5 catalyst
, Article Journal of Cleaner Production ; Volume 292 , 2021 ; 09596526 (ISSN) ; Kazemeini, M ; Mohammadi, A ; Rashidi, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Catalytic decomposition of the ethyl mercaptan over an H-ZSM-5 zeolite in a newly designed microreactor was undertaken in this study. A numerically developed distributor possessing superior flow distribution was amended to 24 parallel microchannels with 64 mm length, 700 μm width, and 600 μm depth. Ethyl mercaptan complete conversion required 350 °C through the developed microreactor while in a conventional fixed-bed-reactor 400 °C was needed. Higher selectivity towards the main products of this decomposition (hydrogen sulfide and ethylene) were observed in this microreactor in comparison to that of a fixed-bed-reactor. In addition, lower selectivity towards formation of byproducts was...
The effect of target annealing temperature on optical and structural properties and composition of CdS thin films prepared by pulsed laser
, Article Optical Materials ; Volume 27, Issue 10 , 2005 , Pages 1583-1586 ; 09253467 (ISSN) ; Iraji Zad, A ; Tilaki, R. M ; Sharif University of Technology
Elsevier
2005
Abstract
We studied the effect of target annealing temperature on optical and structural properties and composition of CdS thin films prepared by pulsed Nd:YAG laser. Deposited samples from annealed targets at 300 °C showed a mixed cubic and hexagonal structure, a band gap of about 2.56 eV and Cd/S ratio equal 1. This ratio increased to 2.40 and its band gap decreased to 2.46 eV when the sample was annealed at 500 °C for 1 h in air. However, films prepared from annealed targets at 500 °C became dark due to existence of polymorphous phase of CdO. Films changed to transparent yellow color with a hexagonal CdS structure and some peaks related to CdO after annealing above 250 °C in air. Its band gap...
Photo-induced CdS nanoparticles growth
, Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 30, Issue 1-2 , 2005 , Pages 114-119 ; 13869477 (ISSN) ; Azam Iraji Zad ; Mahdavi, S. M ; Reza-Esmaili, M ; Sharif University of Technology
2005
Abstract
A photochemical approach on the size control of CdS nanoparticles is presented. CdS nanoparticles were grown using the photo-induced reaction of sodium thiosulfate with Cadmium sulfate, in the absence of any surfactant. Particles of 5.5-11 nm were obtained by changing the illumination time. The dark growth of nanoparticles was negligible, however we found by optical scattering measurements that a ripening phenomenon occurs and the size of nanoparticles slightly increases with time. © 2005 Elsevier B.V. All rights reserved
The separation of cadmium from zinc with a synergistic mixture of nonylsalicylic acid and triisobutylphosphine sulphide
, Article Hydrometallurgy ; Volume 78, Issue 1-2 SPEC. ISS , 2005 , Pages 129-136 ; 0304386X (ISSN) ; Urbani, M ; Cheng, C. Y ; Askari, M ; Bastani, D ; Sharif University of Technology
2005
Abstract
Metal pH50 and ΔpH50 values were determined and compared for a number of organic systems to select a synergistic system for the separation of Cd from Zn. The largest ΔpH50(Zn-Cd) value was obtained with HRJ-4277 (nonylsalicylic acid)/Cyanex 471X (triisobutyl phosphine sulphide or TIBPS) system and reached 1.53 pH units, indicating excellent separation of Cd from Zn with this system. Shellsol 2046 was chosen as the diluent of the system due to its larger ΔpH50(Zn-Cd) and excellent phase separation compared with other diluents. Distribution isotherms and subsequent McCabe-Thiele diagrams indicate that 99% Cd could be extracted in two stages at pH 3.80 and A / O ratio of 1.5 : 1. The extraction...