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    Synthesis of Dithiocarbamate Salts, Reaction of Divinyl Sulfone with Amines and CS2 & Polymerization of Diamines and CS2 with Michael Acceptors

    , M.Sc. Thesis Sharif University of Technology Raesi, Mozhgan (Author) ; Mahmoodi Hashemi, Mohammad (Supervisor) ; Ziyaei Halimjani, Azim (Supervisor)
    Abstract
    At the first part of project, different kinds of monodithiocarbamates were synthesized.In order to prepare these compounds two methods have been used:Reactions of amines and carbon disulfide in water and finally addition of Michael acceptors.Reaction of amines and carbon disulfide, then addition of alkyl halides under solvent-free conditions.Dithiocarbamate salts are prepared in ether by using CF3SO3CH3 as the methylation agent with resulted monodithiocarbamates at the first part of the project. These salts are found to be ionic liquids, which is important class of organic compounds.At the second part of project, the Michael additions of amines with divinyl sulfone are investigated in... 

    Michael Addition of Aromatic Amines and Synthesis Some Derivatives of Thiomorpholins

    , M.Sc. Thesis Sharif University of Technology Hosseyni, Morteza (Author) ; Mahmoudi Hashemi, Mohammad (Supervisor) ; Ziyaei Halimehjani, Azim (Supervisor)
    Abstract
    This project investigates on synthesis of β-amino carbonyl compounds with new approach to become closer to green chemistry principals.In this project, we investigated the synthesis of β-amino carbonyl compounds with aromatic amines and electron deficient alkenes in the Michael reaction using boric acid and glycerol in water as a green media. High yields of the products and easy handling are some advantages of this procedure. Also, we investigated the Michael reaction in different solvents and temperatures but gave better results in the aqueous media. Moreover, thiomorpholine derivatives were synthesized using this method to give excellent yield.
     

    Synthesis of Dithiocarbamate by Markonikov Addition Reaction

    , M.Sc. Thesis Sharif University of Technology Dadras, Arefeh (Author) ; Mahmoodi Hashemi, Mohammad (Supervisor) ; Ziyaei Halimehjani, Azim (Supervisor)
    Abstract
    Development of strategically important processes which are environmentally benign with simple methodology and work-up by low toxic material is currently reciving considerable attention.In recent years, dithiocarbamates (DTCs) and their synthesis with a green procedure have received many attention because of their undeniable applications.These synthetic compounds play important roles either in academia and industry. Here a simple, efficient and regiospecific method for synthesis of dithiocarbamates is described by one-pot three-component reaction of an amine, CS2 and alkyl vinyl ether via Markovnikov addition reaction in poly ethylene glycol (PEG) under a mild and green procedure with... 

    Investigation of Dithiocarabamates Reaction with α,β-Unsaturated Aldehydes

    , M.Sc. Thesis Sharif University of Technology Ramezani, Meraj (Author) ; Mahmoudi Hashemi, Mohammad (Supervisor) ; Ziyaei Halimehjani, Azim (Supervisor)
    Abstract
    Dithiocarbamates are a group of compounds that nowadays have been used extensively in pharmaceutical agents, organicsynthesis and as fungicides in agriculture.We haveshown, an efficient. regiospecific method for the synthesis of cyclic dithiocarbamates by one-pot three-component cascade reaction of an amine, CS2 and α,β-unsaturated aldehyde via Michael addition/hemiamination reaction in watre under a mild and green procedure with excellent yields and complete regioselectivity  

    Investigation of the Reaction of Dithiocarbamic Acid Salts with Carbonyl Compounds (Ketones and Aldehydes), Epoxides and Ortho Esters

    , M.Sc. Thesis Sharif University of Technology Hajiloo Shayegan, Mojtaba (Author) ; Mahmoodi Hashemi, Mohammed (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)
    Abstract
    In the first section, for the first time, a reaction of dithiocarbamic acid salts with carbonyl compounds has been investigated in the presence of BF3.OEt2. The reaction is temperature dependent meaning that the reaction gives two different products at low and high temperatures. At 15-20 0C, the 2-iminium-1,3-dithietane is the main product.As the reaction temperature goes up, formation of gem-bis(dithiocarbamates) is dominant.In addition, deprotection of gem-bis(dithiocarbamates) was investigated by using of nitric acid as the only deprotecting agent. The structure of a 2-iminium-1,3-dithietane was confirmed by X-ray crystallographic analysis.
    In the second and third sections, in our aim... 

    Synthesis of Bromonitroalkenes and their Applications as Electrophile in the Reaction with Indoles

    , M.Sc. Thesis Sharif University of Technology Rostami Rad, Marzieh (Author) ; Mahmoodi Hashemi, Mohammad (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)
    Abstract
    In this work Nitroolefins were made by aromatic aldehydes consisting of electron withdrawing and electron donor groups. Afterward β-Bromo-β-nitrostyrenes were produced from interaction between nitroolefins and brom, at suitable temperature. After providing ingredients, micheal reaction (Friedel-crafts Pseudo-alkylation) between nitroolefins and various nucleophiles such as indoles was investigated. Finally desired micheal products were achived with high efficiency  

    Distributed Robust Model Predictive Control for Multi-zone Air Conditioning Systems

    , M.Sc. Thesis Sharif University of Technology Azim Mezerji, Hojat (Author) ; Moradi, Hamed (Supervisor)
    Abstract
    Optimizing the energy consumption of air conditioning systems has gained great importance in recent years. In addition, maintaining thermal comfort and air quality in buildings is important. The multi-evaporator air conditioning system, which is a direct expansion system, shows the complex and distributed structure of air conditioning systems due to the thermal connection between zones and its large scale. The modeling of these systems is associated with uncertainties. Therefore, designing a suitable control structure for multi-zone systems is very important to achieve optimal energy consumption and maintain comfort conditions in the presence of uncertainty. Model predictive control has been... 

    Investigating Mechanism, Transition State, and Products Distribution of Catalys-Free Hydrothiolation Reactions of Unactivated Terminal Alkynes by Dithiocarbamic Acids

    , M.Sc. Thesis Sharif University of Technology Kolivand, Mohammad (Author) ; Ziyaei Halimehjani, Azim (Supervisor)
    Abstract
    In this study, catalyst-free hydrothiolation reactions of unactivated terminal alkynes by dithiocarbamic acids have been investigated via computational chemistry approach and by Gaussian 09, GaussVeiw 5.0, and Spartan '14 V1.1.4 software from the perspective of the reaction mechanism, transition state, and the distribution of products. The calculation results have shown that the various in situ produced dithiocarbamic acids addition to unactivated terminal alkynes in which the alkyl group attached to the carbon 2 is an aliphatic hydrocarbon alkyl is through Markovnikov type path and this product is thermodynamically more stable which is in agreement with the experimental results. The NBO... 

    Investigation of the Reaction of Dithiocarbamic Acid Salts with Fluorinating Agents

    , M.Sc. Thesis Sharif University of Technology Farhang, Amir Mohammad (Author) ; Ziyaei Halimejani, Azim (Supervisor)
    Abstract
    Dithiocarbamates have demonstrated extensive applications as synthetic intermediates in the synthesis of functional groups and heterocyclic rings. These compounds, due to their high nucleophilicity, are capable of reacting with a wide range of electrophiles, including aldehydes, alkyl halides, azo compounds, diazo compounds, and many others, yielding diverse and valuable products. This project aims to investigate the reaction of dithiocarbamate salts with fluorinating agents for the synthesis of thiocarbamoyl fluorides. Initially, dithiocarbamate salts were prepared via the reaction of amines with carbon disulfide and the presence of an inorganic base, followed by their conversion to target... 

    Synthesis of Dithiocarbamate Derivatives and Aminolysis of Epoxides in Water and under Different Conditions

    , M.Sc. Thesis Sharif University of Technology Gholami, Hadi (Author) ; Saeedi, Mohammad Reza (Supervisor) ; Ziyaei Halimehjani, Azim (Supervisor)
    Abstract
    This research project contains two parts that investigating new approaches for becoming closer to green chemistry principals is clear in it. In the first part we tried to synthesis dithiocarbamate salts using aromatic amins and than Michael addition of them to prepare bifunctional dithiocarbamats. But we found ?-thiols as final product. In the second part of this project, we investigated the regioselective epoxide ring opening with aromatic amines by using boric acid and glycerol in water as a green media. Corresponding ?-amino alcohols were obtained with excellent yields and considerable regioselectivity. High yields of the products, mild reaction conditions, using green catalyst and water... 

    The Reaction of α-Haloketones with Dithiocarbamate Derivatives for the Synthesis of 2-Alkylthiothiazole Heterocyclic Compounds

    , M.Sc. Thesis Sharif University of Technology Hasani, Leila (Author) ; Saeedi, Mohammad Reza (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)
    Abstract
    The reaction of α-haloketones with a variety of dithiocarbamate derivatives for the synthesis of various 2-alkylthiothiazole heterocyclic compounds was investigated in this thesis. To this end, different dithiocarbamates were initially synthesized through the reaction of amines, carbon disulfide and various alkyl halides; then, these dithiocarbamates were reacted with α-bromoketones (bromoacetophenone and chloroacetone) resulting in the formation of range of 2-alkyl thiothiazoles. To optimize the reaction conditions, ethanol and water were tested as solvents in the presence of ZrCl4 as catalyst. According to the data obtained, ethanol was selected as the optimum solvent using ZrCl4 as... 

    Synthesis of β-hydroxy dithiocarbamate derivatives via regioselective addition of dithiocarbamate anion to epoxide in water

    , Article Canadian Journal of Chemistry ; 2006, 84, 1515-1519 Ziyaei-Halimjani, A. (Azim) ; Saidi, M. R ; Sharif University of Technology
    Abstract
    The reactions of different dithiocarbamate anions with epoxides were investigated in water. With this method, β-hydroxy dithiocarbamate derivatives were synthesized in high yields. The reaction was also carried out in DMF in the presence of lithium perchlorate with a simple work-up procedure, and the results are compared  

    Investigation of One-Pot Three-Component Reaction of Naphthalenediols with Formaldehyde and Amines under Catalyst-free Conditions

    , M.Sc. Thesis Sharif University of Technology Nayebi Gavgani, Hadi (Author) ; Saidi, Mohammad Reza (Supervisor) ; Ziyaei Halimehjani, Azim (Supervisor)
    Abstract
    In this study, a catalyst-free Mannich reaction is applied for synthesis of 1,3-oxazines as an important class of biologically active compounds. In order to consider environmental application a mixture of water and ethanol is selected as a solvent for the reaction of 2,7-dihydroxynaphthalene with formaldehyde and an amine. Primary consideration of substitution effect on the reaction revealed that aniline and its derivatives with electron-donating substituent and halogens, cause higher yield. Aliphatic amines are not good substrate for this reaction with the exception of benzyl amine  

    Synthesis and Characterization of Dithiocarbamate Complex Derivatives of 3-((Pyridin-2-yl)Methyl Amino)Propannitril

    , M.Sc. Thesis Sharif University of Technology Torabi, Saeedeh (Author) ; Saeedi, Mohammad Reza (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)
    Abstract
    Dithiocabamates are valuable compounds due to their wide application as herbicides, fungicides, antitumor and etc. Another aspect of dithiocarbamates is their application in coordination chemistry. In this project, 3-((pyridin-2-yl) methyl amino) propane nitrile was prepared via Michael addition reaction of 1-methyl¬amino¬pyridine and acrylonitrile in water. Then this compound was converted to its potassium dithiocarbamate salt via treatment with carbon disulfide in the presence of potassium hydroxide in tetrahydrofuran. The prepared ligand was used in complexation with metal salts of Zn, Hg, Ni and Sn to prepare their dithiocarbamate complexes. The structure of complexes was elucidated by... 

    ALR detector for coherent radar detection of rapid fluctuating signals

    , Article IEICE Transactions on Communications ; Volume E83-B, Issue 11 , 2000 , Pages 2519-2525 ; 09168516 (ISSN) Modarres Hashemi, M ; Sharif University of Technology
    Institute of Electronics, Information and Communication, Engineers, IEICE  2000
    Abstract
    In this paper, we consider the coherent radar detection of rapid fluctuating signals in the Gaussian noise. This problem has been previously solved by employing the GLR technique, but we use the ALR to improve the detection performance. So, after deriving an approximate ALR detector, we compare the new detector with the GLR and ' Square-law detectors and we show its superiority  

    Synthesis of New Dithiocarbamate Complexes Based on Diamines Prepard from Cinnamaldehyde

    , M.Sc. Thesis Sharif University of Technology Soleymani Movahed, Farzaneh (Author) ; Saeedi, Mohammad Saeed (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)
    Abstract
    Dithiocarbamate is one of the most useful components in the science of chemistry. They are used not only in agriculture as fungicides but also in photochemistry in order to determine and analyse NO in biological processes as well as in polymerization routes. Dithiocarbamates which are known as bidentate ligands with high yield are applied in many fields such as producing chemical drugs, functioning as intermediates in organic synthesis, protecting groups in peptide synthesis as well as highly chelating ligands. Regarding the high practically of dithiocarbamates and by focusing on their synthesis process, we have applied them as bidentate ligands. Cinnamaldehyde was condensed in ethanol with... 

    Coronary artery lipid accumulation prevention through vibrating piezo electric nano plates embedded in smart stent

    , Article Medical Engineering and Physics ; Volume 118 , 2023 ; 13504533 (ISSN) Ahmadi Arpanahi, R ; Hosseini Hashemi, K ; Ahmadian, M. T ; Mohammadi, B ; Hosseini Hashemi, S ; Sharif University of Technology
    Elsevier Ltd  2023
    Abstract
    Considering the lipid concentration and side effects regarding the stents used by surgeons, a new heart stent model is proposed. In the new stent, a few piezo plates are designed and attached to the stents by which release of the lipids can take place due to the applied alternative voltages. Due to the vibrations of small-scale piezoelectric plates, the deposition of low-density-lipoproteins (LDL) floating in the blood flow in the coronary arteries is prevented. Small-scale effects are considered using nonlocal elasticity theory, and the interaction between fluid and solid is modeled using the Navier-Stokes equation. The effect of fluid parameters as well as applied voltage and geometry... 

    Empirical comparison of sliding friction and wear behaviors of gray and white cast iron

    , Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 1 , 2010 , Pages 489-493 ; 9780791849156 (ISBN) Hashemi, M ; Ghajar, R ; Sharif University of Technology
    2010
    Abstract
    In this paper, sliding friction and wear behaviors of gray cast iron A35 and white cast iron manufactured by quenching from the same cast iron in water were studied and compared by employing pin-on-disk wear tests. Microstructure of the worn surfaces before and after the wear tests were investigated by optical microscope observations. These images show that flakes separated from the surface in gray cast iron due to delamination process, while in white cast iron, the separation of materials from its surface is in the form of powder. In addition, the gray cast iron had higher graphite volume fraction with Type-A graphite flake morphology. The results show that white cast iron has less rate of... 

    Investigation of the small-scale effects on the three-dimensional flexural vibration characteristics of a basic model for micro-engines

    , Article Acta Mechanica ; Volume 226, Issue 9 , September , 2015 , Pages 3085-3096 ; 00015970 (ISSN) Hashemi, M ; Asghari, M ; Sharif University of Technology
    Springer-Verlag Wien  2015
    Abstract
    The coupled three-dimensional flexural vibrations of a micro-rotating shaft–disk system, as a basic model for micro-engines, are investigated in this paper by considering small-scale effects utilizing the modified couple stress theory. Governing equations of motion are derived by the use of Hamilton’s principle. Then, implementing the Galerkin approach, an infinite set of ordinary differential equations is obtained for the system. With truncated two-term equations, expressions for the first two natural frequencies are written, and for the two corresponding modes, the maximum rotational speed up to which the system will be stable is analytically determined. Parametric studies on the results... 

    Analytical study of three-dimensional flexural vibration of micro-rotating shafts with eccentricity utilizing the strain gradient theory

    , Article Meccanica ; Volume 51, Issue 6 , 2016 , Pages 1435-1444 ; 00256455 (ISSN) Hashemi, M ; Asghari, M ; Sharif University of Technology
    Springer Netherlands  2016
    Abstract
    In this work, some vibrational response parameters of strain gradient based micro-spinning Rayleigh beams with mass eccentricity distribution are investigated within infinitesimal deformation conditions. Governing equations of motion are derived utilizing the Hamilton’s principle. The gyroscopic effects and rotary inertia are both included in the formulation. By applying the Galerkin method, analytical expressions for natural frequencies of the micro beam in forward and backward whirl motions are obtained. In addition, an expression for the vibrational amplitude of the micro-beam due to mass eccentricity distribution is determined. Some numerical results are presented to study the effect of...