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Synthesis, characterization, and catalytic activity of supported molybdenum Schiff base complex as a magnetically recoverable nanocatalyst in epoxidation reaction
, Article Journal of Coordination Chemistry ; Volume 69, Issue 4 , 2016 , Pages 668-677 ; 00958972 (ISSN) ; Zare, M ; Bagherzadeh, M ; Ozkar, S ; Akbayrak, S ; Sharif University of Technology
Taylor and Francis Ltd
2016
Abstract
A heterogeneous nanocatalyst was prepared via covalent anchoring of dioxomolybdenum(VI) Schiff base complex on core-shell structured Fe3O4@SiO2. The properties and the nature of the surface-fixed complex have been identified by a series of characterization techniques such as SEM, EDX, XRD, TGA, FT-IR, and VSM. The synthesized hybrid material was an efficient nanocatalyst for selective oxidation of olefins to corresponding epoxides with t-BuOOH in high yields and selectivity. The catalyst could be conveniently recovered by applying an external magnetic field and reused several times without significant loss of efficiency. © 2016 Taylor and Francis
ONO pincer type binuclear Pd(II) complex: Synthesis, crystal structure and catalytic utilization of the resulting organopalladium complex in catalytic copper-free Sonogashira coupling reaction
, Article Inorganica Chimica Acta ; Volume 451 , 2016 , Pages 227-232 ; 00201693 (ISSN) ; Mousavi, N. A ; Zare, M ; Jamali, S ; Ellern, A ; Woo, L. K ; Sharif University of Technology
Elsevier S.A
2016
Abstract
New binuclear palladium (II) complex featuring ONO pincer type hydrazone ligand was synthesized and characterized by spectroscopic and single-crystal XRD analysis. This complex showed excellent catalytic activity towards the copper-free Sonogashira cross coupling reaction. The main advantages over previous methodologies include low catalyst loading, less problematic reaction media (H2O–DMSO) and reusability in homogenous systems for optimal performance
Enhancement of surface adsorption-desorption rates in microarrays invoking surface charge heterogeneity
, Article Sensors and Actuators, B: Chemical ; 2016 ; 09254005 (ISSN) ; Saidi, M. S ; Sadeghi, A ; Sharif University of Technology
Elsevier B.V
2016
Abstract
This investigation is devoted to the influences of non-uniform wall characteristics on the surface adsorption-desorption rates in an electrokinetic microarray. Utilizing already explored electroosmotic and electrophoretic velocities, the species transport equations are solved by a finite-volume-based numerical approach. Uniform, sinusoidal, and pulse-like distributions of the zeta potential are considered in the analysis. The developed model is validated by comparing the results with those of two analytical solutions that are derived for limiting conditions. The results reveal that, in some cases, the surface charge heterogeneity can reduce the saturation time by more than 60%. The efficacy...
Reactions of doubly deprotonated 2,6-naphthalenedicarboxylic acid with alcohols: Proton transfer versus solvation
, Article International Journal of Mass Spectrometry ; 2016 ; 13873806 (ISSN) ; Meyer, M. M ; O'Hair, R. A. J ; Fattahi, A ; Schmidt, J ; Kass, S. R ; Sharif University of Technology
Elsevier B.V
2016
Abstract
Electrospray ionization of 2,6-naphthalenedicarboxylic acid readily affords its doubly deprotonated dicarboxylate dianion (1 2-). This species clusters with background water and added alcohols in an ion trap at ∼10-3 Torr. Sequential solvation is observed to afford mono and dicoordinated ions. Surprisingly, the latter cluster (1 2- • 2TFE) is protonated by 2,2,2-trifluoroethanol (TFE) whereas 1 2-and 1 2- • TFE are not even though δHacid(TFE)=361.7±2.5kcalmol-1 (as given in the NIST website at http://webbook.nist.gov) and the B3LYP/6-31+G(d,p) proton affinities are 384.7 (1 2-), 377.6 (1 2- • TFE), and 362.7 (1 2- • 2TFE) kcal mol-1. That is, only the weakest base in this series, and the...
Bi(OTf)3-catalysed domino Friedel-Crafts alkylation of arenes with aldehydes: An upgraded method for efficient synthesis of triarylmethanes and anthracene derivatives
, Article Tetrahedron ; Volume 72, Issue 11 , 2016 , Pages 1433-1439 ; 00404020 (ISSN) ; Mohammadpoor Baltork, I ; Tangestaninejad, S ; Moghadam, M ; Mirkhani, V ; Kia, R ; Sharif University of Technology
Elsevier Ltd
Abstract
A variety of novel triarylmethanes including bis-(dihexyloxyphenyl)arylmethanes and diveratrylmethanes were prepared by the domino Friedel-Crafts alkylation of arenes with aldehydes catalysed by Bi(OTf)3. The reaction of veratrole with aromatic dialdehydes afforded different results based on the molar ratio of reactants and the nature of aromatic dialdehydes. Bi(OTf)3/O2 is shown to be a highly efficient reagent system to promote the tandem three-step reaction of acylals with bis-(dihexyloxyphenyl)arylmethanes or diveratrylmethanes for the preparation of 9,10-disubstituted-2,3,6,7-tetraalkoxyanthracenes. The substrate scope, the simplicity of the reactions and work-up processes, besides a...
Droplet-based flows in serpentine microchannels: chemical reactions and secondary flows
, Article International Journal of Multiphase Flow ; Volume 97 , 2017 , Pages 186-196 ; 03019322 (ISSN) ; Shamloo, A ; Sharif University of Technology
Abstract
Mixing is an essential operation in many microfluidic devices. Droplet-based micromixers utilize droplets for mixing enhancement. In the present study, a novel three-dimensional simulation is conducted which has the ability to capture not only the mixing process, but also the chemical reactions inside liquid droplets. This two-phase model is used for simulating the reacting flow inside a serpentine microchannel and explores the effects of droplet size and reaction rate on the production and consumption of species in droplets. It is observed that the chemical reaction in each droplet, begins from its front area. Furthermore, it is shown that the production of species does not depend on water...
Reactions of doubly deprotonated 2,6-naphthalenedicarboxylic acid with alcohols: Proton transfer versus solvation
, Article International Journal of Mass Spectrometry ; Volume 418 , 2017 , Pages 180-187 ; 13873806 (ISSN) ; Meyer, M. M ; O'Hair, R. A. J ; Fattahi, A ; Schmidt, J ; Kass, S. R ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Electrospray ionization of 2,6-naphthalenedicarboxylic acid readily affords its doubly deprotonated dicarboxylate dianion (12−). This species clusters with background water and added alcohols in an ion trap at ∼10−3 Torr. Sequential solvation is observed to afford mono and dicoordinated ions. Surprisingly, the latter cluster (12−• 2TFE) is protonated by 2,2,2-trifluoroethanol (TFE) whereas 12−and 12−• TFE are not even though ΔH°acid(TFE) = 361.7 ± 2.5 kcal mol−1 (as given in the NIST website at http://webbook.nist.gov) and the B3LYP/6-31+G(d,p) proton affinities are 384.7 (12−), 377.6 (12−• TFE), and 362.7 (12−• 2TFE) kcal mol−1. That is, only the weakest base in this series, and the dianion...
Surfactant-Like brønsted acidic ionic liquid as an efficient catalyst for selective mannich reaction and biodiesel production in water
, Article Journal of the Iranian Chemical Society ; Volume 14, Issue 4 , 2017 , Pages 907-914 ; 1735207X (ISSN) ; Karbalaie Reza, M ; Mahmoodi Hashemi, M ; Qasempour Soleimany, K ; Sharif University of Technology
Springer Verlag
2017
Abstract
Abstract: The current study deals with the applications of a surfactant-like Brønsted acidic ionic liquid (IL) 1-dodecyl-3-methylimidazolium hydrogen sulfate ([DMIm]HSO4) for Mannich reaction at room temperature. The reaction was efficiently preceded in water as solvent without using any harmful and expensive organic additives. Our findings showed that the reaction is selective for cyclohexanone and no Mannich product was observed when cyclopentanone was used as starting material. Density functional theory (DFT) calculations were performed to provide an evidence about the nature of reactivity of the cyclohexanone/cyclopentanone. The activity of the catalyst was also tested for biodiesel...
Halogen-lithium exchange reaction using an integrated glass microfluidic device: an optimized synthetic approach
, Article Organic Process Research and Development ; Volume 21, Issue 3 , 2017 , Pages 292-303 ; 10836160 (ISSN) ; Mohammadi, A ; Sharif University of Technology
American Chemical Society
2017
Abstract
A telescoped approach was developed for the efficient synthesis of methoxybenzene through the generation of an unstable intermediate reagent, based on the Br-Li exchange reaction of p-bromoanisole and n-BuLi, followed by its reaction with water. In the first stage, p-methoxyphenyllithium was synthesized and consumed immediately in the second stage. For this purpose, an integrated glass microfluidic device was fabricated using laser ablation followed by the thermal fusion bonding method. The impact of various parameters, including solvent, reaction time, molar ratio, concentration of reagents, and flow rates were investigated to achieve the highest yield of the desired product, leading to an...
Designed model for the Morita–Baylis–Hillman reaction mechanism in the presence of CaO and CaO modified with ionic liquid as a solid base catalyst: a DFT and MP2 investigation
, Article Theoretical Chemistry Accounts ; Volume 137, Issue 9 , 2018 ; 1432881X (ISSN) ; Rahman Setayesh, S ; Sharif University of Technology
Springer New York LLC
2018
Abstract
The new model for the Morita–Baylis–Hillman reaction based on the proton transfer were inquired by MP2 and DFT methods with 6-311G++(d, p) basis set combined with IEF-PCM solvent model. We focused on the reaction between acrylonitrile and benzaldehyde, catalyzed by CaO cluster and CaO modified with [Pyr][HSO4] ionic liquid. Our results indicate that in the presence of ionic liquid, the ionic liquid acts as a shuttle for the proton transfer between species in a lower energy pathway. The proton transfer step from enolate to catalyst is predicted to be the rate-limiting step for the whole process. In order to investigate the catalyst basicity, the pKa values of acrylonitrile and methyl acrylate...
Decomposition of tributhyl phosphate at supercritical water oxidation conditions: Non-catalytic, catalytic, and kinetic reaction studies
, Article Journal of Supercritical Fluids ; Volume 133 , 2018 , Pages 103-113 ; 08968446 (ISSN) ; Golmohammadi, M ; Towfighi, J ; Ahmadi, S. J ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Tributhyl phosphate (TBP) decomposition in supercritical water oxidation (SCWO) was performed with and without catalyst, at different temperatures ranging from 370 to 480 °C, and different reaction times. Ag2O, CuO, Fe2O3, MgO, and ZnO synthesized by supercritical water were examined in TBP decomposition as the catalyst. TBP structure decomposed under the non-catalytic reaction; nevertheless, the results indicated that the use of catalysts improved the reaction efficiency, which calculated based on total organic carbon (TOC) removal, by far. However, TOC removal using Fe2O3 was 20% higher than the non-catalytic reaction. Having the ability in completion of the redox cycle, iron oxide...
Magnetic nanocomposite of cross-linked Mmelamine groups decorated with large amounts of gold NPs: reduction of nitro compounds and Suzuki–Miyaura coupling reactions in aqueous media
, Article ChemistrySelect ; Volume 3, Issue 10 , March , 2018 , Pages 2716-2722 ; 23656549 (ISSN) ; Keshavarzi, N ; Matloubi Moghaddam, F ; Hosseini, S. H ; Sharif University of Technology
Wiley-Blackwell
2018
Abstract
A magnetic nanocomposite was prepared based on magnetic Fe3O4 nanoparticles entrapped into a cross-linked nitrogen rich polymer which has high loading capacity for immobilization of gold nanoparticles. The synthesized catalyst was characterized using various methods including Atomic absorption spectroscopy (AAS), Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), Thermogravimetric analysis (TGA), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), VSM and X-ray diffraction (XRD) techniques. The catalyst was proven to be highly efficient for reduction of nitroarenes as well as Suzuki–Miyaura...
A survey on exergy, energy and environmental analysis of sulfur recovery unit in case of five intensified configurations
, Article Chemical Papers ; Volume 73, Issue 6 , 2019 , Pages 1529-1539 ; 03666352 (ISSN) ; Tavan, Y ; Sharif University of Technology
Springer International Publishing
2019
Abstract
In this study, a combination of energy and exergy analysis is applied for the industrial sulfur recovery unit (SRU) in commercial simulation software. The data of energy and exergy are obtained from the simulator and Excel (for physical and chemical exergy), respectively. In doing so, five intensified SRU configurations namely: (1) hot gas bypass (2) acid gas bypass (3) inlet stream preheating (4) acid gas enrichment and (5) oxygen (air) enrichment are compared in terms of energy production, reaction furnace temperature, sulfur recovery and pollutant emission into environment. Then, irreversibility in these five arrangements is compared and all the proposed methods show higher useful exergy...
Hexyltriphenylphosphonium bromide as an absolutely chemoselective ionic liquid catalyst in the three-component reaction of aryl aldehydes, acetophenones and malononitrile
, Article ChemistrySelect ; Volume 4, Issue 20 , 2019 , Pages 6190-6193 ; 23656549 (ISSN) ; Khodaei, M. M ; Batooie, N ; Hosseinzadeh, N ; Foroumadi, A ; Sharif University of Technology
Wiley-Blackwell
2019
Abstract
Hexyltriphenylphosphonium bromide (HTPB) is used as an efficient ionic liquid catalyst in the chemoselective addition of malononitrile to carbonyl group moiety of chalcones through the three-component reaction of aryl aldehydes, acetophenone derivatves, and malononitrile to produce (E)-2-(1,3-diarylallylidene)malononitriles at ambient temperature. The method is simple, solvent-free, environmentally friendly, and gives excellent yields in a short reaction times. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Calixarene based ionic liquid as an efficient and reusable catalyst for one-pot multicomponent synthesis of polysubstituted pyridines and BIS-pyridines
, Article ChemistrySelect ; Volume 4, Issue 19 , 2019 , Pages 5903-5910 ; 23656549 (ISSN) ; Mohammadpoor Baltork, I ; Tangestaninejad, S ; Mirkhani, V ; Moghadam, M ; Kia, R ; Sharif University of Technology
Wiley-Blackwell
2019
Abstract
In this work, a calixarene based ionic liquid was successfully prepared and characterized by different techniques. This ionic liquid was used as an efficient catalyst for the synthesis of a series of polysubstituted pyridines from aldehydes, malononitrile, 1,3-diketones and arylamines in water as a green solvent. Also, for the first time, symmetric and unsymmetric polysubstituted bis-pyridines were obtained in high yields from diamines using this catalyst. Mild reaction conditions, high to excellent yields, easy work-up, excellent activity and reusability of the catalyst are the key features of this method which make it an interesting and novel alternative for the synthesis of the above...
Kinetics study of a Diels-Alder reaction in mixtures of an ionic liquid with molecular solvents
, Article Journal of Physical Organic Chemistry ; Volume 21, Issue 9 , 2008 , Pages 783-788 ; 08943230 (ISSN) ; Habibi Yangjeh, A ; Gholami, M. R ; Sharif University of Technology
2008
Abstract
The second-order rate constants for cycloaddition reaction of cyclopentadiene with naphthoquinone were determined spectrophotometrically in various compositions of 1-(1-butyl)-3-methylimidazolium terafluoroborate ([bmim]BF4) with water and methanol at 25°C. Rate constants of the reaction in pure solvents are in the order of water > [bmim]BF 4 > methanol. Rate constants of the reaction decrease sharply with mole fraction of the ionic liquid in aqueous solutions and increase slightly to a maximum in alcoholic mixtures. Multi-parameter correlation of logk 2 versus solute-solvent interaction parameters demonstrated that solvophobicity parameter (Sp), hydrogen-bond donor acidity (α) and...
Kinetic mechanism reduction using genetic algorithms, case study on H 2/O2 reaction
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 26, Issue 3 , 2007 , Pages 1-9 ; 10219986 (ISSN) ; Pishvaie, M. R ; Bozorgmehry, R ; Sharif University of Technology
2007
Abstract
For large and complex reacting systems, computational efficiency becomes a critical issue in process simulation, optimization and model-based control. Mechanism simplification is often a necessity to improve computational speed. We present a novel approach to simplification of reaction networks that formulates the model reduction problem as an optimization problem and solves it using genetic algorithm (GA).The aim of simplification kinetics modeling is to derive the simplest reaction system, which retains the essential features of the full system. Numerical results for H2/O2 combustion reaction mechanism illustrate the potential and proficiency of this approach
One-pot synthesis of dithiocarbamates accelerated in water
, Article Journal of Organic Chemistry ; Volume 71, Issue 9 , 2006 , Pages 3634-3635 ; 00223263 (ISSN) ; Aryanasab, F ; Torkiyan, L ; Ziyaei, A ; Saidi, M. R ; Sharif University of Technology
2006
Abstract
Highly efficient one-pot reactions of amines and carbon disulfide with α,β-unsaturated compounds were carried out in water under a mild and green procedure with high yields. © 2006 American Chemical Society
Enhanced electrochemical activity of Co3O4/Co9S8 heterostructure catalyst for water splitting
, Article International Journal of Hydrogen Energy ; 2021 ; 03603199 (ISSN) ; Ahmad, I ; Rashid, N ; Zafar, M. N ; Shehzad, F. K ; ullah, Z ; Ul-Hamid, A ; Nazar, M.F ; Junaid, M ; Faheem, M ; Shafqat, S. S ; Jabeen, U ; Dahshan, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The dearth of efficient, robust, and economical electrocatalysts for water oxidation is dubiously the key obstacle for renewable energy devices, so synthesis of efficient, and cost-effective metal-based water oxidation catalysts is vital. Herein, Co3O4, Co9S8 catalysts and their heterostructure Co3O4/Co9S8 were synthesized and evaluated as water oxidation electrocatalysts. The characterization of Co3O4, Co9S8, and Co3O4/Co9S8 electrocatalysts was performed using Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction techniques. The heterostructure Co3O4/Co9S8 (1.46 V) exhibited water oxidation electrocatalysis at extremely low onset potential compared to...
A facile one-pot, four-component synthesis of (Z)-isomer of rhodanine-oxindole derivatives under environmentally benevolent conditions
, Article Synthetic Communications ; 2021 ; 00397911 (ISSN) ; Aghamiri, B ; Jalalinik, M ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
Herein, an efficient and sustainable one-pot, four-component access to rhodanine-oxindole derivatives is achieved by a reaction between primary amines, carbon disulfide, ethyl chloroacetate, and cyano-substituted alkenyl oxindoles. The reaction was conducted without any harsh conditions as well as exhausting workup in polyethylene glycol (PEG) as a green solvent at room temperature and delivered rhodanine-oxindole products in high yield. This publication is the first easy protocol to be reported for the rapid construction of new rhodanine-oxindole derivatives at room temperature without harsh conditions and via multicomponent reaction. © 2021 Taylor & Francis Group, LLC