Search for: palladium
Total 118 records
Palladium and copper complexes with oxygen-nitrogen mixed donors as efficient catalysts for the Heck reaction, Article Inorganica Chimica Acta ; Volume 383 , 2012 , Pages 46-51 ; 00201693 (ISSN) ; Amini, M ; Ellern, A ; Keith Woo, L ; Sharif University of Technology
A simple bidentate ligand, 2-(2′-hydroxyphenyl)-5,6-dihydro-1,3- oxazine, was readily prepared with a two-step synthesis. Two novel complexes of Pd(II) and Cu(II) with this (N,O) oxazine ligand have been prepared and the molecular structures of these complexes have been confirmed by X-ray structure analysis, NMR, IR and UV-Vis spectroscopy. These complexes efficiently catalyze the Heck reaction of aryl halides with olefins at 120 °C in 8 h. The reaction conditions for the Heck coupling of iodobenzene with styrene was optimized by varying the amount of the catalyst, reaction temperature, solvent and exogenous base
The possibilities of palladium-catalyzed aromatic cyanation in aqueous media, Article Inorganic Chemistry Communications ; Volume 72 , 2016 , Pages 86-90 ; 13877003 (ISSN) ; Mahmoodi Hashemi, M ; Karbalaie Reza, M ; Sharif University of Technology
Owing to the inherent incompatibility with water, cyanation of aryl halides may be the most challenging category of palladium-catalyzed coupling reactions. The major challenges are attributed to the catalyst deactivation by the soluble cyanide (CN−) ions and desirable conversions only could be obtained by employing toxic organic solvents. The current minireview highlights mechanistic insights and breakthrough achievements for this reaction in the aqueous media
A catalyzed method to remove polychlorinated biphenyls from contaminated transformer oil, Article Environmental Science and Pollution Research ; 2021 ; 09441344 (ISSN) ; Gholipour Zanjani, N ; Khorasheh, F ; Arjmand, M ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH 2021
The disposal of polychlorinated biphenyls (PCBs) as persistent organic pollutants from the environment has been normally performed by isolation from soil or water because of their biological activity and toxic potential. In the present investigation, catalytic hydrodehalogenation was used to detoxify PCBs-contaminated transformer oil. All reactions were directed on an oil containing 11.09 wt% of PCBs utilizing palladium supported on multi-walled carbon nanotubes (Pd/MWCNTs). The amount of hexa-chlorine homologues reduced considerably from 5.07% to less than 800 ppm utilizing HDC at the atmosphere of argon. Moreover, the amounts of long half-lives and bioaccumulative congener of PCB 153...
Novel unsymmetrical tetradentate Schiff base complexes of cobalt (II) and palladium (II) with N2O2 donor sets, Article Journal of Chemical Research - Part S ; Issue 6 , 2001 , Pages 224-226 ; 03082342 (ISSN) ; Mohebi, S ; Sharif University of Technology
The novel unsymmetrical tetradentate Schiff base complexes of Co(II) and Pd(II) with the general formula M(SaI.Phen.Acac.) and M(Sal.Phen. Naph.), have been synthesised by template and non-template method
Polymer-Supported Bis-1,2,4-triazolium ionic tag framework for an efficient Pd(0) catalytic system in biomass derived γ-valerolactone, Article ACS Sustainable Chemistry and Engineering ; Volume 7, Issue 7 , 2019 , Pages 6939-6946 ; 21680485 (ISSN) ; Mahmoudi, H ; Bivona, L. A ; Piermatti, O ; Bagherzadeh, M ; Fusaro, L ; Aprile, C ; Marrocchi, A ; Vaccaro, L ; Sharif University of Technology
American Chemical Society 2019
A resin-bound 1,2,4-triazolium ionic tag has been used as support for the preparation of solid palladium nanoparticles (Pd(0)-POLI-TAG-Pd). Owing to the pincer-type architecture of the triazolium ligand, the stabilization of a high amount of palladium nanoparticles (16 wt %) has been possible. The catalytic system has been fully characterized and used in low amounts (i.e., 0.1 mol % palladium loading) in representative Heck-Mizoroki cross-coupling processes. A negligible release of the metal was demonstrated, and a high activity was obtained over more runs. Besides, the protocol has been optimized for the use of safe biomass-derived γ-valerolactone reaction medium
The decoration of TiO2/reduced graphene oxide by Pd and Pt nanoparticles for hydrogen gas sensing, Article International Journal of Hydrogen Energy ; Volume 37, Issue 20 , October , 2012 , Pages 15423–15432 ; Ghasemi, S. (Shahnaz) ; Irajizada, A. (Azam) ; Akhavana, O. (Omid) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
Reduced graphene oxide (RGO) was used to improve the hydrogen sensing properties of Pd and Pt-decorated TiO2 nanoparticles by facile production routes. The TiO2 nanoparticles were synthesized by sol–gel method and coupled on GO sheets via a photoreduction process. The Pd or Pt nanoparticles were decorated on the TiO2/RGO hybrid structures by chemical reduction. X-ray photoelectron spectroscopy demonstrated that GO reduction is done by the TiO2 nanoparticles and Ti–C bonds are formed between the TiO2 and the RGO sheets as well. Gas sensing was studied with different concentrations of hydrogen ranging from 100 to 10,000 ppm at various temperatures. High sensitivity (92%) and fast response time...
Phenyltetrazole as a new ligand for immobilization of palladium nanoparticles on SBA‐15: a new robust catalyst with high loading of Pd for rapid oxidation and reduction, Article ChemistrySelect ; Volume 3, Issue 24 , 2018 , Pages 6779-6785 ; 23656549 (ISSN) ; Saberi, V ; Kalvani, P ; Sharif University of Technology
In this work, a new catalyst based on palladium nanoparticle supported SBA-15 has been introduced. The designed catalyst was characterized by Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) surface area analysis, thermo gravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDS) and atomic absorption spectroscopy (AAS) analyses. For the first time, phenyltetrazole has been used as a ligand to the functionalization of SBA-15 to design robust heterogeneous catalyst with high-loading metal for reduction and oxidation in short time using a low amount of the catalyst. © 2018...
Palladium immobilized onto functionalized magnetic nanoparticles as robust catalysts for amination and room-temperature ullmann homocoupling of aryl halides: a walk around the C−F bond activation, Article Asian Journal of Organic Chemistry ; Volume 7, Issue 4 , 2018 , Pages 802-809 ; 21935807 (ISSN) ; Pourkaveh, R ; Karimi, A ; Ayati, E ; Sharif University of Technology
Wiley-VCH Verlag 2018
The first example of a heterogeneous catalytically active system for Buchwald–Hartwig and Ullmann homocoupling of unactivated aryl halides (fluorobenzene) is presented. The novel magnetic heterogeneous palladium catalyst was synthesized by immobilization of palladium ions onto an aminopyridine-functionalized Fe3O4. The catalyst was fully characterized by FTIR spectroscopy, temperature-programmed reduction, thermogravimetric analysis, CHN elemental analysis, transmission electron microscopy, field-emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and atomic absorption spectroscopy. By using this catalyst system, various types of primary and...
A ligand and palladium-free avenue for cyanation of aryl Halides: The art of samarium powder in C–C coupling reaction, Article ChemistrySelect ; Volume 4, Issue 33 , 2019 , Pages 9618-9621 ; 23656549 (ISSN) ; Pourkaveh, R ; Gholamtajari, M ; Karimi, A ; Sharif University of Technology
This is the first study of samarium powder catalyzed cyanation reaction of aryl halides, bearing electron-withdrawing and electron-releasing substituents, in the presence of NaCN to afford corresponding benzonitriles in high yields. This protocol takes the advantage of being done in the absence of additive, ligand and precious transition metals such as palladium. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Taking advantage of the coordinative behavior of a tridentate schiff base ligand towards Pd2+ and Cu2+, Article Crystals ; Volume 9, Issue 8 , 2019 ; 20734352 (ISSN) ; Fondo, M ; Zarepour Jevinani, M ; García Deibe, A. M ; Sharif University of Technology
MDPI AG 2019
We have explored the suitability of an O,N,N–donor Schiff base (H2SB) for obtaining dinuclear complexes with heavy metal ions such as Cu2+, Zn2+, Ni2+, and Co2+ (borderline acids) as well as Pd2+ and Cd2+ (soft acids). Spectroscopic studies demonstrated that the complexation of H2SB and Cu2+, Zn2+, Ni2+, Co2+, Pd2+, and Cd2+ occurred at a 1:1 stoichiometry. We have found two square planar centers with Pd-N-Pd angles of 93.08(11)◦ and a Pd–Pd distance of 3.0102(4) Å in Pd2(SB)2·Me2CO. This Pd–Pd distance is 30% shorter than the sum of the van der Waals radii, which is in accordance with a strong palladophilic interaction. Fluorescence studies on H2SB-M2+ interaction showed that H2SB can...
Synthesis of chiral palladium oxazolidine and imine complexes: Investigation the oxazolidine-imine conversion by DFT method, Article Polyhedron ; Volume 160 , 2019 , Pages 130-138 ; 02775387 (ISSN) ; Moghadam, M ; Mirkhani, V ; Tangestaninejad, S ; Mohammadpoor Baltork, I ; Abbasi Kajani, A ; Kia, R ; Sharif University of Technology
Elsevier Ltd 2019
Reaction of 2-pyridinecarboxaldehyde with L-Alaninol (as a chiral amine) or 2-amino-2-methyl-1-propanol (AMP) in the presence of PdCl2 produced the new and attractive palladium(II) complexes which were synthesized by in situ method. The presence of an extra methyl group in AMP other than L-Alaninol induced the different chelating mode and, therefore, several structurally different palladium complexes obtained. Correspondingly, the chiral amine with PdCl2 produced the imine product, (Iminol (1)), and an oxazolidine compound (Imizol (1′)) as minor product. Also, the use of AMP in formation of palladium complexes led to the synthesis of imine (Ampynol (2)) and oxazolidine (Ampyzol (3))...
Palladium plating on macroporous/microporous silicon: application as a hydrogen sensor, Article Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry ; Volume 37, Issue 5 , 2007 , Pages 377-380 ; 15533174 (ISSN) ; Iraji Zad, A ; Razi, F ; Sharif University of Technology
Porous silicon samples are obtained by electrochemical method on n-type wafers in room light. Scanning electron microscopy showed that the porous structure consisted of macropores under a thin microporous layer. Placing the samples in Pd-electroless solution causes the crakes inside the microporous layer and growth of the palladium particles in these crakes. However, removing the microporous layer by KOH solution with an ultrasonically assisted process makes the growth of rather uniform palladium particles on the surface in electroless plating. Variation of the electrical resistance in the presence of diluted hydrogen at room temperature revealed that the best samples have the ability to...
Effective factors on Pd growth on porous silicon by electroless-plating: Response to hydrogen, Article Sensors and Actuators, B: Chemical ; Volume 115, Issue 1 , 2006 , Pages 164-169 ; 09254005 (ISSN) ; Iraji zad, A ; Sharif University of Technology
Porous silicon samples obtained from p+-type silicon wafers were impregnated with Pd by electroless process in different conditions. Scanning electron microscopy was used to study the change in the features of the surface after palladium plating. Results showed how the factors like Pd-salt concentration, HCl concentration, temperature of the electroless solution and the time of process affect on the growth and nucleation of Pd particles. Observations demonstrated that illumination-assisted process and pre-oxidation of the surface before process have drastic effect on the growth of palladium. Variation of the electrical resistance in the presence of diluted hydrogen at room temperature...
Hydro-purification of crude terephthalic acid using palladium catalyst supported on multi-wall carbon nanotubes, Article Journal of Industrial and Engineering Chemistry ; 2015 ; ISSN: 1226086X ; Khorasheh, F ; Rashidi, A. M ; Safekordi, A. A ; Sharif University of Technology
Palladium catalysts supported on functionalized multi-wall carbon nanotubes were synthesized for hydro-purification of crude terephthalic acid containing 2100ppm 4-carboxybenzaldehyde (4-CBA) as impurity. PdCl2 and Pd(OAc)2 were used as precursors. Palladium loadings were 0.05 to 0.6wt.% with catalysts reduced at 200 to 400°C. Catalysts prepared from both precursors with least 0.3wt.% palladium resulted in 99%+ removal of 4-CBA. The most desired selectivity was obtained for the catalyst with PdCl2 as precursor, reduction temperature of 300°C, and palladium loading of 0.3wt.%. This catalyst had slightly better performance than the commercial catalyst (0.5wt.% of palladium on activated carbon)...
Hydro-purification of crude terephthalic acid using palladium catalyst supported on multi-wall carbon nanotubes, Article Journal of Industrial and Engineering Chemistry ; Volume 28 , August , 2015 , Pages 202-210 ; 1226086X (ISSN) ; Khorasheh, F ; Rashidi, A. M ; Safekordi, A. A ; Sharif University of Technology
Korean Society of Industrial Engineering Chemistry 2015
Palladium catalysts supported on functionalized multi-wall carbon nanotubes were synthesized for hydro-purification of crude terephthalic acid containing 2100ppm 4-carboxybenzaldehyde (4-CBA) as impurity. PdCl
2 and Pd(OAc) 2 were used as precursors. Palladium loadings were 0.05 to 0.6wt.% with catalysts reduced at 200 to 400°C. Catalysts prepared from both precursors with least 0.3wt.% palladium resulted in 99%+ removal of 4-CBA. The most desired selectivity was obtained for the catalyst with PdCl 2 as precursor, reduction temperature of 300°C, and palladium loading of 0.3wt.%. This catalyst had slightly better performance than the commercial catalyst (0.5wt.%...
Polyoxometalate-supported Pd nanoparticles as efficient catalysts for the Mizoroki-Heck cross-coupling reactions in PEG medium, Article Applied Organometallic Chemistry ; Volume 34, Issue 1 , 2020 ; Hosseini, H ; Salami, R ; Sharif University of Technology
John Wiley and Sons Ltd 2020
Palladium nanoparticles supported on polyoxometalate as a solid carrier were successfully prepared and evaluated as a heterogeneous nanocatalyst for the Mizoroki-Heck cross-coupling reactions. This supported catalyst was characterized by a set of techniques, including XRD, chemical analysis (ICP-OES), IR spectroscopy, TEM and FE-SEM analyses. Poly (ethylene glycol) was employed as an environmentally friendly solvent for coupling reactions. The various fundamental reaction parameters that influence the efficiency of the reaction and yield of the desired reaction products were optimized. This catalytic system showed good activities and evolve a strategy for achieving five times catalyst and...
Rosmarinus officinalis directed palladium nanoparticle synthesis: Investigation of potential anti-bacterial, anti-fungal and Mizoroki-Heck catalytic activities, Article Advanced Powder Technology ; Volume 31, Issue 4 , 2020 , Pages 1402-1411 ; Bagherzadeh, M ; Kiani, M ; Ghadiri, A. M ; Sharif University of Technology
Elsevier B.V 2020
The present work was aimed to account a green and eco-friendly synthesis of palladium nanoparticles using Rosmarinus officinalis leaves extracts for the first time, therefore, that can be an acceptable replacement for chemical media to improve potential biological properties. The synthesized palladium nanoparticles were fully characterized using FT-IR, XRD, FESEM, TEM and UV/Vis spectroscopy techniques. Catalytic activity was investigated by Mizoroki-Heck reaction, and optimized based on solvent, temperature and time of the reaction, and the best results were found in water as a green media without any additional reagents. Biological activity of the synthesized nanoparticles were evaluated...
Improving Hydrogen Sensing by Adding Additives in Nanostructure WO3 Films, M.Sc. Thesis Sharif University of Technology ; Iraji Zad, Azam ; Mahdavi, Mohammad
The present work emphasizes on hydrogen resistance- sensing properties of WO3 films prepared by Sol-gel routs. The sol-gel is a simple and low cost rout which makes film with high homogeneity and low processing temperature .To improve Hydrogen sensing we modified WO3 films with Pd catalysts by Sol-gel and Electroless methods. AFM , EDX, SEM , XPS , XRD , were applied to analyze structure, morphology and Chemical composition of the fabricated thin films. We measured resistance sensing behavior of prepared films in exposure to different concentration of Hydrogen. All the films were tested under the same conditions. We measured resistance sensing in exposure to concentration below 10000 ppm...
Synthesis of Palladium Nanowires for Hydrogen Gas Sensor by Field Ionization, M.Sc. Thesis Sharif University of Technology ; Irajizad, Azam
The interesting properties of metallic nanowires provide many applications in electronic sensors. In this project, we have synthesized Pd nanowires using electrodeposition method. These nanowires are useful for hydrogen sensors by measuring field ionization current in gas. In this project, Pd nanowires were synthesized by electrochemical deposition method in PCT template with 100 nm pore size. The used solution was contained 2mM PdCl2 + 0.1M HCl. The best reduction potential was determined about -0.2V and the best time for synthesizing nanowires was 7 minutes. Chronoampermetric diagrams showed four steps, capacitive current, growth in the holes, reaching to the surface of PCT and the growth...
Supported Pd nanoparticles on Mn-based metal-organic coordination polymer: Efficient and recyclable heterogeneous catalyst for Mizoroki-Heck cross coupling reaction of terminal alkenes, Article Inorganic Chemistry Communications ; Vol. 44 , 2014 , Pages 10-14 ; ISSN: 13877003 ; Ashouri, F ; Hashemi, L ; Morsali, A ; Sharif University of Technology
Supported palladium nanoparticles on Mn-carboxylate coordination polymer (Pd/MnBDC) were prepared using solution impregnation method. This new catalyst was characterized by XRD, SEM, TEM, EDX, XPS, FTIR and TGA analysis. The Pd/MnBDC exhibits efficient catalytic activity for the Mizoroki-Heck coupling reaction between iodobenzene and either aromatic or aliphatic terminal alkenes and reuses up to four runs without significant loss of activities