نتایج جستجو برای: catalyst, magnetic

تعداد نتایج: 381387  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1392

a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...

Journal: :journal of nanostructures 2015
h. khojasteh v. mirkhani m. moghadam s. tangestaninejad i. mohammadpoor-baltork

palladium is the best metal catalyst for suzuki cross coupling reaction for synthesize of unsymmetrical biaryl compounds. but its high cost limits its application in wide scale. using of nanoscale particles as active catalytic cites is a good approach for reducing needed noble metal. by loading precious nanoparticles on magnetic nanocores as a support, recycling and reusing of catalyst will be ...

Journal: :organic chemistry research 2015
elahe yazdani kobra azizi athar nakisa akbar heydari*

we have reported the fabrication of boric acid incorporated into surface of magnetite nanoparticles. the catalyst was characterized using spectroscopic, magnetic and thermal techniques (ft-ir, sem, xrd, icp, vsm and tga). it catalyzed mukaiyama aldol reaction of a ketene silyl acetal type nucleophile ((1-methoxy-2-methylprop-1-enyloxy) trimethylsilane), and various aldehydes (aromatic, aliphati...

H. Khojasteh, I. Mohammadpoor-Baltork M. Moghadam S. Tangestaninejad V. Mirkhani

Palladium is the best metal catalyst for Suzuki cross coupling reaction for synthesize of unsymmetrical biaryl compounds. But its high cost limits its application in wide scale. Using of nanoscale particles as active catalytic cites is a good approach for reducing needed noble metal. By loading precious nanoparticles on magnetic nanocores as a support, recycling and reusing of catalyst will be ...

Journal: :iranian journal of catalysis 2013
bijan mombani godajdar ali reza kiasat

regarding the green chemistry's goals, dicationic magnetic room temperature ionic liquid open up new avenue to introduce an amazing and efficient system for facilitating catalyst recovery in different organic reactions. ability of this dicationic magnetic room temperature ionic liquid catalyst in the one-pot three-components condensation reaction of benzil, aromatic aldehyde, and ammonium aceta...

Journal: :nanochemistry research 1999
eshagh rezaee nezhad ezatallah pourmalekshahi

an efficient and simple method for the preparation of si-imidazole-hso4 functionalized magnetic fe3o4 nanoparticles (si-im-hso4 mnps) and used as an efficient and reusable magnetic catalysts for the regioselective ring opening of epoxides under green conditions in water. this catalyst was used for the ring opening of epoxide corresponding to the thiocyanohydrins and azidohydrines. compared to t...

Journal: :journal of sciences, islamic republic of iran 2015
m.j. taghizadeh a. javidan o. hosseinchi

a new magnetic nanocatalyst has been prepared using immobilization of vanadate onto aminopropyl functionalized sio2/fe3o4(vo3-/nh3+-sio2/fe3o4). the obtained magnetic catalyst was characterized by ft-ir, xrd, vsm and sem techniques and used for sulfoxidation of sulfide compounds to the correspondingsulfoxides in presence of h2o2 as oxidant at room temperature. the optimum of reaction conditions...

Journal: :nanochemistry research 2016
massomeh ghorbanloo amene mohamadi heidenori yahiro

bis-(l-tyrosinato)copper(ii) was reacted with 3-(chloropropyl)-trimethoxysilane functionalized silica that has infused magnetite to yield a magnetically separable catalyst in which the copper carboxylate is covalently linked to the silica matrix through the silane linkage. the immobilized catalyst has been characterized by spectroscopic studies (such as ft-ir, epr, magnetic measurement, sem) an...

Journal: :nanochemistry research 0
fariborz mansouri chemistry department, tarbiat modares university, tehran, iran mehdi sheykhan chemistry department, guilan university, rasht, iran akbar heydari chemistry department, tarbiat modares university, tehran, iran

a mild, green and highly efficient route for regio-selective amination of oxiranes was developed via incorporation of mn(ii), fe(ii), co(ii), ni(ii), cu(ii) and zn(ii) cations onto the surface of hydroxyapatite-encapsulated γ-fe2o3 nanoparticles (γ-fe2o3@hap). among six magnetically recoverable catalytic systems denoted as [γ-fe2o3@hap-mii], the catalyst in which m designated as fe(ii) showed t...

Journal: :iranian journal of catalysis 2016
javad safari leila javadian

in this paper, fe3o4-chitosan nanoparticles were prepared by the immobilization of chitosan on the surface of fe3o4 nanoparticles. then, the 5-substituted hydantoins were synthesized from the condensation of aldehyde derivatives, ammonium carbonate and zinc cyanide as a well-known cyanating agent by the magnetic fe3o4-chitosan nanoparticles under neat conditions. fe3o4-chitosan nanocatalyst as ...

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