Loading...
Search for: molybdenum
0.006 seconds
Total 171 records

    Molybdenum(VI)-oxodiperoxo complex containing an oxazine ligand: Synthesis, X-ray studies, and catalytic activity

    , Article Journal of Coordination Chemistry ; Vol. 67, issue. 8 , Jul , 2014 , pp. 1429-1436 ; ISSN: 00958972 Amini, M ; Bagherzadeh, M ; Atabaki, B ; Derakhshandeh, P. G ; Ellern, A ; Woo, L. K ; Sharif University of Technology
    Abstract
    A new mononuclear molybdenum(VI)-oxodiperoxo complex [MoO(O 2)2(phox)] with a simple bidentate ligand, 2-(2′-hydroxyphenyl)-5,6-dihydro-1,3-oxazine (Hphox), has been synthesized and characterized by X-ray structure analysis, elemental analysis, infrared, and 1H NMR spectroscopy. A triclinic space group P-1 was determined by X-ray crystallography from single-crystal data of this complex. The resulting complex functioned as a facile sulfide oxidation catalyst with urea hydrogen peroxide as terminal oxidant at room temperature. The catalyst showed efficient reactivity in oxidation of sulfides giving high yield and selectivity  

    Synthesis, characterization, and catalysis of recyclable new piperazine-bridged Mo(VI) polymers [MoO 2(Salen)(piperazine)] n in highly selective oxygenation of alkenes and sulfides

    , Article Journal of Coordination Chemistry ; Volume 66, Issue 16 , 2013 , Pages 2885-2900 ; 00958972 (ISSN) Bagherzadeh, M ; Zare, M ; Sharif University of Technology
    2013
    Abstract
    This study reports synthesis and characterization of polymeric [MoO2(Salen)] complexes that combine MoO2(acac)2 and polymeric ligands bearing N2O2 coordination sites, abbreviated herein as [piperazinCH2{MoO2(Salen)}]n (6), [piperazinCH2{MoO2(Salophen)}]n (7), and [piperazinCH2{MoO2(Salpn)}]n (8). The epoxidation of alkenes using tert-butyl hydroperoxide and oxidation of sulfides to sulfoxides by urea hydrogen peroxide were enhanced with excellent selectivity under the catalytic influence of these coordination polymers. No relevant difference in activity was found due to change in the diamine in the Schiffs base ligands. The stability of polymeric catalysts was assessed by recycling a sample... 

    Oxido-peroxido molybdenum(VI) complexes in catalytic and stoichiometric oxidations

    , Article Coordination Chemistry Reviews ; Volume 257, Issue 7-8 , April , 2013 , Pages 1093-1121 ; 00108545 (ISSN) Amini, M ; Haghdoost, M. M ; Bagherzadeh, M ; Sharif University of Technology
    2013
    Abstract
    This review mainly discusses the application of oxido-peroxido Molybdenum(VI) complexes as catalysts or mediators in homogeneous or heterogeneous catalytic systems for oxidations of olefins, sulfides, alcohols, alkanes, and amines toward the synthesis of a variety of organic compounds, such as epoxides, sulfoxides, aldehydes and ketones, carboxylic acids, alcohols and nitroso compounds  

    Catalytic efficiency of a novel complex of oxoperoxo molybdenum(VI): Synthesis, X-ray structure and alkane oxidation

    , Article Inorganic Chemistry Communications ; Volume 15 , January , 2012 , Pages 52-55 ; 13877003 (ISSN) Bagherzadeh, M ; Amini, M ; Ellern, A ; Woo, L. K ; Sharif University of Technology
    Abstract
    A new mononuclear oxo-peroxo complex of molybdenum(VI) of the formula [MoO(O2)(phox)2] (where phox = 2-(2′-hydroxyphenyl) oxazoline) has been synthesized and characterized by X-ray structure analysis, elemental analysis, infrared, UV-visible and 1H, 13C NMR spectroscopy. A monoclinic space group P-1 was determined by X-ray crystallography from single-crystal data of this complex. Complex functions as facile alkane oxidation catalyst with hydrogen peroxide as terminal oxidant at room temperature. The catalyst shows very much efficient reactivity in the oxidation reactions giving high yield, turnover number (TON) and selectivity  

    Synthesis, structural characterization, and catalytic reactivity of a new molybdenum(VI) complex containing 1,3,4-thiadiazole derivative as a tridentate NNO donor ligand

    , Article Journal of Coordination Chemistry ; Volume 68, Issue 3 , Jan , 2015 , Pages 548-559 ; 00958972 (ISSN) Moradi Shoeili, Z ; Zare, M ; Bagherzadeh, M ; Kubicki, M ; Boghaei, D. M ; Sharif University of Technology
    Taylor and Francis Ltd  2015
    Abstract
    A new cis-dioxo molybdenum(VI) complex was obtained by reaction of 2,4-dihydroxybenzylidene(5-N,N-methylphenylamino-1,3,4-thiadiazol-2-yl)hydrazone as ligand and [MoO2(acac)2] in methanol and was characterized by elemental analyses, 1H NMR, IR, and electronic spectroscopic studies. The complex was also analyzed by single-crystal X-ray diffraction. The structure determination revealed a distorted octahedral coordination geometry around molybdenum in which the tridentate NNO donor (L2-) is bonded to [MoO2]2+ through phenolic oxygen, hydrazinic nitrogen, and thiadiazole nitrogen. The sixth coordination site is occupied by a weakly bonded methanol. The complex was tested as a catalyst for... 

    Immobilization of dioxomolybdenum(VI) schiff base complex on graphene oxide nanosheets and its catalytic activity for oxidation of sulfides

    , Article Journal of Coordination Chemistry ; Volume 70, Issue 17 , 2017 , Pages 2986-2998 ; 00958972 (ISSN) Bagherzadeh, M ; Karimi, H ; Amini, M ; Sharif University of Technology
    Abstract
    Graphene oxide was an effective supporting material for immobilizing a dioxomolybdenum Schiff base complex via covalent interaction. The large surface of graphene oxide plays important roles to obtain a good degree of catalytic reaction. Catalytic capacity of the graphene-bound dioxomolybdenum Schiff base complex was investigated for the oxidation of various sulfides to sulfoxide compounds using hydrogen peroxide urea as an oxidant. The catalyst was characterized by various techniques including XRD, FTIR, TGA, SEM, UV–vis, and ICP-AES. The immobilized complex was very efficient with the extra benefits of easy recovery and recycling of the heterogeneous catalyst. The graphene oxide bound... 

    Nanocluster polyoxomolybdate supported on natural zeolite: A green and recyclable catalyst for epoxidation of alkenes

    , Article Journal of Coordination Chemistry ; Volume 70, Issue 13 , 2017 , Pages 2212-2223 ; 00958972 (ISSN) Bagherzadeh, M ; Hosseini, H ; Sharif University of Technology
    Taylor and Francis Ltd  2017
    Abstract
    A heterogeneous catalyst for epoxidation of alkenes has been synthesized by introducing polyoxomolybdate into a natural zeolite as a solid and green support. The prepared catalyst was characterized by FT-IR, inductively coupled plasma optical emission spectrometry (ICP-OES), powder X-ray diffraction (XRD), N2 absorption–desorption, field emission scanning electron micrograph (FE-SEM) and transmission electron microscopy (TEM). The catalytic investigations disclosed that nanocluster polyoxomolybdate supported on the surface is an active and recyclable catalyst in liquid phase alkene epoxidation in dichloroethane at 80 °C. © 2017 Informa UK Limited, trading as Taylor & Francis Group  

    Diastereoselective synthesis and catalytic activity of two chiral cis-dioxidomolybdenum(VI) complexes

    , Article European Journal of Inorganic Chemistry ; Volume 2018, Issue 22 , 15 June , 2018 , Pages 2549-2556 ; 14341948 (ISSN) Haghdoost, M. M ; Zwettler, N ; Golbaghi, G ; Belaj, F ; Bagherzadeh, M ; Schachner, J. A ; Mosch Zanetti, N. C ; Sharif University of Technology
    Wiley-VCH Verlag  2018
    Abstract
    Two enantiomerically pure chiral dioxidomolybdenum(VI) complexes (1 and 2) of the type [MoO2L] (L = dianionic, tetradentate ONNO-ligand) were synthesized and investigated in enantioselective oxidation reactions. The solid-state structures of complex 1 and 2, determined via single-crystal X-ray diffraction analysis revealed two fundamentally different coordination geometries: a C1-symmetric cis-β isomer (Λ-1), and a C2-symmetric cis-α isomer (Δ-2). In both cases, only one of the two possible helical enantiomers (Λ- or Δ-helix) was formed. The complexes were examined as precatalysts in the epoxidation of the challenging prochiral substrate trans-stilbene, using either tert-butyl hydroperoxide... 

    Synthesis and cation-exchange behavior of expanded MoS2 nanosheets for anticorrosion applications

    , Article 2017 INN International Conference/Workshop on Nanotechnology and Nanomedicine, NTNM 2017, 2 May 2017 through 3 May 2017 ; Volume 5, Issue 7 , 2018 , Pages 15573-15579 ; 22147853 (ISSN) Haddadi, S. A ; Amini, M ; Ghaderi, S ; Ramazani, A ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Molybdenum disulfide (MoS2), a 2D layered structure, because of its unique properties has widely attracted many researchers. In this study, by employing physical and chemical methods, not only layers of MoS2 have been intercalated, but also their surface properties enhanced. Low-dimensional and potential properties of intercalated MoS2 nanosheets are the aim of many researches. Here, we report a novel four step method to intercalate the layers of MoS2 nanosheets successfully using acid treatment, sonication, oxidization and thermal shocking. The other goal in this study is to evaluate the cation exchange ability and anticorrosion performance of the Ce3+ doped MoS2 nanosheets. The... 

    cis-Dioxo-molybdenum(VI)-oxazoline complex catalyzed epoxidation of olefins by tert-butyl hydrogen peroxide

    , Article Inorganica Chimica Acta ; Volume 362, Issue 10 , 2009 , Pages 3698-3702 ; 00201693 (ISSN) Bagherzadeh, M ; Tahsini, L ; Latifi, R ; Keith Woo, L ; Sharif University of Technology
    2009
    Abstract
    A new efficient catalytic system was investigated for the epoxidation of various olefins by cis-dioxo-bis[2-(2′-hydroxyphenyl)-oxazolinato]molybdenum(VI), cis-[MoO2(phox)2], and TBHP as oxidizing agent. Using this system as catalyst for the oxidation of aliphatic substrates at 80 °C gives the epoxide as the sole product with yields up to 100% and turnover frequency up to 5000 h-1. The efficiency of the catalyst is strongly influenced by the nature of solvent, reaction time and temperature, and a significant increase in the epoxide yields is observed in higher temperatures and longer reaction times. © 2009 Elsevier B.V  

    Breakthrough curves for adsorption and elution of rhenium in a column ion exchange system

    , Article Hydrometallurgy ; Volume 85, Issue 1 , 2007 , Pages 17-23 ; 0304386X (ISSN) Mozammel, M ; Sadrnezhaad, S. K ; Badami, E ; Ahmadi, E ; Sharif University of Technology
    2007
    Abstract
    Impure rhenium and molybdenum bearing solution was passed through a column of Varian strong base anionic resin for selective adsorption of rhenium and molybdenum ions from the solution. Elution of molybdenum and rhenium was carried out using 2 N NaOH and 0.2 N NH4SCN, respectively. The effect of resin bed height on breakthrough time was investigated. Experimental and theoretical curves were compared with good agreement. The results showed that the behavior pattern of these curves was repeatable and almost constant. © 2006 Elsevier B.V. All rights reserved  

    Dioxo and oxo-peroxo molybdenum(VI) complexes bearing salicylidene 2-picoloyl hydrazone: Structures and catalytic performances

    , Article Polyhedron ; Volume 53 , 2013 , Pages 223-229 ; 02775387 (ISSN) Bagherzadeh, M ; Zare, M ; Amani, V ; Ellern, A ; Keith Woo, L ; Sharif University of Technology
    2013
    Abstract
    Molybdenum complexes bearing a salicylidene 2-picoloyl hydrazone ligand have been synthesized and characterized. The salicylidene 2-picoloyl hydrazone ligand (H2sal-phz) was prepared by reaction of picoloyl hydrazine with salicylaldehyde. Reaction of H2sal-phz with MoO2(acac) 2 generates the dioxo molybdenum complex MoO2(sal-phz) (CH3OH). Treatment of MoO3 in the presence of H 2O2 with H2sal-phz produces the oxo-peroxo molybdenum(VI) complex MoO(O2)(sal-phz)(CH3OH). The new compounds were characterized by 1H NMR and IR spectroscopies, and elemental analysis. The complexes were also characterized by single crystal X-ray diffraction crystallography. The complexes were evaluated for epoxidation... 

    Molybdenum oxo-peroxo complex: A very fast catalyst for oxidation and reduction of sulfur-based compounds

    , Article Catalysis Communications ; Volume 23 , June , 2012 , Pages 14-19 ; 15667367 (ISSN) Bagherzadeh, M ; Haghdoost, M. M ; Amini, M ; Derakhshandeh, P. G ; Sharif University of Technology
    2012
    Abstract
    We have evaluated the catalytic activity of a molybdenum(VI) oxo-peroxo complex through the oxidation and reduction of sulfur-based compounds. Arylalkyl, diaryl and dialkyl sulfides are selectively oxidized to corresponding sulfoxides, with tert-butyl hydroperoxide (TBHP), in the presence of MoO(O 2)(phox) 2 complex as catalyst. This molybdenum complex was also found to be an efficient catalyst for the deoxygenation of sulfoxides to sulfides with PPh 3 in excellent yields and chemoselectivity  

    Synthesis, X-ray structure and oxidation catalysis of a oxido-peroxido molybdenum(VI) complex with a tridentate Schiff base ligand

    , Article Inorganic Chemistry Communications ; Volume 20 , 2012 , Pages 86-89 ; 13877003 (ISSN) Bagherzadeh, M ; Amini, M ; Parastar, H ; Jalali Heravi, M ; Ellern, A ; Woo, L. K ; Sharif University of Technology
    2012
    Abstract
    A new oxido-peroxido molybdenum(VI) complex [MoO(O 2)L(CH 3OH)] was synthesized, using salicylidene benzoyl hydrazine as tridentate ONO donor Schiff base ligand (H 2L). The complex has been characterized by elemental analysis, IR, 1H NMR, molar conductance data, and finally by X-ray structure analysis. This complex functions as facile olefin epoxidation catalyst with hydrogen peroxide (H 2O 2) as terminal oxidant and sodium hydrogen carbonate (NaHCO 3) as a co-catalyst at room temperature. Catalytic potentiality of complex is also exhibited in oxidation of sulfides. The catalyst show very much efficient reactivity in the oxidation reactions giving high yield, turnover number (TON) and... 

    Synthesis, spectral characterization and crystal structure studies of a new hydrazone Schiff base and its dioxomolybdenum(VI) complex

    , Article Journal of Coordination Chemistry ; Volume 68, Issue 8 , Feb , 2015 , Pages 1441-1451 ; 00958972 (ISSN) Kia, R ; Kargar, H ; Sharif University of Technology
    Taylor and Francis Ltd  2015
    Abstract
    A new hydrazone-Schiff base (H2L) and it corresponding dioxomolybdenum(VI) complex were synthesized and characterized by spectroscopic methods and elemental analyses. The crystal structures of both ligand and its complex were determined by single-crystal X-ray diffraction. A new hydrazone Schiff base, (E)-N′-(3-ethoxy-2-hydroxybenzylidene)isonicotinohydrazide (H2L), has been prepared and characterized by elemental analyses, spectroscopic methods, and single-crystal X-ray diffraction. The corresponding dioxomolybdenum(VI) complex [Mo(O)2(L)(CH3OH)] was synthesized and characterized by spectroscopic methods and by single-crystal X-ray diffraction. The hydrazone ligand coordinates to Mo through... 

    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) Moradi Shoeili, Z ; 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  

    Synthesis, characterization and crystal structure of a dioxomolybdenum(VI) complex with a N,O type bidentate Schiff base ligand as a catalyst for homogeneous oxidation of olefins

    , Article Polyhedron ; Volume 28, Issue 12 , 2009 , Pages 2517-2521 ; 02775387 (ISSN) Bagherzadeh, M ; Latifi, R ; Tahsini, L ; Amani, V ; Ellern, A ; Keith Woo, L ; Sharif University of Technology
    2009
    Abstract
    The synthesis of a Mo(VI) Schiff base complex, cis-[MoO2{(4,6-bis(tert-butyl)-2-{(benzyl)iminomethyl}phenolate)2}], cis-[MoO2(L)2] where L = 4,6-bis(tert-butyl)-2-{(benzyl)iminomethyl}phenol, derived from benzylamine and 3,5-di-tert-butylsalycilaldehyde is reported. Full characterization of this complex was accomplished with elemental analyses, spectroscopic studies (NMR, IR and electronic) and X-ray structure analysis. This complex was tested as a catalyst for the homogeneous oxidation of olefins. The Mo(VI) complex is catalytically active for the epoxidation of aliphatic substrates at 80 °C, yielding the epoxide as the sole product in yields up to 100% and turnover numbers up to 5000.... 

    Synthesis and characterization of molybdenum complex supported on magnetic and non-magnetic supports: comparing their catalytic activity, selectivity, and reusability

    , Article Journal of the Iranian Chemical Society ; Volume 16, Issue 4 , 2019 , Pages 673-685 ; 1735207X (ISSN) Bagherzadeh, M ; Balali, M ; Haghdoost, M. M ; Keypour, H ; Sharif University of Technology
    Springer Verlag  2019
    Abstract
    A molybdenum complex was immobilized on Schiff-base-modified magnetic and non-magnetic particles by covalent linkage. The characterizations of the obtained materials were carried out by means of TG–DTG, SEM, TEM, VSM, XPS, IR, and Raman microprobe techniques. All of them exhibited efficient activities in the oxidation of sulfides to sulfoxides by urea hydrogen peroxide oxidant. The advantages and disadvantages of these catalysts are discussed in detail. Molybdenum complex immobilized on silica bead can be recycled and recovered by simple filtration, but it demonstrated low activity in catalytic oxidation reaction. Immobilization on nano-SiO 2 leads to the formation of nanocatalyst having... 

    Single-layer MoS2-MoO3-x heterojunction nanosheets with simultaneous photoluminescence and co-photocatalytic features

    , Article Catalysts ; Volume 11, Issue 12 , 2021 ; 20734344 (ISSN) Saadati, M ; Akhavan, O ; Fazli, H ; Sharif University of Technology
    MDPI  2021
    Abstract
    Single-layer MoS2-MoO3-x heterojunction nanosheets with visible-light-sensitive band gap energy and average lateral dimensions of ~70 nm were synthesized by using a two-step combined exfoliation method. The exfoliation was initiated from pristine MoS2, while some sulfur sites in expanded MoS2 sheets during exfoliating were substituted by ambient non-thermal oxygen, resulting in formation of α-MoO3-x crystalline domains. The morphological features, crystalline structure, phase formation, number of layers, and optical properties of the MoS2-MoO3-x nanosheets were determined by atomic force microscopy; X-ray diffraction; field emission electron microscopy; transmission electron microscopy; and... 

    Experimental study and correlation for mass transfer coefficient in the pilot plant multistage column with the presence of molybdenum

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 41, Issue 2 , 2022 , Pages 544-554 ; 10219986 (ISSN) Shakib, B ; Torab Mostaedi, M ; Outokesh, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
    Iranian Institute of Research and Development in Chemical Industries  2022
    Abstract
    In the present work, multistage extraction column performance for reactive separation of molybdenum from the leach aqueous phase by using D2EHPA and TBP in kerosene was investigated by using the axial diffusion model. The variation of volumetric overall mass transfer coefficients based on continuous phases at various operating conditions was obtained. By considering the chemical reaction conditions, the experimental data indicate that the volumetric overall mass transfer coefficients increase with an enhancement in rotor speed and continuous and dispersed phase flow rates. According to the sensitivity analysis, the rotor speed and flow rate of the dispersed phase have more influence on...