scholarly journals Copper (II) Catalyzed Oxidative Alkoxylation of White Phosphorus. Communication 2.

2010 ◽  
Vol 12 (3,4) ◽  
pp. 267
Author(s):  
R.R. Abdreimova ◽  
F.Kh. Faizova ◽  
A.A. Karimova
Keyword(s):  
Metal Ion ◽  
Phosphorous Acid ◽  
White Phosphorus ◽  
Reduced Form ◽  
Molar Ratio ◽  
Main Reaction ◽  
Reaction Products ◽  
Dimethyl Phosphite ◽  
Trialkyl Phosphates ◽  
Oxidative Alkoxylation

White phosphorus has been catalytically oxidized by oxygen in alcoholic solutions of copper (II) acetylacetonate, halides or carboxylates to yield dialkyl phosphites and trialkyl phosphates under mild reaction conditions. Trialkyl phosphite has been observed as unstable organophosphorus intermediate, which is being converted into the main reaction products. In the case of methanolic solutions, the derivatives of two step acidolysis of dimethyl phosphite, monomethyl phosphite and phosphorous acid, have been additionally detected among the reaction products. The influence of the copper (II) catalysts on the kinetics of accumulation and transmutation of organophosphorus products has been explored. It has been found that the Cu(II) compounds take a role of catalysts-electron-carriers from white phosphorus to oxygen. The indispensable molar ratio between catalyst and white phosphorus and the order of catalytic activity for the copper (II) compounds have been established. The major steps of the catalytic reaction including (i) the coordination of white phosphorus and alcohol to metal ion, (ii) the redox decomposition of this intermediate complex accompanied by reducing elimination of elementary copper and formation of organophosphorus product and (iii) the oxidation of the reduced form of catalyst by oxygen have been<br />also suggested.

scholarly journals Copper (II) Mediated Oxidative Alkoxylation of White Phosphorus. Communication 1.

2010 ◽  
Vol 12 (3,4) ◽  
pp. 259
Author(s):  
R.R. Abdreimova ◽  
F.Kh. Faizova ◽  
A.A. Karimova
Keyword(s):  
Metal Ion ◽  
Phosphorous Acid ◽  
Inert Atmosphere ◽  
White Phosphorus ◽  
Main Reaction ◽  
Reaction Products ◽  
Dimethyl Phosphite ◽  
Trialkyl Phosphates ◽  
Oxidative Alkoxylation ◽  
Kinetics Of

White phosphorus has been oxidized by copper (II) acetylacetonate, halides or carboxylates in aliphatic alcohols to yield dialkyl phosphates and trialkyl phosphates under inert atmosphere and mild reaction conditions. Trialkyl phosphite has been observed as unstable organophosphorus intermediate, which is being converted into the main reaction products. In the case of methanolic solutions, the derivatives of two step acidolysis of dimethyl phosphite, monomethyl phosphite and phosphorous acid, have been additionally detected among the reaction products. The influence of the copper (II) oxidants on the kinetics of accumulation and transmutation of organophosphorus products has been explored. The order of oxidative ability of the copper (II) compounds has been established. The major steps of the reaction including (i) the coordination of white phosphorus and alcohol to metal ion and (ii) the redox decomposition of this intermediate complex accompanied by reducing elimination of elementary copper and formation of organophosphorus product have been also suggested.

Hydrogenolysis of Glycerol in Gas Phase on Cu-Cr Mixed Oxide Catalyst Doped with Ni

2017 ◽  
Vol 68 (5) ◽  
pp. 1118-1121
Author(s):  
Vasile Georgescu ◽  
Casen Panaitescu ◽  
Mihaela Bombos ◽  
Dorin Bombos
Keyword(s):  
Gas Phase ◽  
Propylene Glycol ◽  
Mixed Oxide ◽  
Oxide Catalyst ◽  
Molar Ratio ◽  
Main Reaction ◽  
Reaction Products ◽  
Glycerol Conversion ◽  
Mixed Oxide Catalyst ◽  
Temperature And Pressure

Hydrogenolysis of glycerol was conducted on catalyst of the type mixed oxide of Cu-Cr doped with NiO on g-Al2O3. The prepared catalyst was analyzed by XRD, IR and TPR. Catalytic tests were carried out on a laboratory plant in continuous flow system on a reactor equipped with heating mantle, at molar ratio of glycerol / hydrogen of 1/300, glycerol volume hourly space velocities 1000s-1, temperatures 200-220oC and pressures 3-5 bar. The main reaction products identified were propylene glycol and hydroxyacetone. Glycerol conversion increases with temperature and pressure on ranges of parameters studied. Selectivity to propylene glycol increases with increasing of temperature and pressure and the selectivity to hydroxyacetone decreases with increasing of temperature and pressure on the variation range of the parameters studied.

scholarly journals Catalytic Synthesis of the Esters of Phosphorus Acids from White Phosphorus and Aliphatic or Aromatic Alcohols

2017 ◽  
Vol 4 (1) ◽  
pp. 11 ◽  
Author(s):  
R.R. Abdreimova ◽  
F.Kh. Faizova ◽  
D.N. Akbayeva ◽  
G.S. Polimbetova ◽  
S.M. Aibasova ◽  
...  
Keyword(s):  
Metal Ion ◽  
Catalytic Efficiency ◽  
Side Reaction ◽  
White Phosphorus ◽  
Reduced Form ◽  
Radical Chain ◽  
Catalytic Systems ◽  
Variable Nature ◽  
Aromatic Alcohols ◽  
A Minor

<p>The various esters of the phosphoric and phosphorous acids have been obtained directly from white phosphorus and aliphatic (or aromatic) alcohols under aerobic atmosphere in the presence of the CuX<sub>2</sub> or FeX<sub>3</sub> (X = Cl, NO<sub>3</sub>, C<sub>3</sub>H<sub>7</sub>CO<sub>2</sub>) salts. Irrespective of the variable nature of the used alcohols and catalysts, trialkyl(aryl) phosphates and dialkyl phosphites are a major products, whereas trialkyl(aryl) phosphites and dialkyl phosphates are a minor products of the phosphorylation process. Thanks to the presence of catalysts, the possible side reaction route of the radical chain oxidation of white phosphorus by oxygen to phosphorus oxides has been precluded. A comparison between the catalytic properties of CuX<sub>2</sub> and FeX<sub>3</sub> has been done. Although both of them have been found an efficient catalysts for the syntheses, the Cu(II) salts are active at 50-65 °C, whereas the Fe(III) based catalytic systems become competitive in terms of catalytic efficiency when reaction is carried out at 70-90 °C. Aromatic alcohols are characterised by less reactivity in this catalytic reaction as compared with an aliphatic ones. The same coordinative redox mechanism of the oxidative P-O coupling of P<sub>4 </sub>to ROH in the presence of both Cu(II) and Fe(III) catalysts has been proposed. Relevant steps of the catalytic cycle including the complexation of both white phosphorus and alcohol molecules to metal ion, the reduction of catalyst by white phosphorus, and the oxidation of reduced form of catalyst by oxygen have been also considered.</p>

scholarly journals The oxidation of 4-bromacetophenone by ozone in acetic acid

2021 ◽  
pp. 37-42
Author(s):  
A. Galstyan ◽  
A. Bushuyev ◽  
A. Krasilnikova ◽  
M. Zhurba
Keyword(s):  
Acetic Acid ◽  
Acetic Acid Solution ◽  
Decisive Role ◽  
Reduced Form ◽  
Main Reaction ◽  
Side Chain ◽  
Reaction Products ◽  
Third Order ◽  
Chain Oxidation ◽  
High Concentrations

The kinetics and mechanism of oxidation of 4-bromoacetophenone by ozone in acetic acid solution have been studied. It was shown that 77% of the starting material is oxidized by the benzene ring; 8% of 4-bromobenzoic acid and small amounts of carbon (IV) oxide were identified among the side chain ozonation products. The main reaction products are aliphatic peroxide compounds, which have in their structure one hydroperoxide group. Manganese (II) acetate was shown to be the most effective catalyst for the side chain reaction of 4-bromoacetophenone in acetic acid. High selectivity for the side chain is achieved only at sufficiently high concentrations of catalyst ([Mn(OAc)2]0:[ArH]0=1:4). The main product of the catalytic oxidation of 4-bromoacetophenone is 4-bromobenzoic acid with a yield of 82.5%. The found dependences of the rate of oxidation of 4-bromoacetophenone by ozone on the concentration of reactants are described by the kinetic equation of the third order, the reaction rate has the first order with respect to each reagent. It was found that the decisive role in the selective oxidation of 4-bromoacetophenone is played by two-stage oxidation, in which ozone predominantly reacts with the reduced form of manganese, and the introduction of the substrate into side chain oxidation is carried out by the reaction with the oxidized form of metal. According to the research results, the mechanism of catalytic ozonation of 4-bromoacetophenone in acetic acid has been proposed, which involves ion-radical non-chain oxidation of the substrate.

Evidence for presence of a reduced form of digoxin-like immunoreactive factor (dihydro-DLIF) in mammalian tissues

1996 ◽  
Vol 42 (7) ◽  
pp. 1092-1099 ◽  
Author(s):  
H M Qazzaz ◽  
S A Jortani ◽  
J M Poole ◽  
R Valdes
Keyword(s):  
Lactone Ring ◽  
Fold Increase ◽  
Cross Reactivity ◽  
Reduced Form ◽  
Molar Ratio ◽  
Endogenous Ligand ◽  
Metabolic Route ◽  
Mammalian Tissues ◽  
Spectral Absorbance ◽  
Cytochrome P 450

Abstract Digoxin-like immunoreactive factor (DLIF) from adrenal glands is an endogenous ligand structurally related to the plant-derived cardiac glycoside digoxin. Cardiac glycosides regulate the activity of the sodium pump and thus play key roles in disease processes involving regulation of ion transport. We now report the discovery of an endogenous dihydro-DLIF analogous to dihydrodigoxin. We used HPLC, ultraviolet spectrophotometry, and cross-reactivity with two antibodies, one specific for digoxin and one for dihydrodigoxin, to support the hypothesis that dihydro-DLIF contains a chemically reduced lactone ring. The spectral absorbance maximum for dihydro-DLIF is at 196 nm, identical to dihydrodigoxin. DLIF and dihydro-DLIF are 975- and 2588-fold less immunoreactive than digoxin and dihydrodigoxin for their respective antibodies. The molar ratio of dihydro-DLIF to DLIF is approximately 5.3 in bovine adrenocortical tissue and approximately 0.38 in human serum. Dihydrodigoxin (reduced lactone ring) added to microsomes isolated from bovine adrenal cortex produced a 4.5-fold increase in digoxin-like immunoreactivity (oxidized lactone ring) after 3 h of incubation. The biotransformation is likely mediated by a cytochrome P-450 NADPH-dependent process. Our findings demonstrate the presence of a dihydro-DLIF in mammals and suggest a metabolic route for synthesis of endogenous DLIF in mammalian tissue.

Reuse of Fried Oil to Obtain Biodiesel: Zeolites Y as a Catalyst

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
A. Brito ◽  
M. E. Borges ◽  
R. Arvelo ◽  
F. Garcia ◽  
M. C. Diaz ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Weight Ratio ◽  
Degree Of Conversion ◽  
Transesterification Reaction ◽  
Molar Ratio ◽  
Catalytic Reactor ◽  
Reaction Products ◽  
Waste Oil ◽  
Catalytic Effects ◽  
Fried Oil

The transesterification reaction is the most utilized process to obtain biodiesel. Fried oil transesterification reactions with methanol have been studied using several zeolites Y and interchanged with CsCl and KOH. The reaction has been carried out both in a slurry reactor and a fixed bed catalytic reactor. The catalytic effects of zeolites have been tested within a temperature range of 60-476°C, 2.5-5% catalyst/waste oil weight ratio, and 6:1 - 100:1 methanol/oil molar ratio. Cosolvents (THF, n-hexane) in the reaction feedstock effect have also been studied as well as catalyst regeneration effects. Viscosity of both the oil and the transesterification reaction products was determined as an initial guide to investigate the degree of conversion to biodiesel as well as FAME content by GC. When interchanged zeolites are used conversions are improved, getting the best yields (98% FAME) for the Y756 zeolite interchanged with KOH. Viscosities of the reaction product obtained reached values next to diesel standard ones.

Experimental Study on a Double-Swirled Non-Premixed Humid Air/Syngas Burner

2013 ◽  
Author(s):  
Bing Ge ◽  
Shu-sheng Zang ◽  
Yinsheng Tian ◽  
Dong-fang Zhang ◽  
Yao-xin Cui ◽  
...  
Keyword(s):  
Power Generation ◽  
Nozzle Exit ◽  
Concentration Field ◽  
Cost Effective ◽  
Combined Cycle ◽  
Molar Ratio ◽  
Main Reaction ◽  
Oh Radicals ◽  
Integrated Gasification Combined Cycle ◽  
Coal Fuel

The development of integrated gasification combined cycle (IGCC) systems provides cost-effective and environmentally sound options for meeting future coal-utilizing power generation needs in the world. The combustion of gasified coal fuel significantly influences overall performance of IGCC power generation. Experimental measurements are carried out on a non-premixed model combustor, equipped with a double-swirled syngas burner. Planar laser-induced fluorescence (PLIF) of OH radical measurement is adopted to identify main reaction zones and burnt gas regions as well. Together with the temperature and emission measurements during the exhaust section, some important characteristics of the syngas flame are investigated overall. In this paper, the effects of the CO/H2 molar ratio consisting of syngas fuel are investigated under different humidity. With the increase of CO/H2 ratios, the concentration field of OH radicals is gradually away from the nozzle exit, and the nozzle exit almost no existence of OH radicals, forming a typical lifted flame. In addition, fluorescent signal strength of OH radicals pronounced weakening, the flame gradually appeared W type distribution and more and more obvious with the increased of humidification amount. At the same time the average exhaust temperature of combustor CO and NOx missions almost no change. The study can provide a reliable database for high moisture gas turbine combustor design and combustion numerical simulation.

One-Step Simultaneous Differential Scanning Calorimetry-FTIR Microspectroscopy to Quickly Detect Continuous Pathways in the Solid-State Glucose/Asparagine Maillard Reaction

2013 ◽  
Vol 96 (6) ◽  
pp. 1362-1364 ◽  
Author(s):  
Deng-Fwu Hwang ◽  
Tzu-Feng Hsieh ◽  
Shan-Yang Lin
Keyword(s):  
Differential Scanning Calorimetry ◽  
Solid State ◽  
Maillard Reaction ◽  
Reaction Pathway ◽  
Molar Ratio ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Scanning Calorimetry ◽  
Ftir Microspectroscopy ◽  
Amadori Product

Abstract The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.

scholarly journals Determination of the Ratios of Ligands to Metal Ion of some Metal Complexes of Triazoles by Using Eleetronie Speetra in Organie Solvents

2004 ◽  
Vol 1 (1) ◽  
pp. 110-115
Author(s):  
Baghdad Science Journal
Keyword(s):  
Solid State ◽  
Metal Complexes ◽  
Electronic Spectra ◽  
Metal Ion ◽  
The Other ◽  
Molar Ratio ◽  
Other Hand

We found that 4,5- diphenyl- 3(2- propynyl) thio- 1??-triazole [1? forms a complex with Pd (11) ion of ratio 1:1 which absorbs light in CH2CI2 at 400 nm, and 4,5- diphenyl- 3(2- propenyl) thio- 1,2,4- triazole [II] forms complexes with Pd (II) ion of ratio 1:1 which absorbs light at 390 nm, and of ratio 2:1 which absorbs light at 435 nm. On the other hand, we found that the new derivative 4- phenyl- 5( p- amino phenyl) -3- mercapto- 1,2,4- triazole ?111? forms complexes with Cu (II) ion of the ratio 1:1 which absorbs light at 380 nm, with Ni (II) ion of the ratio 3:1 which absorbs light at 358 nm; and with Co (11) ion of the ratio 3.2:1 which absorbs light at 588 nm. The ratio of the complexes were determined by measuring the electronic spectra of the complexes in CH2G2 and (CH^NCHO at different concentrations ofthe ligands and f?xed ' •' of the metal ion in every case, then applying the molar ratio plots on the data. Our results were confirmed by precipitating most ofthe above complexes in solid state, and then each complex was analyzed elementally.

scholarly journals Synthesis and Spectroscopic Characterization for Some Metal ion Complexes with 2-Hydroxy-3-((5-Mercapto-1,3,4-Thiadiazol-2-yl)Diazenyl)-1-Naphthaldehyde

2016 ◽  
Vol 13 (2) ◽  
pp. 105-114
Author(s):  
Baghdad Science Journal
Keyword(s):  
Metal Complexes ◽  
Metal Ion ◽  
Mass Spectra ◽  
Spectroscopic Characterization ◽  
Bidentate Ligand ◽  
Molar Ratio ◽  
Theoretical Treatment ◽  
Spectroscopic Techniques ◽  
Metal Ion Complexes ◽  
Square Planar

New metal ion complexes were synthesized with the general formula; K[PtLCl4], [ReLCl4] and K[ML(Cl)2] where M = Pd(II), Cd(II), Zn(II) and Hg(II), from the Azo ligand (HL) [2-Hydroxy-3-((5-mercapto-1,3,4-thiadiazol-2-yl)diazenyl)-1-naphth aldehyde] (HL) the ligand was synthesized from (2-hydroxy-1-naphthaldehyde) and (5-amino-1,3,4-thiadiazole-2-thiol). The ligand and its metal complexes are characterized by phisco- chemical spectroscopic techniques (FT.IR, UV-Vis and Mass spectra, elemental analysis, molar conductivity, Atomic Absorption, Chloride contain and magnetic susceptibility). The spectral data suggest that the (HL) behaves as a bidentate ligand in all complexes. These studies revealed tetrahedral geometries for all metal complexes, except square planar for Pd(II) complex and except octahedral geometry for Pt(IV) and Re(V) complexes. The study of complexes formation via molar ratio of (M:L) as (1:1). Theoretical treatment of this ligand and its metal complexes in gas phase using Hyper chem.8 was preformed.

Sign in / Sign up

Export Citation Format

Share Document