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Reductive coupling reaction of benzyl, allyl and alkyl halides in aqueous medium promoted by zinc
, Ana C. P. F. de;Pontes, Giovanna M. A.;Anjos, José A. L. dos;Santana, Sidney R.;Bieber, Lothar W.;Malvestiti, Ivani;
Journal of the Brazilian Chemical Society , 2003, DOI: 10.1590/S0103-50532003000300015
Abstract: organic halides undergo reductive dimerization (wurtz-type coupling) promoted by zinc at room temperature in aqueous medium. the reaction yields are strongly enhanced by copper catalysis. this coupling procedure provides an efficient and simple method for the homocoupling of benzylic and allylic bromides and primary alkyl iodides.
Reductive coupling reaction of benzyl, allyl and alkyl halides in aqueous medium promoted by zinc  [cached]
Sá Ana C. P. F. de,Pontes Giovanna M. A.,Anjos José A. L. dos,Santana Sidney R.
Journal of the Brazilian Chemical Society , 2003,
Abstract: Organic halides undergo reductive dimerization (Wurtz-type coupling) promoted by zinc at room temperature in aqueous medium. The reaction yields are strongly enhanced by copper catalysis. This coupling procedure provides an efficient and simple method for the homocoupling of benzylic and allylic bromides and primary alkyl iodides.
An Electrochemical Synthesis of Functionalized Arylpyrimidines from 4-Amino-6-Chloropyrimidines and Aryl Halides  [PDF]
Stéphane Sengmany,Erwan Le Gall,Eric Léonel
Molecules , 2011, DOI: 10.3390/molecules16075550
Abstract: A range of novel 4-amino-6-arylpyrimidines has been prepared under mild conditions by an electrochemical reductive cross-coupling between 4-amino-6-chloro-pyrimidines and functionalized aryl halides. The process, which employs a sacrificial iron anode in conjunction with a nickel(II) catalyst, allows the formation of coupling products in moderate to high yields.
Electrochemical oxidation of oxalic acid in the presence of halides at boron doped diamond electrode
Martínez-Huitle, C. A.;Ferro, S.;Reyna, S.;Cerro-López, M.;De Battisti, A.;Quiroz, M. A.;
Journal of the Brazilian Chemical Society , 2008, DOI: 10.1590/S0103-50532008000100021
Abstract: aim of this work is to discuss the electrochemical oxidation of oxalic acid (oa), analyzing the influence of nacl and nabr. experiments were carried out at boron-doped diamond (bdd) electrodes, in alkaline media. bdd electrodes have a poor superficial adsorptivity so their great stability toward oxidation allows the reaction to take place with reactants and intermediates in a non-adsorbed state. the process is significantly accelerated by the presence of a halogen salt in solution; interestingly, the mediated process does not depend on applied current density. based on the results, bromide was selected as a suitable mediator during oa oxidation at bdd. br- primarily acts in the volume of the solution, with the formation of strong oxidants; while cl- action has shown lower improvements in the oa oxidation rate at bdd respect to the results reported using pt electrode. finally, the parameters of removal efficiency and energy consumption for the electrochemical incineration of oa were calculated.
EIS tests of electrochemical behaviour of Ti6Al4V and Ti6Al7Nb alloys  [PDF]
A. Baron,W. Simka,W. Chrzanowski
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: This study has been undertaken in order to establish the influence of parameters of the electrochemical treatment of Ti –alloys on their electrochemical behaviour in Tyrod solution.Design/methodology/approach: Surface of the Ti-alloys: Ti6Al4V and Ti6Al7Nb in the form of a rod submitted to grounding, electropolishing and anodic passivation. Electrochemical investigations were carried out by means of the electrochemical impedance spectroscopy method. Scope of this paper includes analysis of the impedance spectra based on Bode plot.Findings: Prolongation time of anodic passivation to 60 minutes caused formation of a two – layer model consisting of an inner layer which is compact and the barrier type, and outer layer which is porousResearch limitations/implications: Obtained results are the basis for the optimization of anodic passivation pareameters of the Ti alloys as a metallic biomaterial. The future research should be focused on selected more suitable parameters of the electrochemical impedance spectroscopy test to better describe process on the solid/ liquid interface.Practical implications: It has been found that a good resistance to corrosion and homogenous oxide layer on the Ti6Al4V and Ti6Al7Nb alloys surface can be achieved due to the application of electrolytic polishing of these alloys in a special bath and anodic passivation in sulphuric acid (VI), phosphoric acid (V) and inorganic salts.Originality/value: Results of the experiments presents the influence of various conditions of anodic passivation of the surface of the Ti6Al4V and Ti6Al7Nb alloy. In this cases, when the surface roughness plays important role, this method can be applied in treatment of the material intended for medical applications especially.
Electrochemical polymerization of furfural on a platinum electrode in aqueous solutions of potassium biphthalate
Hallal, Jorge Luiz Joaquim;Lucho, Alzira Maria Serpa;Gon?alves, Reinaldo Sim?es;
Materials Research , 2005, DOI: 10.1590/S1516-14392005000100006
Abstract: three different electrochemical methods confirm the growth processes of polyfurfural on platinum electrodes in aqueous solutions. the electrochemical oxidative polymerization of furfural occurs only with 0.10 mol l-1 potassium biphthalate as the supporting electrolyte. electrochemical and spectroscopic methods are employed to characterize the polymeric film produced. based on spectroscopic data, a polymeric structure involving furfural and biphthalate anions is discussed.
ELECTROCHEMICAL BEHAVIOUR AND VOLTAMMETRIC DETERMINATION OF GESHOIDIN AND ITS SPECTROPHOTOMETRIC AND ANTIOXIDANT PROPERTIES IN AQUEOUS BUFFER SOLUTIONS
Hailemichael Alemu, Berhanu M. Abegaz, Merhatibeb Bezabih
Bulletin of the Chemical Society of Ethiopia , 2007,
Abstract: The electrochemical behaviour of Geshoidin was investigated at a glassy carbon electrode in mixtures of citric acid and di-sodium hydrogen orthophosphate aqueous buffer system over a wide pH range (pH 2-11) using cyclic voltammetry. Chemically irreversible single oxidation and reduction peaks were obtained in the potential and pH range investigated. Variations in the peak potential and peak current of the oxidation peak have been observed as function of pH. The wave characteristics, the reversibility of the reactions, the diffusion coefficient and the number of electrons transferred have been studied. Linear sweep voltammetry was applied for the voltammetric determination of Geshoidin and a linear calibration curve over the range 1.00 x 10-6 - 1.00 x 10-4 M Geshoidin was achieved. The detection limit was found to be 5.00 x 10-7 M Geshoidin. For eight successive determinations of 1 x 10-5 M Geshoidin, a relative standard deviation (RSD) of 3.2 % was obtained. The voltammetric method was applied to the direct determination of Geshoidin in Gesho. The absorption spectra of Geshoidin are interpreted in terms of structural changes caused by protonation and deprotonation of the molecule as a result of changes in pH. The pKa values of the compound have been determined from the voltammetry and spectrophotometry measurements. The superoxide anion scavenging ability of Geshoidin was examined by differential pulse voltammetry and its antioxidant activity has been compared with natural antioxidants. KEY WORDS: Gesho, Geshoidin, Rhamnus prionoides, Electrochemical behaviour, Voltammetric determination, Spectrophotometry, Antioxidant activity Bull. Chem. Soc. Ethiop. 2007, 21(2), 189-204.
Efficient and convenient oxidation of benzyl halides to carbonyl compounds with Sodium nitrate and Acetic acid by phase transfer catalysis in aqueous media
Yu Lin Hu, Wei Wei, Qi Fa Liu, Ming Lu
Bulletin of the Chemical Society of Ethiopia , 2010,
Abstract: A variety of benzyl halides were converted to the corresponding aldehydes/ketones in good to high yields by phase transfer catalysis combined with sodium nitrate and acetic acid at reflux. As a result, a simple and high yield procedure has been developed. KEY WORDS: Oxidation, Benzyl halides, Phase transfer catalyst, Sodium nitrate Bull. Chem. Soc. Ethiop. 2010, 24(2), 277-282.
Environmentally Benign Electrophilic Halogenation of Naphthalenes by H2O2—Alkali Metal Halides in An Aqueous Cationic Micellar Media  [PDF]
Kancharla Rajendar Reddy, Sariah Sana, Kusampally Uppalaiah, Kamatala Chinna Rajanna, Puppala Veerasomaiah
International Journal of Organic Chemistry (IJOC) , 2012, DOI: 10.4236/ijoc.2012.23034
Abstract: An efficient and greener protocol for the synthesis of 1-halo-naphthols by the action of hydrogen peroxide and alkali metal halides in aqueous micellar media is been described in the present work. This is an environmentally clean and safe procedure, which involved insitu generation of the active halogen in presence of alkali halides. Cationic surfactants such as cetyltrimethylammoniumbromide (CTAB) and cetyltrimethylammoniumchloride (CTAC) were found to facilitate efficiency of halogenation in aqueous media.
Corrosive-Wear Behavior of Mo Modified Ti6Al4V Alloy by Wear-Electrochemical Noise Method
摩擦-电化学噪声法研究Mo改性钛合金的腐蚀-磨损行为

ZHANG Min,MA Yong,ZHANG Xiang-yu,FAN Ai-lan,TANG Bin,
张敏
,马永,张翔宇,范爱兰,唐宾

摩擦学学报 , 2012,
Abstract: The Mo surface modified layer on Ti6Al4V substrate is obtained by plasma surface alloying. The structure and composition of the Mo surface modified layer are investigated by X-ray diffraction (XRD) and glow discharge optical emission spectroscopy. The duplex Mo modified layer contains a pure Mo coating on subsurface and diffusion layers between the subsurface and substrate. XRD analysis of the Mo modified layer reveals that a Mo phase exists in the modified layer with <110> and <211> orientations in the subsurface. Corrosion-wear behaviors of Ti6Al4V substrate and Mo modified Ti6Al4V alloy sliding against corundum are investigated with the wear-electrochemical noise technique in a 0.5mol/L NaCl solution. Results indicate that the Mo modified layer improves the antiwear and friction reduction properties of Ti6Al4V. Moreover, the Mo modified layer improves self-corroding electric potentials and decrease the current of Ti6Al4V. The Mo modified layer can improve the corrosion-wear behavior of Ti6Al4V.
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