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  • 1980-1984  (3)
  • 1965-1969  (1)
  • 2-hydroxycyanoethane  (2)
  • Inorganic Chemistry  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 10 (1981), S. 757-774 
    ISSN: 1572-8927
    Keywords: Cu(II)/Cu(I) couple ; Cu(I)/Cu(0) couple ; acetonitrile-water mixtures ; Fe(III) ; 2-hydroxycyanoethane ; electrochemistry ; voltammetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrochemical characteristics of the Cu (II)/Cu (I) and the Cu (I)/Cu (0) couples at platinum, carbon, mercury and copper have been studied in acetonitrile-water (AN-H2O) mixtures. All the electrode processes are moderately fast with mercury the fastest but slower on platinum and carbon paste in that order. A slow chemical step precedes oxidation of Cu (I) to Cu (II) on allectrodes in solutions of high AN content. The slow step may be partial removal of AN from the solvated Cu (I) ion prior to electron transfer. Electrode processes are faster in chloride ions than in sulfate ion solutions. Reduction of Cu (I) in AN−H2O is quite slow on glassy carbon. Adsorption of AN on platinum and carbon influences the processes. Diffusion coefficients in sulfate solutions are in the order, Cu (I) (AN−H2O)〉Cu (II)(AN−H2O)〉Fe (III)(H2O) and 2-hydroxy-cyanoethane (2-HCE) strongly decreases the mobility of Cu (I) when added to H2O. The relevance of the measurements to hydrometallurgical processes is considered. CuSO4 in 30% v/v AN−H2O is a ‘faster’ oxidant than the common oxidant Fe2(SO4)3 in H2O because of the greater mobility and faster electron acceptance from a corroding surface of Cu (II). Only in solutions of very high nitrile content is the reduction potential of CuSO4 as high as that of Fe2(SO4)3 in H2O.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 11 (1982), S. 495-508 
    ISSN: 1572-8927
    Keywords: Thermodynamic transfer quantities ; acetonitrile ; pyridine ; 2-hydroxycyanoethane ; aqueous organic solvent mixtures ; Cu2+, Cu+, and Ag+ ions ; hydrometallurgy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Free energies and Walden products show that the Cu+ and Ag+ ions are specifically solvated by acetonitrile (AN), 2-hydroxycyanoethane (HAN), and by pyridine (Py) whereas Na+ is specifically solvated by water, in mixtures of these organics with water. The Cu2+ ion is specifically solvated by pyridine in pyridine-water mixtures, but by water in acetonitrile-water mixtures. Ion-solvent, coordinated solvent-bulk solvent, and solvent-solvent interactions produce large entropy losses in the order Cu+≫Ag+〉Na+ for transfer of these ions from water to dilute acetonitrile-water. The metallurgically important oxidations of copper, silver, CuS and Cu2 with CuSO4 in water are strongly favored in an enthalpic and free energy sense by the addition of acetonitrile, but addition of acetonitrile also produces a large loss of entropy for the reactions.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 349 (1967), S. 213-219 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Für die Hydrazin-Komplexe von Mn(II), Co(II), Ni(II), Cu(II) und Zn(II) werden Zusammensetzung und Bildungskonstanten nach der Methode von Rossotti und Rossotti ermittelt, wobei experimentell pH-Titrationen in Lösungen durchgeführt wurden, die Metall-perchlorat, Hydrazin-diperchlorat und Natriumperchlorat (Ionenstärke μ = 1, t = 30°C) enthalten. In entsprechender Weise wurden die Bildungskonstanten für die Protonisierung von Hydrazin bestimmt. Selbst bei den höchsten Verhältnissen: Gesamt-Hydrazin/Gesamt-Metall (etwa 60) haben die höchsten Komplexe nur bei Co(II) und Zn(II) das Verhältnis:Metall/Hydrazin = 1 : 2, während in allen anderen Fällen in Lösung nur 1 : 1-Komplexe zu existieren scheinen.Die Werte der Bildungskonstanten (30°C, μ = 1) siehe „Summary“.Die nach Bjerrum berechneten β1-Werte sind mit den gefundenen in recht guter Übereinstimmung mit Ausnahme für Co(II). Die Grenzen für die Bjerrum-Methode werden diskutiert.
    Notes: The compositions and formation-constants of the complexes formed by Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with hydrazine have been evaluated graphically following the method of Rossotti and Rossotti using the necessary data from the results of pH titration of solutions containing the metal perchlorate, hydrazinium diperchlorate and sodium perchlorate at an ionic strength of unity at 30°C. The values of the successive equilibrium constants for the protonation of hydrazine, which were also needed, have been evaluated separately by similar procedure. Even at the rather high ratio of ca. 60 of (total hydrazine)/(total metal) the highest complexes which appear to be formed in the systems investigated have the ratio of metal:hydrazine of 1:2 for Co(II) and Zn(II), while in all the other cases only 1: 1 complexes appear to exist in solution.The values of the formation-constants (at 30°C; μ = 1) obtained are: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l} \log \beta _1 :{\rm Mn(II), 4}{\rm .76; Co(II), 1}{\rm .78; Ni(II),3}{\rm .18; Cu(II),6}{\rm .67;Zn(II), 3,69}{\rm.} \\ \log \beta _2 :{\rm Co(II), 3}{\rm .34; Zn(II), 6}{\rm .69}. \\ \end{array} $$\end{document}β1 values obtained from the Bjerrum relation are in fairly good agreement with those given above except for Co(II). The limitations of Bjerrum's method are discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 461 (1980), S. 222-230 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Quantitative „Softness“ Parameter und ihre Anwendung in der Strukturaufklärung von Bimetalltetracyanat-Komplexen〉2M(NCS)2M′(SCN)2〈 und [Ml6][M′(SCN)4], (M = COII und NiII; M′ = ZnII, CdII und HgII, L = Anilin, p-Toluidin, Pyridin, Nicotinamid, 2,2′-Bipyridin und 4-Aminopyridin) wurden dargestellt und charackterisiert. Die Strukturen werden auf Grund von Leitfähigkeits-, magnetischen und spektroskopischen (IR und VIS) Messungen, sowie durch gruppentheoretische Berechnungen und Ligandenfeldparametern vorgeschlagen. Diese Strukturvorschläge werden gestützt durch quantitative „Softness“ - Werte „\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm E}_{\rm n}^{_ + ^ +},{\rm E}_{\rm m}^{_{\rm +}^{\rm +}} $\end{document}“. Die totale „Softness“ von M und M′ und ihre Differenz \documentclass{article}\pagestyle{empty}\begin{document}$ \Delta {\rm TE}_{\rm n}^{_ + ^ +} \left({{\rm M} - {\rm M}'} \right) $\end{document} wurden abgeleitet (Gleichungen siehe Abstract) und mit der Struktur der Komplexe in Verbindung gebracht.
    Notes: 〉2M(NCS)2M′(SCN)2〈 and [ML6][M′(SCN)4], (M = Co(II) and Ni(II), M′ = Zn(II), Cd(II) and Hg(II) and L = aniline(ani), p-toluidine(tol), pyridine(py), nicotinamide(nia), 2,2′-bipyridine(bipy) and 4-aminopyridine (apy)) have been prepared and characterized. Their structure have been proposed on the basis of molar conductance, magnetic moment, group theoretical calculations, ligand field parameters, infrared and electronic spectral studies. The proposed structures have also been supported by quantitative values of softness „\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm E}_{\rm n}^{_ + ^ +},{\rm E}_{\rm m}^{_{\rm +}^{\rm +}} $\end{document}“,. Total softness of M and M′ and their difference \documentclass{article}\pagestyle{empty}\begin{document}$ \Delta {\rm TE}_{\rm n}^{_ + ^ +} \left({{\rm M} - {\rm M}'} \right) $\end{document} have also been derived by the following equations and related to the structure of the complexes. \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm TE}_{\rm n}^{_ + ^ +} \left({\rm M} \right) = {\rm E}_{\rm n}^{_ + ^ +} \left({\rm M} \right) + \sum {\rm E}_{\rm m}^{_ + ^ +} \left({\rm L} \right) + \sum {\rm E}_{\rm m}^{_ + ^ +} \left({{\rm NCS}} \right) $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm TE}_{\rm n}^{_ + ^ +} \left({{\rm M}}^\prime \right) = {\rm E}_{\rm n}^{_ + ^ +} \left({{\rm M}}^\prime \right) + \sum {\rm E}_{\rm m}^{_ + ^ +} \left({\rm L} \right) + \sum {\rm E}_{\rm m}^{_ + ^ +} \left({{\rm SCN}} \right) $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ \Delta {\rm TE}_{\rm n}^{_ + ^ +} \left({{\rm M} - {\rm M}^\prime} \right) = \,|\,{\rm TE}_{\rm n}^{_ + ^ +} \left({\rm M} \right) - {\rm TE}_{\rm n}^{_ + ^ +} \left({{\rm M}}^\prime \right)$$\end{document}.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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