Journal ArticleDOI
Electron transfer reactions between transition metal complexes in micellar solutions
H. Bruhn,J. Holzwarth +1 more
- Vol. 82, Iss: 9, pp 1006-1011
TLDR
In this paper, the influence of anionic micelles (SDS) on the kinetics of diffusion controlled outer sphere electron transfer reactions between transition metal complexes has been investigated, and it was shown that SDS interaction with the reactants can cause ion association (e.g. Os(dipy)) as well as through hydrophobic forces.Abstract:
We report a systematic investigation of the influence of anionic micelles (SDS) on the kinetics of diffusion controlled outer sphere electron transfer reactions between transition metal complexes. — The micelles interact with the reactants through electrostatic repulsion (e. g. IrCl62) or attraction which can cause ion association (e. g. Os(dipy)) as well as through hydrophobic forces (e. g. Fe(phen)2(CN)20). The rate constants kET of these reactions range in the order of 1010 M−1 s−1 in aqueous solution and are decreased by more than four orders of magnitude if these forces superimpose. — By variation of the SDS concentrations and the ionic strengths electrostatic influences were largely eliminated. It was thus possible to establish a hydrophobic barrier in electron transfer reactions between complexes which are solubilized in the hydrophobic core of the micelles and substitution inert complexes in the bulk solution.
Wir berichten uber eine systematische Untersuchung des Einflusses von anionischen Mizellen (NaDS) auf die Kinetik schneller, in wasriger Losung meist diffusionskontrollierter outer-sphere Elektronenubertragungsreaktionen zwischen ubergangsmetallkomplexen. — Die Mizellen wechselwirken mit den Reaktanden durch elektrostatische Abstosung (z. B. IrCl62−) oder Anziehung, die zur Bildung von Ionenassoziaten (z. B. Os(dipy)) fuhren kann, sowie durch hydrophobe Krafte (z. B. Fe(phen)2(CN)20). Die Geschwindigkeitskonstanten. kET, dieser Reaktionen von etwa 1010 M−1 s−1 in H2O werden beim Zusammenwirken dieser Krafte bis zu vier Zehnerpotenzen erniedrigt. — Durch Variation von NaDS-Konzentration und Ionenstarke konnten elektrostatische Einflusse weitgehend ausgeschlossen werden. und eine hydrophobe Barriere bei der Elektronenubertragung zwischen den in Mizellen gelosten Komplexen und den Reaktionspartnern in der Losung nachgewiesen werden.read more
Citations
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Book ChapterDOI
Homoleptic Complexes of 2,2′-Bipyridine
TL;DR: The homoleptic 2,2'-bipyridine (bpy) ligand is a strong field ligand that forms relatively stable complexes, with the inherent M-N bond strength enhanced by the chelate effect as mentioned in this paper.
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Dynamics of micro- and macrophase separation of amphiphilic block-copolymers in aqueous solution
Matthias J. Kositza,Cornelia Bohne,Cornelia Bohne,Paschalis Alexandridis,and T. Alan Hatton,Josef F. Holzwarth +5 more
TL;DR: In this article, the dynamics of purified poly(ethylene oxide)-block-poly(propylene oxide), block-poly (ethylene dioxide) (PEO−PPO−PEO) block-copolymer micellization and phase separation in aqueous solutions were studied using the iodine laser temperature jump and stopped flow techniques.
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Binding of Sodium Dodecyl Sulfate to Some Polyethyleneimines and Their Ethoxylated Derivatives at Different pH Values. Electromotive Force and Microcalorimetry Studies
TL;DR: In this article, the SDS concentration at the onset of binding decreases with decreasing pH, presumably as a consequence of the protonation of the N atoms in the polymer to form a polycation.
Journal ArticleDOI
Use of the pseudophase model in the interpretation of reactivity under restricted geometry conditions. An application to the study of the [Ru(NH(3))(5)pz](2+) + S(2)O(8)(2-) electron-transfer reaction in different microheterogeneous systems.
Pilar López-Cornejo,Pilar Pérez,Francisco Javier Herrera García,Reyes de la Vega,Francisco Sánchez +4 more
TL;DR: The pseudophase model is a powerful tool for the interpretation of kinetic data in the reaction media considered in this work, provided that the specificity of these media were incorporated into the model.
Book ChapterDOI
Octacyano and Oxo- and Nitridotetracyano Complexes of Second and Third Series Early Transition Metals
TL;DR: In this article, a summary on the chemistry of octacyano complexes and oxo-and nitridocyano complexes of molybdenum, tungsten, niobium, tantalum, technetium, and rhenium is presented.
References
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Journal ArticleDOI
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Journal ArticleDOI
Reaction Rates in Ionic Solutions
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Journal ArticleDOI
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E. A. G. Aniansson,S. N. Wall,Mats Almgren,Heinz Hoffmann,I. Kielmann,W. Ulbricht,Raoul Zana,J Lang,C. Tondre +8 more
Journal ArticleDOI
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Journal ArticleDOI
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TL;DR: Ru(bpy)/sub 3//sup 2 +/ is shown to form a water-insoluble salt with dodecyl sulfate ions (DS) which is solubilized by SDS micelles as mentioned in this paper.
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