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1.
J. L. Oscarson R. M. Izatt P. R. Brown Z. Pawlak S. E. Gillespie J. J. Christensen 《Journal of solution chemistry》1988,17(9):841-863
The aqueous reactions,
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2.
Zusammenfassung Die Verbindung GeY · 2 H2O wird nach einem Verfahren dargestellt, das die Verwendung von flüchtigem GeCl4 vermeidet und direkt von Germaniumsäure-Lösungen ausgeht. Der Komplex, der analysenrein anfällt, wird thermogravimetrisch untersucht. In Wasser gelöst, erweist er sich als einbasige Säure, H[Ge(OH)Y]. Die Dissoziationskonstante der komplexen Säure wird potentiometrisch bestimmt:K
c
=3,99 · 10–3 (pK
c
=2,40). Die Stabilitätskonstanten der komplexen Säure sowie des komplexen Anions werden ermittelt:
=6,27 · 104 (log
=4,80);
=3,34 · 104 (log
=4,52) (25°C; Ionenstärke 0,1m).
The complex compound GeY · 2 H2O is prepared directly from germanic acid solutions, avoiding volatile GeCl4. It has been submitted to thermogravimetric analysis. Dissolved in water, it proves to be a monobasic acid, H[Ge(OH)Y]. The dissoziation constant of the complex acid is determined potentiometrically:K c =3,99 · 10–3 (pK c =2,40). The stability constants of the complex acid as well as of the complex anion are evaluated: =6,27 · 104 (log =4,80); =3,34 · 104 (log =4,52), at 25°C; ionic strength 0,1m. Mit 4 Abbildungen Herrn Prof. Dr.J. W. Breitenbach zum 60. Geburtstag gewidmet. 相似文献 3.
A. M. Koganovskii 《Colloid Journal》2004,66(1):48-51
It is proven that, when passing from a liquid into an adsorption phase on a carbon surface, the maximal number of H-bonds between water molecules decreases from four to three because of the screening of one unpaired electron of the oxygen atom of an adsorbed water molecule by aromatic rings of the carbon surface. An energy gain equal to the energy of one H-bond arises upon water desorption by organic molecules adsorbed from an aqueous solution. The ratio between the number of H-bonds of a group of water molecules, which is displaced into a solution by one organic molecule, in the solution and in the adsorption phase is independent of the number of molecules in this group and is, on the average, equal to 2.038 for all possible structures of H-bonds in both phases. The allowance for this ratio in the isotherm of water desorption into a solution and the introduction of a coefficient, which depends on the relative water content (
) in the adsorption phase, in the form of
into the equation of the desorption isotherm make it possible to determine the balance of the change in the Gibbs energy at the desorption equilibrium and the standard Gibbs energy
= –1.76 kJ/mol of water desorption into a solution from a carbon surface. This value determined by an independent method is
= –1.79 kJ/mol; i.e., both values are close to each other. The RTlnf energy of the additional H-bond, which is formed between water molecules upon passing from the adsorption phase into the solution, is found by the extrapolation of the isotherms of water desorption by molecules of several benzene derivatives. This energy ranges from 9.13 to 9.24 kJ/mol, thus corresponding to the energy of one H-bond, as measured by IR spectroscopy and NMR. 相似文献
4.
The kinetics of substitution of aqua ligands from the hexaaquochromium(III) ion by 2-aminopyridine (2-ampyH+) in aqueous medium has been studied spectrophotometrically in the 40–55° C range. The rate law involving the outer sphere complex formation has been established at pH 2.7 as
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