scispace - formally typeset
Search or ask a question
Topic

Aquation

About: Aquation is a research topic. Over the lifetime, 1443 publications have been published within this topic receiving 17507 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: The aquation of tris-(1,10-phenanthroline) iron(II) in acid solution is a reaction for which reliable kinetic data are available and it has an easily measured rate at accessible temperatures.
Abstract: The aquation of tris-(1,10-phenanthroline) iron(II) in acid solution is a reaction for which reliable kinetic data are available and it has an easily measured rate at accessible temperatures

4 citations

Journal ArticleDOI
TL;DR: In this article, a study of the kinetics of hydrolysis for several nitroamminecobalt(III) complexes in strongly alkaline solutions at a constant ionic strength is reported.

4 citations

Journal ArticleDOI
TL;DR: In this paper, the formation of complexes between hydroxypropyl-β-cyclodextrin and 1-alkanols was studied at 298 K in water and in concentrated aqueous solutions of ethanol with the aim of understanding the effects of the solvent medium on the association process.
Abstract: The formation of complexes between hydroxypropyl-β-cyclodextrin or methyl-β-cyclodextrin and 1-alkanols or cycloalkanols has been studied calorimetrically at 298 K in water and in concentrated aqueous solutions of ethanol with the aim of understanding the effects of the solvent medium on the association process. When a complex is formed, calorimetry enables the calculation of both the enthalpy and the association constant, from which the free energy and the entropy of the process can be obtained. The forces involved in the association process are discussed in the light of the signs and values of the thermodynamic parameters obtained. The most important conclusions from this study are: (i) for linear alkanols, hydrophobic interactions are largely the forces acting in the complexation. That is detected by the small enthalpies and by the high and always positive entropies. For cycloalkanols, entropies are positive or negative—an indication that other forces act in the complexation. (ii) In concentrated aqueous solutions of cosolvent, complexation is characterized by enthalpy and entropy changes which depend on the extent of alteration induced by the cosolvent on the structure of water and on the hydration shells of the interacting substances. (iii) A linear correlation exists between enthalpy and entropy of complexation, thus indicating that inclusion is a process dominated by aquation phenomena and ascribed to the modifications experienced by the solvent in the hydration shells of the interacting substances.

4 citations

Journal ArticleDOI
TL;DR: In this paper, the kinetics of the apparent isotopic exchange reaction RuCl63−36Cl−⇆ RuCl536Cl3−+ Cl− have been studied and rate parameters obtained.
Abstract: The kinetics of the apparent isotopic exchange reaction RuCl63–+36Cl–⇆ RuCl536Cl3–+ Cl– have been studied and rate parameters obtained. Increase of the total hydrochloric acid concentration from 6·0 to 11·75 M causes a decrease in the rate of exchange which, in this acid concentration range, is considerably less then the known rate of aquation of RuCl63– in more dilute acid. The activation enthalpy of the exchange in both 6·0 and 11·3M-hydrochloric acid is ca. 25 kcal. mole–1, which indicates that the overall exchange of chloride ions is controlled by the aquation of RuCl63–. The low exchange rates are correlated with the considerable reduction in water activity at high acid concentrations, and this is taken as evidence for the operation of a genuine SN2 type mechanism in the acid hydrolysis of RuCl63–. The effect of producing small amounts of lower oxidation states of ruthenium in RuCl63––36Cl– exchange solutions was investigated. The results indicated that, whereas ruthenium(II) does not cause noticeable catalysis, ruthenium(I) may be extremely active. Irradiations with 2537 and 3660 A light showed that the RuCl63––36Cl– exchange system is not strongly photosensitized by these wavelengths. The small acceleration observed with 3660 A light may arise from photoaquation of RuCl63–.Isotopic chloride-ion exchange experiments were carried out on 0·025M-ruthenium(II) and mononuclear ruthenium(IV) solutions in ca. 11M-hydrochloric acid at 25°. Infinite-time activity distributions indicated that the principal chlororuthenium species undergoing exchange in these solutions were RuCl42–, for ruthenium(II), and a RuCl62––RuOHCl52– equilibrium mixture, for ruthenium(IV). The rates of exchange revealed that the order of ligand lability in the higher (anionic) chloro-complexes of ruthenium is Ru(II) > Ru(III) > Ru(IV). The most important factors which contribute to (i) the variation in rates of solvolytic aquation of Group VIII transition-metal hexachloro-complexes, (ii) the occurrence of depressed rates of aquation at high acid concentrations, and (iii) direct chloride–chloride substitution paths in metal chloro-complexes, are also discussed.

4 citations

Network Information
Related Topics (5)
Ligand
67.7K papers, 1.3M citations
88% related
Ruthenium
40.1K papers, 996.5K citations
88% related
Reactivity (chemistry)
43.8K papers, 833.5K citations
83% related
Intramolecular force
41.6K papers, 772.2K citations
83% related
Crystal structure
100.9K papers, 1.5M citations
82% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20232
20226
202111
202010
201914
20187