Topic
Aquation
About: Aquation is a research topic. Over the lifetime, 1443 publications have been published within this topic receiving 17507 citations.
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TL;DR: In this paper, the isotopic ligand exchange reactions of cis-dibromotetraammineruthenium(III) were studied in aqueous and methanol-water solutions in order to distinguish them from those in the case of the monobromocomplex and to ascertain the role of water molecule with respect to the reaction mechanism.
Abstract: The isotopic ligand-exchange reactions of cis-dibromotetraammineruthenium(III) were studied in aqueous and methanol-water solutions in order to distinguish them from those in the case of the monobromocomplex and in order to ascertain the role of the water molecule with respect to the reaction mechanism. In an aqueous solution, the reaction proceeds through the rate-determining aquation step with the SN2 mechanism: Ru(NH3)4Br2++H2O→Ru(NH3)4(H2O)Br2++Br−, Ru(NH3)4(H2O)Br2++*Br−→Ru(NH3)4Br*Br++H2O. This result is similar to that for the monobromocomplex. In the methanol solution (H2O∼1.5%), the exchange reaction proceeds through the SN1 mechanism: Ru(NH3)4Br2+→Ru(NH3)4Br2++Br−, Ru(NH3)4Br2++*Br−→Ru(NH3)4Br*Br+. When the concentration of water becomes very low, the number of solvated water molecules decreases; therefore, the coordinated bromide ion may easily be liberated. When the concentration of water is higher than 10%, the rate constant increases with the increase in the water concentration. Since the el...
2 citations
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TL;DR: In this article, the solvent effect on the ion-pair aquation reactions has been investigated spectrophotometrically at different temperatures (30-60 o C) and nonlinear plots of Log (k ip ) ion-pairs rate constants against the reciprocal of the dielectric constant D, Log of water concentration and Grunwald-Winstein Y values were found.
Abstract: The aquation of bromopentaamminecobalt(III) ion in the presence of ion-pairing malonate anion in mixed solvent media of water with tert -butanol (10%-50%) v/v have been investigated spectrophotometrically at different temperatures (30-60 o C). Nonlinear plots of Log (k ip ) ion-pair rate constants against the reciprocal of the dielectric constant D, Log of water concentration and Grunwald-Winstein Y values were found. The thermodynamic and extrathermodynamic analyses of the kinetic data have been discussed in terms of solvent effect on the ion-pair aquation reactions. The obtained isokinetic temperatures of these systems indicate the existence of compensation effect arising from solute-solvent interaction. The extrema found in the change of ∆H ip * and ∆S ip * with the mole fraction of the co-solvent can be attributed to the change of the physical properties of the solvent-water mixture with the solvent structure. Application of a free energy cycle is performed to compare between the stability of the initial and the transition state of the complex. However, small changes in ∆G ip * with the mole fraction of the co-solvent was found, indicating a compensating effects between ∆H ip * and ∆S ip *
2 citations
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TL;DR: The aquation of cis-bromochlorobis(ethylenediamine)chromium(III) cation was studied at 15.3-24.9°C in 0.10 M and 0.010 M HClO4 as mentioned in this paper.
2 citations
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2 citations
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TL;DR: In this paper, the aquation of pentaammine (substituted salicylato) cobalt(III) complexes in the presence of ferric ion was studied spectrophotometrically in the 65°-80° range.
Abstract: The aquation of pentaammine (substituted salicylato) cobalt(III) complexes [(NH3)5CoO2CC6H3(X)OH]2+,X = 5-SO3, 5-Br, 5-NO2, and 3-NO2 in the presence of ferric ion was studied spectrophotometrically in the 65°–80° range. Ferric ion catalyses the aquation of the substratesvia formation of a reactive binuclear species.
2 citations