Aquation

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

Kinetics of aquation of penta-amminechlororuthenium(iii)dichloride and cis-dichlorobis(ethylenediamine)ruthenium(iii)chloride hydrate in mixed water-organic solvents

Abstract: Kinetic data are reported for the spontaneous aquations of [Ru(NH3)5Cl]Cl2 and cis-[Ru(en)2Cl2]Cl in a variety of mixed water–organic solvents. Plots of log kH2O against Grunwald–Winstein Y values are linear with gradients ca. 0.25, suggesting essentially SN1 mechanisms. The Hg2+-catalysed aquation of [Ru(NH3)5Cl]2+ has also been studied in both aqueous solution and in a variety of mixed water–organic solvents. Kinetic data in aqueous solution are consistent with pre-equilibnum formation of a chloro-bridged intermediate, [(NH3)5Ru–Cl–Hg]4+, followed by dissociation to release [HgCl]+ and the rapid pick up of water. Plots of log kHg2+ against Y values for the Hg2+-catalysed aquation in mixed solvents are markedly non-linear. This unusual behaviour is discussed in terms of the pre-equilibrium mechanism.

Metal ion induced aquations—II: The kinetics of the heterogeneous catalysis by silver iodide in the reaction of iodopentaamminecobalt(III) ions with silver ions

Abstract: The kinetics of the silver iodide heterogeneous catalysis of the silver ion induced aquation of iodopentaamminecobalt(III) ion was studied at 44.9°C in the ionic strength range of 4.84–90.1 × 10−3 M, and with different preparation methods and aging times for the silver iodide. The results indicate that the rate of catalysis depends on the concentrations of silver ions and iodo-complex ions, the mole/liter (instead of surface area) of the silver iodide, the age and preparation of the silver iodide, and the ionic strength. With freshly prepared silver iodide, the rate increases sharply and then decreases with increase in silver ion concentration; whereas with aged and homogeneously precipitated silver iodide, the rate simply increases. A proposed mechanism for this catalysis involves two mutual displacement reaction paths and the relative rate of disappearance of two different types of surface sites with aging.

Studies on the Kinetics and Mechanism of Redox Decomposition of

Abstract: Summary In aqueous acid media the title complexes undergo decomposition ultimately forming cobalt(II). Detailed analysis of the kinetic data reveals that the reactions proceed in two consecutive stages, the initial step being the faster one. Evidence has been presented that the initial faster step involves aquation releasing one NO~ ligand and forming an aquodinitro complex, which subsequently undergoes a slower intramolecular redox decomposition into Co 2+. Each step, on the other hand, has been found to consist of two concurrent paths, viz. spontaneous and acid catalysed, respectively. Activation parameters corresponding to all these specific rate constants have been evaluated and a plausible mechanism for the overall reaction has been proposed.