Solvent effects on the kinetics of aquation of ?-chloro(diethylenetriamine) (ethylenediamine)cobalt(III) ion in mixed aqueous solvents

Abstract

Solvent effects on the kinetics of aquation of [Co(dien)(en)Cl] have been investigated within the temperature range (40 -60°C) in acetone-water and ethanol-water media of varying solvent compositions up to 60% by weight of the organic solvent component. The variation of the activation parameters (⌬G # , ⌬ H # , and ⌬S # ) with the mole fraction of the organic solvent component was analyzed and discussed. The isokinetic plots were linear in both solvent systems and revealed the existence of compensation effect due to a strong solute-solvent interactions. The correlation of log k with the ionizing power (Y) was found to be linear in both solvent mixtures. Moreover, the correlation of log k with was linear in case of ethanol-water medium while in case of acetone-water it was nonlinear.

Kinetics and mechanism of aquation of bromopentammine cobalt(III) cation assisted by ion-pairing succinate anion in ethane-2-diol-water mixtures

“…The log A/k versus Eb/log (C/D) gives a good straight line passing through origin with a slope equal to 0.0520, which is in consistent with the theoretical one (0.0522). As shown in Figure 5, the plot was found to be non linear in accordance with the general observations found in the aquation of a large number of other cobalt(III) complexes [19][20][21][22][23][24][25] in water-cosolvent mixtures, which led to a conclusion, that the contribution of the non electrostatic part of solvent effect, overcomes the electrostatic component part. Also log kip was plotted against reciprocal of the dielectric constant D at different temperatures, where the dielectric constant values of different compositions are obtained from Akerlöf data [18].…”

Kinetics of Malachite Green Fading in Water‐ethanol‐1‐propanol Ternary Mixtures

“…Thus, the ordering influence of the hydrophobic molecules will be decreased and the entropy decreases and thermal energy is required for the destructuring of the hydration shells around hydrocarbon molecules. 31 Also, dissolution of 1-propanol in water is exothermic and increases entropy of reaction. Therefore, with increase in 1-propanol concentration DS ¹ and DH ¹ values become less negative and more positive, respectively and with more increase in 1-propanol concentration DS ¹ and DH ¹ values become more negative and less positive, respectively.…”

Kinetics of malachite green fading in water–ethanol–2‐propanol ternary mixtures

“…Data of Tables I–V were analyzed by the SESMORTAC model. In the SESMORTAC model 16, a range of solvent composition in which the equation of logarithm of the reaction rate constant, log k , versus a reciprocal of dielectric constant of the solution, D −1 , is linear 27–34, is called a “zone” and a solvent composition in which a zone finishes and another zone starts, is called “ m echanism c hange point” (or abbreviated as the mc point). Considering a mechanism on the basis of point charge on a dielectric continuum suggests that the plots of log k against D −1 should be linear.…”