Modeling Preferential Solvation in Ternary Solvent Systems

Abstract

The theoretical solvent exchange model of Bosch and Rosés for binary solvents was extended to ternary solvent mixtures. The model was applied to ENT values for the mixture methanol/1-propanol/acetonitrile, in terms of 48 new values in a total of 79, measured at 25 degrees C over the whole range of solvent compositions. It was also applied to the mixture methanollethanol/acetone at the same temperature using 93 E(N)T values obtained from literature. Very good fits between experimental and calculated values, substantiated by external validation methods, were achieved for both sets of data. The use of the developed extended model allowed the interpretation of measured solvatochromic shifts in terms of solute-solvent and solvent-solvent interactions in the local environment of the solute's dye for the two ternary systems and the underlying binary mixtures. It also provided the identification of various complex solvent entities and the quantification of their relative concentrations in the probe's cybotactic region, thus leading to new and significant physicochemical insights at a molecular level, regardless of the nonconsideration of the formation of solvent complexes in the bulk. Results clearly showed a different solvent composition in the vicinity of the solute. The further extension of the model to four and five components is also presented.

Surfactant Binary Systems: Ab Initio Calculations, Preferential Solvation, and Investigation of Solvatochromic Parameters

“…37,38 The preferential solvation is an appropriate and easy method for studying solvent−solvent and solute−solvent interactions in which these interactions can explicate many equilibrium and kinetic phenomena. [25][26][27][28]39 This approach is a widely used method for investigating the binary solvent mixtures 40−44 that include experimental studies based on thermodynamic, NMR, IR, and UV−vis measurements. 45−51 Becausee of the simplicity of UV−vis method, it has attracted the most attention of experimental scientist.…”

“…Solutes can preferentially interact with one solvent or mixed solvents in their solvation sphere. This phenomenon is known as preferential solvation. , The preferential solvation is an appropriate and easy method for studying solvent–solvent and solute–solvent interactions in which these interactions can explicate many equilibrium and kinetic phenomena. − , This approach is a widely used method for investigating the binary solvent mixtures − that include experimental studies based on thermodynamic, NMR, IR, and UV–vis measurements. − Becausee of the simplicity of UV–vis method, it has attracted the most attention of experimental scientist. The preferential solvation model was developed by Skwierczynsi et al and later extended by Bosch and Roses. , This model is based on a two-step process, represented by the given formula (eqs and )­ Where I represent the indicator, S 1 and S 2 refer to the pure solvents, and S 12 is utilized for the mixed solvents.…”

SN1 reactions in supercritical carbon dioxide in the presence of alcohols: the role of preferential solvation

“…These trends strongly suggest that ethanol (3b) competes with alkyl halide 1c for solvation. 15 Scheme 4 illustrates the solvation equilibriums 15 for alkyl halide 1 and ethanol (3b) (Steps 1, 2), the exchange of carbon dioxide molecules clustered around 1c and 3b (Step 3), and the integration of further carbon dioxide molecules into the solvation shell of alkyl halide 1 (Step 4) required in the rate determining step (Step 5). Steps 4 and 5 are expected to be strongly sensitive to the cosolutes that compete with the alkyl halide 1c for solvation.…”

Preferential Solvation in Alkan-1-ol/Alkylbenzoate Binary Mixtures by Solvatochromic Probes

“…This model has been successfully applied to a wide range of solvent systems, including alcohol/water binary and ternary mixtures and, more recently, ionic liquids with a number of organic solvents such as N , N -dimethylformamide, dimethylamine, dimethyl sulfoxide, alcohol, dichloromethane, and water, , thus proving it viable to obtain reliable information on solute–solvent and solvent–solvent interactions. The interpretation of physicochemical properties that rely on solute–solvent interactions is expected to face (i) preferential solvation by a solvent constituent, and (ii) influence of solvent–solvent interactions on the solute–solvent interactions .…”