Ionic solvates, basic properties

Theoretical considerations based upon a molecular approach to solvation are not yet very sophisticated. As in the case of ionic solvation, but even more markedly, the connection between properties of liquid mixtures and models on the level of molecular colculations is, despite all the progress made, an essentially unsolved problem. Even very crude approximative approaches utilizing for example the concept of pairwise additivity of intermolecular forces are not yet tractable, simply because extended potential hypersurfaces of dimeric molecular associations are lacking. A complete hypersurface describing the potential of two diatomics has already a dimensionality of six In this light, it is clear that advanced calculations are limited to very basic aspects of intermolecular interactions,... 

A solvent, in addition to permitting the ionic charges to separate and the electrolyte solution to conduct an electrical current, also solvates the discrete ions, by ion-dipole or ion-induced dipole interactions and by more direct interactions, such as hydrogen bonding to anions or electron-pair donation to cations. Lewis acidity and basicity of the solvents affect the latter. The redox properties of the ions at an electrode depend on their being solvated, and the solvation effects electrode potentials or polarographic half-wave potentials. 

Through these well-known examples the effect of three basic features of organized assemblies can be visualized (1) inhomogeneous solvation properties, (2) interfacial potentials, and (3) spatial confinement. Apart from the last, the other aspects can be finely controlled at the polarizable ITIES. As we have seen in Section II, the Galvani potential difference not only affects the dynamics of photoinduced electron transfer, but also the concentration ratio of ionic species. 

Ion-pair extraction is a method for partition of ionic compounds with the aid of counter-ions of opposite charge. Ion-pairs are formed in the organic solvent and their distribution depends on their solvation properties. Initially, the technique was used to extract basic and acidic compounds with counter-ions of different hydro-... 

Where SP is a solvation p>arameter related with the free energy change such as gas-liquid partition coefficient, specific retention volume or adjusted retention time at a given temperature. The capital letters represent the solutes properties and the lower case letters the complementary properties of the ionic liquids. The solute descriptors are the excess molar refraction E, dipolarity/ polarizability S, hydrogen bond acidity basicity, A and B, respectively, and the gas-liquid partition coefficient on n-hexadecane at 298 K, L. The solute... 

---