Corresponding states, theory ionic liquids

The rigorous theories of fused salts have not yet been developed to a point where they provide a basis for the prediction and correlation of thermodynamic information. For this purpose the most successful theoretical approach has been based on the methods of corresponding states theory. For ionic liquids this approach was developed by Reiss and co-workers.5>6... 

The first method comprises theories based on a statistical description of ionic liquids in a very rigorous way using radial distribution functions obtained from X-ray diffraction. These are theories based on the principle of corresponding states. 

The perturbation theories [2, 3] go a step beyond corresponding states the properties (e.g., Ac) of some substance with potential U are related to those for a simpler reference substance with potential Uq by a perturbation expansion (Ac = Aq + A + Aj + ). The properties of the simple reference fluid can be obtained from experimental data (or from simulation data for model fluids such as hard spheres) or corresponding states correlations, while the perturbation corrections are calculated from the statistical mechanical expressions, which involve only reference fluid properties and the perturbing potential. Cluster expansions involve a series in molecular clusters and are closely related to the perturbation theories they have proved particularly useful for moderately dense gases, dilute solutions, hydrogen-bonded liquids, and ionic solutions. 

Ellegaard, M. D., J. Abildskov, and J. P. O Connell. 2011. Solubilities of gases in ionic liquids using a corresponding-states approach to Kirkwood-Buff solution theory. Fluid Phase Equilibria. 302, 93. 

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