Analysis of dipolarity/polarisability parameter, π*, for a range of supercritical fluids

Abstract

The dipolarity/polarisability parameter, π*, of Kamlet and Taft can be used to characterise the solvent properties of supercritical fluids and hence its correlation to more readily available parameters is important for predictive purposes. Almost perfect correlations are demonstrated between the π* parameter and the cohesive energy density parameter, δ_H², as a function of solvent type, temperature and pressure. Correlation is also observed between π* and solvent dipole moment at constant reduced density. It is shown that the Gibbs energy of dissociation data can be modelled using δ_H² and π* parameters.