“…The Rohrschneider/McReynolds system of phase constants [6,15,318,327,328,380,397,[401][402][403], solubility parameters [6], the solvent selectivity triangle of Snyder [336], Hawkes polarity indices [404], dispersion and selectivity indices [331,405], universal indices [406] and various thermodynamic approaches [303,397,404,407] have been the most widely used. Unfortunately, fundamental approaches have not advanced to the point where an exact model can be put forward to describe the principal intermolecular forces between complex molecules.…”