Solubility predictions for crystalline polycyclic aromatic hydrocarbons (PAHs) dissolved in organic solvents based upon the Abraham general solvation model

The Abraham general solvation model is used to predict the saturation solubility of crystalline non-electrolyte solutes in organic solvents. The derived equations take the form oflogCSCW=c+rR2+sπ2H+a∑α2H+b∑β2H+vVxlogCSCG=c+rR2+sπ2H+a∑α2H+b∑β2H+l log L16where CS and CW refer to the solute solubility in the organic solvent and water, respectively, CG is a gas phase concentration, R2 the solute’s excess molar refraction, Vx the McGowan volume of the solute, ∑α2H and ∑β2H are the measures of the solute’s hydrogen-bond acidity and hydrogen-bond basicity, π2H denotes the solute’s dipolarity/polarizability descriptor, and L16 is the solute’s gas phase dimensionless Ostwald partition coefficient into hexadecane at 298 K. The remaining symbols in the above expressions are known coefficients, which have been determined previously for a large number of gas/solvent and water/solvent systems. Computations show that the Abraham general solvation model predicts the observed solubility behavior of pyrene, acenaphthene and fluoranthene to within an average absolute deviation of about +45%.