Influence of van der Waals interactions on volumetric properties of cholesterol in solvents of linear structure

The densities of solutions of cholesterol in several primary amines and 1-chloroalkanes have been measured at T=298.15 K. The values of partial molar volumes of cholesterol have been calculated and the effect of solute–solvent and solvent–solvent interactions on the partial molar volume of cholesterol have been discussed. For the solvents studied the increase of alkyl chain length enhances the dispersion solvent–solvent interactions and weakens (per one cholesterol molecule) the contribution of dispersion forces in the solute–solvent interactions. Both effects bring about an increase in the partial molar volume of cholesterol with increasing the alkyl chain length. The relation between interaction volume of cholesterol (s.p.t. calculation) and the alkyl chain length have been also discussed.