A CALORIMETRIC STUDY OF CHOLESTEROL DISSOLVED IN AN ALCOHOL THE SOLUTE SOLVENT INTERACTION

The molar enthalpies of solution ΔsolH∞m at infinite dilution of cholesterol in each of seven alkan-1-ols (C1 to C7) as well as in propan-2-ol and benzyl alcohol have been determined by calorimetry. Decrease of ΔsolH∞m in the alkan-1-ols from methanol to heptan-1-ol has been attributed primarily to the changes in the structure of the liquid alkanols. The association enthalpies in (cholesterol + butan-1-ol), -25.5 kJ·mol-1, and (cholesterol + heptan-1-ol), -25.9 kJ·mol-1, were determined by the Arnett "pure base" method. It is suggested that the hydroxyl group of cholesterol associates with the alcohol molecules typically for pure alcohols, acting both as proton-donor and proton-acceptor. © 1993 Academic Press. All rights reserved.