THERMODYNAMIC STUDIES ON THE HYDROGEN-BONDING OF CHOLESTEROL WITH PROTON-ACCEPTOR SOLVENTS

The standard enthalpies of solution (DELTAH(s)theta) of cholesterol and cholesteryl methyl ether in carbon tetrachloride and some basic solvents were measured by calorimetery. The obtained DELTAH(s)theta values were used for the determination of the enthalpy of the hydrogen-bond complex formation between cholesterol and proton acceptors using the Arnett ''pure base'' method. The enthalpy of hydrogen-bond complex formation ranges from -10.4 (diethylcarbonate) to -24.6 kJ mol-1 (hexamethylphosphortriamide), being a linear function of the solvent basicity.