Thermodynamic properties of chiral fenchones in some solutions at T = 298.15 K

Excess enthalpies for binary mixtures (S-fenchone + ethanol/benzene/cyclohexane/carbon tetrachloride) were measured over the whole concentration at T = 298.15 K. The experimental results were compared with the values obtained from the UNIFAC, COSMO-RS and regular solution theory. Excess enthalpies of binary mixtures of R-fenchone and S-fenchone in ethanol, benzene, and cyclohexane solution at different specified mole fractions of fenchone have been measured under the same conditions. With the decreasing of the specified mole fraction of fenchone in different solutions, the excess enthalpies of mixing of chiral orientated solutions increased and became close to zero. Results were compared with those of chiral limonene in ethanol solution. Pair interaction energies were also investigated.

Research highlights
► Polar chiral compounds of S-fenchone and R-fenchone with solvents have been measured even enthalpy changes were very small.
► Excess enthalpies for binary mixtures (S-fenchone + ethanol / benzene / cyclohexane / carbon tetrachloride) were measured over the whole concentration at 298.15 K.
► The experimental results were compared with theoretical values obtained from the UNIFAC, COSMO-RS and regular solution.
► Excess enthalpies of binary mixtures of (R + S)-fenchone and (R + S)-fenchone in ethanol, benzene and cyclohexane solution at different specified molar fractions of fenchone have been measured even under the same conditions.
► The excess enthalpies of mixing of chiral orientated solutions increased and became close to zero. Results were compared with those of non-polar chiral limonene in ethanol solution. Pair interaction energies by ab initio quantum chemical calculation were also investigated.