Enthalpy and entropy changes on molecular inclusion of pentane derivatives into α-cyclodextrin cavities in aqueous solutions

Abstract

In order to investigate the contribution of the hydrophilic parts of guest molecules of aliphatic compounds to the inclusion reaction, the thermodynamic properties of inclusion compounds of cyclodextrin (α-CD) with eight pentane derivatives into the cavity of α-CD in dilute aqueous solutions were measured by micro-calorimeter at 298.15 K. The thermodynamic properties of the inclusion reactions of pentane derivatives into α-CD were compared to the hydrophobicity and polarizability of guest molecules and discussed. The interaction energies of inclusion compounds of α-CD and pentane derivatives were determined by DFT calculation (B3LYP/6-31G (d,p)) in water and compared with the experimental results.