Thermodynamic and NMR Study of the Interactions of Cyclodextrins with Cyclohexane Derivatives

Equilibrium constants and standard molar enthalpies of reaction have been determined by titration calorimetry for a series of cyclohexane derivatives (cis-1,2-cyclohexanediol, cis,cis-1,3,5-cyclohexanetriol, trans-1,2-cyclohexanediol, cyclohexanol, cyclohexanone, 2-methylcyclohexanone, 2,5-piperazinedione, and δ-valerolactam) with α-cyclodextrin and β-cyclodextrin. For the reactions involving cyclohexanol, standard molar heat-capacity changes were also determined from calorimetric measurements performed at several temperatures. The equilibrium constants for the reactions of these substances with β-cyclodextrin are in all cases larger than those for the corresponding reactions with α-cyclodextrin