Thermodynamics of Binding of α:-Cyclodextrin to Straight-Chain Alkyl Derivatives in Aqueous Solution

Apparent standard Gibbs energy, enthalpy, entropy, and heatcapacity data of the interactions of α-cyclodextrin (αCD) to some n-carboxylatesH(CH2)nCOO- (n = 4–6), are determined by isothermal titration microcalorimetryat different temperatures in phosphate buffer, pH 9.0, assuming a 1 : 1 model indilute solution. Modelling of contributions of the thermodynamic properties of the solutionindicates that αCD undergoes conformational change upon binding to homologousseries of n-carboxylates, n-alcohols, α ,ω-alkane dicarboxylates andα ,ω-alkane diols.