Substituent effect and enthalpy-entropy compensation on the inclusion of?-cyclodextrin with 1-substituted naphthalenes

The inclusion complexation ofβ-CD with 1-substituted naphthalenes has been investigated by fluorescence spectroscopy. It was observed that the association constants were influenced by the molar refraction (R m), hydrophobic constant (π x ), and Hammett constant (σ x ) of substituents in the guest compounds. The thermodynamic parameters ΔG0, ΔH 0, and ΔS 0 determined by measuring the temperature-dependentK a values shows that inclusion complex formation is enthalpy driven. The results are discussed in terms of enthalpy-entropy compensation.