The binding behavior of cyclodextrins toward a nitroxide spin probe in the presence of different alcohols as studied by EPR

Stability constants, rates of association and dissociation, and thermodynamic and activation parameters for the formation of inclusion complexes between the radical guest, N-benzyl-tert-butyl-[d.sub.9]-nitroxide and [beta]- or 2,6-O-dimethyl-[beta]-cyclodextrin (CDs), are determined by EPR spectroscopy in water in the presence of different alcohols, differing in size and lipophilicity. EPR spectroscopy is considered as a rapid and accurate technique in order to examine the CDs binding behavior toward different nonradical guest.