The nature of 4-aminophthalimide-cyclodextrin inclusion complexes

Abstract

The complexation between 4-aminophthalimide and cyclodextrin has been investigated in aqueous solution using steady-state and time-resolved fluorescence techniques. While 1:1 complex formation with α- or β-cyclodextrin is evident from the presence of the isosbestic point in absorption and analysis of fluorescence spectral data, the binding is rather weak with γ-cyclodextrin and more than one type of complex are indicated. The complexes of α- and β-cyclodextrins have been characterized through the measurement of fluorescence spectra, quantum yields, and lifetimes. On the basis of the available experimental data and the results of AM1 calculation on the probe molecule, possible structures of these complexes are suggested. © 1992 American Chemical Society.