A facile one-pot synthesis of novel amphiphilic perfluoroalkyl ester functionalized γ-cyclodextrin and complex formation with anionic surfactants

gamma-Cyclodextrin (gamma-CyD) was hydrophobically modified by selective functionalization at the C-6 position (primary face) with fluoroalkyl ester groups. This new amphiphilic gamma-CyD was prepared in a facile one-pot synthesis by direct esterification of gamma-CyD with perfluorobutanoic acid on the narrow rim of macrocylic molecule. The selective per-substituted product, octakis (6-O-perfluorobutanoyl)-gamma-cyclodextrin (gamma-CyD-F), was confirmed by H-1 NMR, C-13 NMR and F-19 NMR spectroscopic methods. The complexing ability of the gamma-CyD-F was investigated with different types of anionic surfactant having single or double hydrophobic tail groups. Predominant complex formation was observed in all cases with an equimolar mixture of surfactant and gamma-CyD-F in methanol irrespective of the type of the surfactant. (c) 2006 Elsevier B.V. All rights reserved.