Inclusion Compound from a Semifluorinated Alkane and β-Cyclodextrin

Abstract

Inclusion compounds (ICs) were obtained for the first time from a semifluorinated n -alkane (F(CF 2 ) 8 (CH 2 ) 16 H, abbreviated F 8 H 16 ) with β-cyclodextrin (β-CD) in water. Because of the hydrophobic nature of the two constituent blocks, the semifluorinated alkane readily penetrates the hydrophobic CD's cavity, to avoid contact with water, and produces a fine crystalline powder. The crystalline ICs were studied through differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffractometry, and atomic force microscopy, and they were identified as novel systems, with different structure and behavior from the two parent molecules. According to X-ray diffractometry, the host−guest system presents the channel type structure that is typical of polymer−CD inclusion compounds. Atomic force microscopy confirms the presence of tubular structures obtained from dispersion of the F 8 H 16 /β-CD inclusion compound. The formation of such supramolecular assemblies may be useful for the encapsulation of fluorinated hydrophobic materials and for the insertion of specific polymeric chains onto the surface of cyclodextrin-grafted fibers and textiles.