HIGH-RESOLUTION H-1-NMR STUDY ON SELF-COMPLEXATION PHENOMENA IN CYCLODEXTRIN DIMERS

The unusual conformational behaviour of a series of new cyclodextrin ( CD) dimers is studied by dedicated H-1-NMR techniques. In water some C D-dimers form stable self-inclusion complexes, for which the aliphatic linker is partially included in one of the two CD cavities. This phen omenon affects the conformation of the substituted sugar ring of one C D moiety. In the case of the alpha-beta heterodimer, the linker appear s to be preferentially in the cavity of beta-CD, in contrast to what i s known for intermolecular complexes where at ambient temperature a pr eference for alpha-CD is observed. (C) 1998 Elsevier Science Ltd. All rights reserved.