BRANCHED HOST-GUEST SUPRAMOLECULAR POLYMERS

The obtainment of sophisticated structure by assembling molecules through non-covalent interactions represents a fundamental topic in supramolecular chemistry. In this field, a lot of work has been addressed towards the preparation of supramolecular polymers, which are generated by a directional and reversible connection of monomers. In particular, during the past few years, data on several host-guest linear supramolecular polymers, exploiting the hosting properties of cyclodextrins, have been published. Polymers have been obtained either by mixing unimers carrying complementary units, i.e. host and guest sites, or complementary monomers having two interacting host or guest moieties. Recently, moreover, branched structures have been prepared by mixing tritopic host and ditopic guest derivatives. Although very few papers have been published on this subject, these structures seem to be very interesting either because they are particularly new or because of the applicative importance of molecules with similar structure (dendrimers). In the light of these results, in this work, we reported preparation and characterization of polymers by connection of tritopic host and ditopic guest derivatives, exploiting the highly favorable interaction between the adamantyl group and the beta-cyclodextrin cavity. The structure of the polymers were studied by combining Small Angle X-Ray Scattering and Static and Dynamic Light Scattering measurements. Besides the conventional analysis of the scattering data, the 3D reconstruction of the electronic density distribution was performed from the SAXS spectra. Moreover, the hydrodynamic radii were estimated, from the shape of the electronic density distribution, and compared with the experimental ones.