Branched supramolecular polymers formed by bifunctional cyclodextrin derivatives

Branched supramolecular polymers have been prepared from the mixture of 3-cinnamarnide-alpha-CD (1) and 3-N-alpha-cinnamamidehexancarbonyl-N-epsilon-cinnamamide-lysinamide-alpha-CD (3) and from the mixture of 3-cinnamamidehexanamide-alpha-CD (2) and 3. Compounds 1 and 2 formed a linear supramolecular polymer, whereas compound 3 having two guest moieties formed a hyperbranched supramolecular polymer. Physical properties of these supramolecular polymers were Studied by viscosity measurement:; in aqueous solutions. When compound 1 was added to the solution of compound 2, the eta(sp)/C value of the mixture of 2 and 3 was found to be much higher than that of compound 2. These results indicate that compound 3 functions as a branching moiety to increase the viscosity. supramolecular polymers consisting of compound 2 or 3 did not show the viscosity increase, whereas the mixture of 2 and 3 gave highly viscous solutions and formed fibers from the concentrated aqueous solutions. It is caused by the branching of linear supramolecular polymers with compound 3 and hydrophobic and/or hydrogen bonding interactions between supramolecular polymers. (C) 2008 Elsevier Ltd. All rights reserved.