Journal of the American Chemical Society, Vol.127, No.9, 2984-2989, 2005
Chiral supramolecular polymers formed by host-guest interactions
alpha-Cyclodextrin with a p-t-butoxyaminocinnamoylamino group in the 3-position (3-p-(t)BocCiNHa-alphaCD) has been found to form a supramolecular polymer in an aqueous solution. The degree of polymerization of the supramolecular polymer is higher than 15 at 20 mM, as proved by VPO (vapor pressure osmometry) measurements and turbo ion spray TOF MS measurements. The existence of substitution/ substitution interactions between adjacent monomers of the supramolecular polymer have been confirmed by the observation of positive and negative Cotton bands in circular dichroism spectra. The mechanism for the induction of the chirality was confirmed using model compounds. The substituents were found to exist as a left-handed anti configuration in supramolecular polymers. The supramolecular polymer was found to take a helical structure. The structure of the supramolecular polymer was observed by STM measurements.