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Updated: Jul 17, 2026

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Preparation and properties of rotaxanes formed by dimethyl-beta-cyclodextrin and oligo(thiophene)s with
Kazuya Sakamoto1, Yoshinori Takashima, Hiroyasu Yamaguchi
1Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
Abstract:
Novel cyclodextrin rotaxanes with oligothiophene as an axis molecule have been prepared by the Suzuki coupling reaction of 6-O-(4-iodophenyl)-beta-CD (6-I-Ph-beta-CD) with di(1,3,2-dioxaborolan-2-yl)-oligothiophene (oligothiophene diboric ethylene glycol esters) in aqueous solutions of dimethyl-beta-cyclodextrin (DM-beta-CD). These reactions gave [2]rotaxanes and [3]rotaxanes, which were isolated by reversed phase chromatography. The fluorescence intensities of rotaxanes are higher than those of dumbbell-shaped molecules (without DM-beta-CD) in aqueous solutions. The inclusion ratio and chain length of rotaxanes have been found to relate to the emission properties and emission intensities of oligothiophene. In aqueous solutions, fluorescence quantum yields of rotaxanes are higher than those of dumbbell-shaped molecules. The increase in the fluorescence efficiency of rotaxane is caused by suppression of intermolecular interactions, indicating the effect of insulated oligothiophene with DM-beta-CD. beta-CD at the both ends of rotaxanes functions not only as bulky stoppers but also as the recognition site for guest molecules, as verified by fluorescence quenching experiments.
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