Research Theme

Preparation of Supramolecular Complexes with p-Conjugated Molecules

Preparation of pseudo-Polyrotaxanes Containing Poly(thiophene)s

p-Conjugated polymers have attracted much interest due to their high charge-mobility along individual polymer chains. Recently, p-conjugated polymers have been used in practical applications, including light-emitting diodes, thin-film field effect transistors, photovoltaic cells, and sensors. We have prepared and determined the crystal structure of cyclodextrins inclusion complexes with various thiophenes, and the polymerization of the corresponding inclusion complexes in a selective way to obtain polyrotaxanes.

Utlizing coupling reaction, DM-β-CD poly pseudo rotaxane with polythiophene as axis was obtained.

Takashima, Y.; Sakamoto, K.; Oizumi, Y.; Yamaguchi, H.; Kamitori, S.; Harada, A.
Complex Formation of Cyclodextrins with Various Thiophenes and Their Polymerization in Water: Preparation of pseudo-Polyrotaxanes Containing Poly(thiophene)s
J. Incl. Phenom. Macrocycl. Chem. 2006, 56 (1-2), 45-53.

Preparation and Properties of Rotaxanes Formed by Dimethyl-β-Cyclodextrin and Oligo(thiophene)s with β-Cyclodextrin Stoppers

A series of novel DM-β-CD-oligothiophene based rotaxanes have been prepared by the palladium catalyzed coupling reaction. [2] Rotaxanes and [3] rotaxanes which have various chain lengths and inclusion ratios of DM-β-CD were isolated from the crude products by using preparative reversed phase chromatography. Their photochemical properties have been investigated by UV-vis and fluorescence measurements. The inclusion ratio and the chain length of rotaxanes have been found to relate to the emission properties and the emission intensities of oligothiophene. In aqueous solutions, fluorescence quantum yields of rotaxanes were higher than those of dumbbell-shaped molecules. The increase in the fluorescence efficiency of rotaxane is caused by the suppression of intermolecular interactions, indicating the effect of insulated oligothiophene with DM-β-CD.

Sakamoto, K.; Takashima, Y.; Yamaguchi, H.; Harada, A.
Preparation and Properties of Rotaxanes Formed by Dimethyl-beta-cyclodextrin and Oligo(thiophene)s with beta-Cyclodextrin Stoppers
J. Org. Chem. 2007, 72 (2), 459-465