Effect of Rotaxane Formation on the Photophysical, Morphological, and Adhesion Properties of Poly[2,7-(9,9-dioctylfluorene)-alt-(5,5′-bithiophene)] Main-Chain Polyrotaxanes

In order to investigate the effect of rotaxane formation on the photophysical and morphological properties of p-conjugated materials, a new main chain polyrotaxane was synthesized through Suzuki coupling between the inclusion complex of 5,5'-dibromo-2,2'-bithiophene with randomly methylated beta-cyclodextrin and 9,9-dioctylfluorene-2,7-trimethylene diborate. Due to rotaxane formation, a blue shift in the absorption spectra as well as in the fluorescence spectra was observed, while the fluorescence quantum yields and fluorescence lifetimes remained unchanged. This study demonstrates that rotaxane formation can alter the electronic and morphological properties of the threaded copolymer, which is of great interest for electronic applications.