In this study, we synthesized a novel optically active polymer containing azobenzene in the main chain. We attempted to induce a helical structure in the main chain by introducing a chiral substituent. Introduction of an azobenzene moiety in the polymer backbone allows to control helical direction with light irradiation. Azobenzenes show rapid and reversible isomerization between rod-like trans-isomer and cis-isomer by irradiation of UV or visible light. In the previous studies, conjugated polymers having azobenzene units and various conjugated moieties in the main chain has been synthesized. Molecular design for obtaining polymers having solubility and high molecular weight has been carried out. Introduction of chiral substituents into conjugate polymer can induce main chain helical structure. Therefore, combination of light isomerization function and chirality of conjugated polymer produces light-driven change in chiroptical activity accompanied by structural change of azobenzenes. In this research, we successfully synthesized an optically active polymer containing azobenzene in the main chain. Optical properties of the polymer were evaluated by in-situ UV-vis absorption spectra, in-situ circular dichroism (CD) spectra, and fluorescence spectra. Repeatable photo-isomerization behavior of the polymer by repeating irradiation of UV and Vis light was confirmed. From the CD spectra, photo-isomerization of azobenzene moiety can tune the 3-D structure of the main chain. Polymerization in azobenzene-based liquid crystal solvent is also carried out. In this communication, we report synthesis and "chiral-photo-responsive" function of the azobenzene based polymer.

Synthesis of photo-responsive optically active conjugated polymers and photo-reaction field

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.