Asymmetric anionic homopolymerizations of N-substituted maleimides bearing an azo group (RMI: R=4-(phenylazo)phenyl (PAPMI), 4-(phenylazo)-1-naphthyl (PANMI)) were performed with n-BuLi or Et2Zn—chiral ligand ((1-ethylpropylidene) bis (4-benzyl-2-oxazoline) (Bnbox) or (−)-sparteine (Sp)) complexes to obtain optically active polymers. Trans–cis photoisomerizations of poly(PAPMI) and poly(PANMI) caused by ultraviolet (UV) irradiation were observed from UV spectra. The Cotton effects for trans isomers of poly(PAPMI) and poly(PANMI) were relatively small, but those for cis isomers of poly(PAPMI) and poly(PANMI) clearly exhibited a split circular dichroism curve.
- Tsutomu Oishi
- Motohisa Azechi
- Kenjiro Onimura
