Search

Asymmetric anionic homopolymerizations of (S)-(–)-N-maleoyl-L-leucine-aza-15-crown-5 ((S)-A15C5LMI) and (S)-(–)-N-maleoyl-L-phenylalanine-aza-15-crown-5 ((S)-A15C5PAMI) were carried out with chiral anionic initiator consisting of organometal and chiral ligand to obtain optically active polymers. Chiroptical properties and structures of the polymers obtained were analyzed by circular dichroism, ultraviolet, nuclear magnetic resonance and gel permeation chromatography measurements. The additional effects of (R)-cyclohexylethylamine (to the obtained poly((S)-A15C5LMI) were investigated.

Asymmetric anionic homopolymerizations of N-4′-benzo 15-crown-5 maleimide (B15C5MI) were carried out with a chiral anionic initiator consisting of organometal and chiral ligand to obtain optically active polymers. Chiroptical properties and structures of the polymers obtained were analyzed by CD, UV, NMR and gel permeation chromatography measurements. The additional effects of (R)-cyclohexylethylamine ((R)-Cyc) to the obtained poly(B15C5MI) were investigated.

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.

Chiral itaconimides bearing amino-acid esters at side chain (MRII), such as phenylglycine-, phenylalanine- and leucine-methyl ester, were polymerized with organometal-chiral ligand complexes to obtain optically active polymers. The effects of the polymerization conditions on the optical activity and structure of poly(MRII)s were investigated with gel permeation chromatography, circular dichroism, specific rotation and ¹³C nuclear magnetic resonance measurements.