Chiral Helical Conformation of the Polyphenylacetylene Having Optically-Active Bulky Substituent

Poly[p-{L-(−)-menthoxycarbonyl}phenylacetylene]s prepared by [Rh(norbornadiene)Cl]2 as a polymerization catalyst exhibited a much higher [α]D20 (= −605) than that(= −68.8) of the monomer and a very high molar ellipticity(more than 104) at the π–π* region in the CD spectrum: A chiral helical conformation of the main chain in solution is suggested. The solid membrane of this polymer showed enantioselective permeability (54%ee) for DL-tryptophan.