T. Aoki et al., CHIRAL HELICAL CONFORMATION OF THE POLYPHENYLACETYLENE HAVING OPTICALLY-ACTIVE BULKY SUBSTITUENT, Chemistry Letters, (12), 1993, pp. 2009-2012
Poly[p-{L-(-)-menthoxycarbonyl}phenylacetylene]s prepared by [Rh(norbo
rnadiene)Cl]2 as a polymerization catalyst exhibited a much higher [al
pha]D20 (= - 605 ) than that(= - 68.8 ) of the monomer and a very high
molar ellipticity(more than 10(4)) at the pi-pi region in the CD spe
ctrum: 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.