Stereospecific Styrene Enchainment at a Titanium Site within a Helical Ligand Framework:Evidence for the Formation of Homochiral Polystyrene

摘要

The phenomenon of cryptochirality renders isotactic poly(alpha-olefin)s such as polypropylene optically inactive,since C_s symmetry can be assumed for high-molecular-weight poly mers formed from prochiral olefins.Only for highly specific sequences of segments within the poly(alpha-olefin)chain can optical activity be measured.