INDUCTION OF A SINGLE-HANDED HELICAL CONFORMATION THROUGH RADICAL POLYMERIZATION OF OPTICALLY-ACTIVE PHENYL-2-PYRIDYL-O-TOLYLMETHYL METHACRYLATE

Optically active phenyl-2-pyridyl-o-tolylmethyl methacrylate (PPyoTMA) having Various enantiomeric excesses was polymerized with diisopropyl peroxydicarbonate in toluene at 40 degrees C. Isotactic polymers were obtained. The polymers showed large optical rotations which are opposite in sign to the rotation of the starting monomer and the optical activity was higher than expected from the enantiomeric purity of the monomeric units in the polymer, indicating that a right- or left-handed helix was formed in excess from the steric effect of the chiral side group. Copolymerization of PPyoTMA with triphenylmethyl methacrylate (TrMA) also gave optically active, isotactic polymers; the phenyl-2-pyridyl-o-tolylmethyl group is also effective in inducing an excess of a single-handed helix consisting of TrMA monomeric sequences. Copolymerization with MMA gave atactic polymers showing much smaller optical activity than that of the copolymers with TrMA.