Helicity induction in N-[(4-butyl)triphenylmethyl]methacrylamide sequence via radical copolymerization with chiral monomers

The radical copolymerization of N-[(4-butyl)triphenylmethyl]methacrylamide (BuTrMAM) with optically active monomers, such as N-[(R)-(+)-1-(1-naphthyl)ethyl]methacrylamide, N-[(S)-(-)-1-(I-naphthyl)ethyl]methacrylamide, N-((S)-(+)-1-cyclohexylethyl)methacrylamide, N-((R)-(-)-1-cyclohexylethyl)methacrylamide, N((S)-(-)-1-benzylpyrrolidin-3-yl)methacrylamide, and N-((R)-(+)- 1-benzylpyrrolidin-3-yl)methacrylamide, was carried out. The optical activity of the obtained copolymers significantly depended on the monomer contents. When the chiral monomer content was low in the copolymers, the chiral monomeric units were effective in inducing an excess of the one-handed helix consisting of BuTrMAM monomeric sequences. The helicity induction was most effectively attained using N-[1-(1-naphthyl)ethyl]methacrylamide at low temperature. The chiroptical properties and chiral recognition ability of the obtained copolymers were studied in detail.