Study on helix conformations of poly(phenylacetylenes) with bulky amino acid pendant groups

Polymers bearing bulky amino acid pendants have been prepared to study the effects of bulkiness of substituents on the helical structures of poly(phenylacetylenes) (PPAs). Intense circular dichroism (CD) bands arising from electronic transitions of the PPA backbones are observed in all polymers. This suggests that the main chains are chiral owing to predominant one-handed helix sense.