Helicity induction on macromolecules

Abstract

Helicity induction on optically inactive polymers bearing functional groups via non-covalent bonding interactions with chiral compounds is described, especially focusing on poly (phenylacetylene) and poly(organophosphazene) derivatives. Stereoregular, optically inactive poly (phenylacetylene) s bearing a carboxy, an amino, a phosphono, or a boronic acid group respond to the chirality of various optically active compounds capable of interacting with the functional groups and the complexes exhibit a characteristic induced circular dichroism in the UV-visible region in organic solvents as well as in water. These polymers form a dynamic, one-handed helical conformation upon complexation with chiral compounds and can be considered as a promising candidate for a novel probe to determine the absolute configuration of various chiral compounds. Moreover, the induced macromolecular helicity can be memorized by replacing the chiral compounds with achiral ones. Poly (organophosphazene) bearing carboxy groups also forms a dynamic, one-handed helical conformation upon complexation with optically active amines. Other examples of helicity induction on optically inactive polymers and oligomers are also briefly described.