Homochiral Helical Poly(thiophene)s Accessed via Living Catalyst-Transfer Polymerization

Abstract

Synthetic helical polymers form compact, ordered, and inherently chiral structures, enabling their uses in biomimetic applications as well as catalysis. A challenge in using synthetic helical polymers, however, is their tendency to be sensitive to pH and the presence of nucleophiles, Lewis-acids, or metal ions. We report a strategy to overcome these shortcomings by adapting catalyst-transfer polymerization, a living chain-growth polymerization typically used to access linear conjugated polymers, for the synthesis of helical poly(thiophene)s. We demonstrate that the helical poly(thiophene)s can be synthesized with a single helicity, incorporated into block copolymers, and functionalized at the chain-ends, enabling further conjugation and functionalization. The helical poly(thiophene)s are stable to a variety of conditions, providing benefits over other helical polymers which contain sensitive imine or carbonyl-based functional groups. We anticipate that the ability to access homochiral, heterotelechelic helical conjugated polymers and copolymers will enable new uses of these materials in optoelectronics as well as in applications for mimicking biomacromolecules and other polymers with precisely defined sequences.