Polyallene-block-polythiophene-block-polyallene Copolymers: One-Pot Synthesis, Helical Assembly, and Multiresponsiveness

Abstract

A family of coil–rod–coil ABA triblock copolymers containing poly(3-hexylthiophene) (P3HT) and poly(hexadecyloxyallene) (PHA) were facilely synthesized in one-pot via three sequential living polymerizations of hexadecyloxyallene, 2-bromo-3-hexyl-5-chloromagnesiothiophene, and hexadecyloxyallene using the π-allylnickel complex as a single catalyst. Although the different monomers were polymerized under distinct polymerization mechanisms, the one-pot block copolymerization were revealed to proceed in a living/controlled chain-growth manner, affording well-defined PHA-b-P3HT-b-PHA triblock copolymers in high yields with controlled molecular weights and tunable compositions. The isolated triblock copolymers were found to self-assemble into well-defined supramolecular helical polymers with equivalent of right- and left-handedness. The helicity of the assemblies can be facilely tuned through the induction of chiral cholesteryl pendants introduced on the polyallene segments. Moreover, by using this synthetic met...