PET‐RAFT Polymerization of Star Polymers with Folded ortho‐Phenylene Cores

Abstract

Abstractortho‐Phenylenes are one of the simplest classes of aromatic foldamers, adopting helical geometries because of aromatic stacking interactions. The folding and misfolding of ortho‐phenylenes are slow on the NMR timescale at or below room temperature, allowing detection of folding states using 1H NMR spectroscopy. Herein, an ortho‐phenylene hexamer is coupled with a RAFT chain transfer agent (CTA) on each repeat unit. A variety of acrylic monomers are polymerized onto the CTA‐functionalized ortho‐phenylene using PET‐RAFT to yield functionalized star polymers with ortho‐phenylene cores. The steric bulk of the acrylate monomer units as well as the chain length of each arm of the star polymer is varied. 1H NMR spectroscopy shows that the folding of the ortho‐phenylenes do not vary, providing a robust helical core for star polymer systems.