Fabrication of supramolecular semiconductor block copolymers by ring-opening metathesis polymerization

ω-Telechelic poly(p-phenylene vinylene) species (PPVs) are prepared by living ring-opening metathesis polymerization of a [2.2]paracyclophane-1,9-diene in the presence of Hoveyda-Grubbs 2nd generation initiator, with terminating agents based on N¹,N³-bis(6-butyramidopyridin-2-yl)-5-hydroxyisophthalamide (Hamilton wedge), cyanuric acid, Pd^II-SCS-pincer, or pyridine moieties installing the supramolecular motifs. The resultant telechelic polymers are self-assembled into supramolecular block copolymers (BCPs) via metal coordination or hydrogen bonding and analyzed by ¹H NMR spectroscopy. The optical properties are examined, whereby individual PPVs exhibit similar properties regardless of the nature of the end group. Upon self-assembly, different behaviors emerge: the hydrogen-bonding BCP behaves similarly to the parent PPVs whereas the metallosupramolecular BCP demonstrates a hypsochromic shift and a more intense emission owing to the suppression of aggregation. These results demonstrate that directional self-assembly can be a facile method to construct BCPs with semiconducting networks, while combating solubility and aggregation.