Controlled Synthesis, Chiral Assembly, and Circularly Polarized Luminescence of Poly(phenyl isocyanide)-block-Polyfluorene Copolymers.

In this work, π-conjugated block copolymers consisting of poly(phenyl isocyanide) (PPI) and polyfluorene (PF) segments were facilely prepared by one-pot sequential polymerization of phenyl isocyanide (monomer 1) and 7-bromo-9,9-dioctylfluorene-2-boronic acid pinacol ester (monomer 2). The Pd(II)-terminated PPI was first prepared via polymerizing monomer 1 catalyzed with phenyl alkyne-Pd(II) complex and then utilized to initiate the controlled Suzuki cross-coupling polymerization of monomer 2, yielding various PPI-b-PF copolymers possessing controlled molar mass and narrow dispersity. Owing to the helical conformation of PPI segment and π-conjugated structure of PF segment, PPI-b-PF copolymers presented distinctive optical property and fascinating chiral self-assembly behavior. During the self-assembly process, chirality transfer from helical PPI block to the supramolecular aggregates of helical nanofibers occurred to afford optically active helical nanofibers with high optical activity. Furthermore, the self-assembled helical nanofibers exhibited excellent circularly polarized luminescence performance. This article is protected by copyright. All rights reserved.