Study of the Controlled Chain-Growth Polymerization of Poly(3,6-phenanthrene)

This manuscript investigates the possibilities to obtain helical conjugated polymers following a controlled chain-growth polymerization mechanism with external initiation. Attempts to prepare poly(3,6-(9,10-di(octyloxy))phenanthrene)s with the existing chain-growth mechanisms using existing Kumada or Negishi couplings were unsuccessful because of the difficulty to quantitatively prepare the Grignard metathesis reagent starting from the envisaged precursor, namely 3,6-dibromo-(9,10-di(octyloxy))phenanthrene. On the other hand, a Suzuki-Miyaura coupling polymerization using Pd((PBu3)-Bu-t) as the catalyst clearly allows the polymerization to proceed. The reaction conditions were optimized and an in-depth study with gel permeation chromatography and matrix-assisted laser desorption ionization time-of-flight (MALDI-ToF) of the underlying mechanisms was performed. Nevertheless, a prolonged chain-growth mechanism was not achieved for the targeted polymers. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 5067-5074