Study of the controlled chain-growth polymerization of poly(3,6-phenanthrene)

ABSTRACT 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(PtBu3) 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. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 5067–5074 The possibility of preparing poly(3,6‐(9,10‐di(octyloxy))phenanthrene)s in a chain‐growth fashion is investigated. Different polymerization protocols were tested and Pd(PtBu3) was found to perform the best. A GPC and MALDI‐ToF study revealed transfer reactions and the formation of macrocyclic rings.