Polyarylene Networks via Bergman Cyclopolymerization of Bis-ortho-diynyl Arenes†

Bis-ortho-diynylarene (BODA) monomers, prepared from common bisphenols in three high yielding steps, undergo free-radical-mediated thermal polymerization via an initial Bergman cyclo-rearrangement. Polymerization is carried out at 210 °C in solution or neat with large pre-vitrification melt windows (4-5 h) to form branched oligomers containing reactive pendant and terminal aryldiynes. Melt- and solution-processable oligomers with weight-average molecular weight M w = 3000-24 000 g mol -1 can be coated as a thin film or molded using soft lithography techniques. Subsequent curing to 450 °C affords network polymers with no detectable glass transition temperatures below 400°C and thermal stability ranging from 0.5-1.5 % h -1 isothermal weight loss measured at 450°C under nitrogen. Heating to 900-1000 °C gives semiconductive glassy carbon in high yield. BODA monomer synthesis, network characterization and kinetics, processability, thin-film photoluminescence, and thermal properties are described.