Synthesis of Triphenylamine-Based Hyper-Branched Polymers via Cobalt-Catalyzed [2 + 2 + 2] Cycloaddition Polymerization of Alkynes and Their Conductive Properties

Hyperbranched polymers bearing triphenylamine (TPA) moieties in the polymer backbone are synthesized via cobalt-catalyzed [2 + 2 + 2] cycloaddition copolymerization of TPA-based diynes and internal monoalkyne monomers. The resulting polymers are soluble in organic solvents, exhibit good thermal stability, and exist in a solid amorphous-like morphology. Hole-only devices made from these polymers exhibit electrical conductivity that is suitable for use as hole injection and transport materials.