Constructions of Conjugated Macromolecules from Acetylenic Building Blocks: Syntheses and Properties of Hyperbranched Polyarylenes and Polyynes

Hyperbranched polyarylenes and polyynes with high molecular weights (up to 1 x 106) are prepared in high yields (up to 99.9%) by alkyne polycyclotrimerization and polycoupling. All the polymers exhibit low intrinsic viscosities and outstanding thermal stabilities, losing little of their weights when heated to > 400 DGC. The polymers graphitize or ceramize at temperatures > 800 DGC in high yields (up to 86%). Poly(arylphenylene)s emit strong deep-blue to blue-green light with fluorescence quantum yields up to 98%. They strongly attenuate intense laser pulses, with their optical power-limiting performances superior to that of [60]fullerene, a wellknown optical limiter. The polycyclotrimerization of bis(aryl ethynyl ketone)s initiated by secondary amine gives regioregular hyperbranched poly(aroylarylene)s, which can be readily cross-linked by UV irradiation. Cu-catalyzed alkyne polycoupling yields hyperbranched polyynes, whose thin films exhibit high refractive indexes. Their internal and terminal acetylene moieties readily form complexes with metal carbonyls, which can be transformed to soft ferromagnetic ceramics with high magnetic susceptibilities (MS up to -118 emu/g).