Poly(ethynylene-2,5-thiophenediylethynylenes). Processable, Reactive Polymers that Thermally Cross-Link

摘要

A polymer cross-linking reaction that proceeds without the evolution of volatiles is especially useful, providing a means of processing void-free parts and devices. If the reaction also is one that maintains Pi conjugation in the product, the system can be designed to generate a material possessing unique properties. To accomplish this, we have synthesized a series of 2,5-diethynylthiophenes and effected their polymerizations to poly (ethynylene-2,5-thiophenediylethynylenes) utilizing the oxidative coupling procedures introduced by Hay for the polymerization of M- and p-diethynylbenzenes. The parent monomer, 2,5-diethynylthiophene and 2,5-diethynyl-3-methylthiophene were obtained by the palladium catalyzed coupling of (trimethylsilyl) acetylene with 2,5-dibromo-thiophene and 2,5-dibromo-3-methylthiophene followed by deprotection. The 3-butyl and 3-hexyl monomers were obtained by the nickel-catalyzed cross-coupling reaction between 3-bromothiophene and butyl-or hexyl magnesium bromide, followed by bromination ethynylation, and deprotection. Keywords: Thienylene, Conducting polymers, Diethynylthiophene, Cross-link, Solid state nmr, Reprints. (aw)