Synthesis of poly(arylene ether)s containing hole-transport moieties from an isocyanate masked bisphenol

The design and synthesis of novel charge (hole- or electron-) transport mat erials have been the focus of much research in recent years because of thei r wide variety of applications. In this study, three high molecular weight poly(arylene ether)s, 6a-c, containing naphthyl-substituted benzidine moiet ies have been synthesized from carbamates derived from bisphenols. After ma sking with n-propyl isocyanate, the carbamate is stable, can be readily pur ified by recrystallization from toluene, and can be polymerized directly wi th difluoro compounds under mild conditions. The resulting polymers possess high glass-transition temperatures, excellent thermal stability, and good film-forming properties. In comparison, the poly(arylene ether)s 6a'-c', sy nthesized from unprotected bisphenol, have lower molecular weights and wide r polydispersity and contain some brown impurities. Preliminary experiments show that both 6a and 6a' can function well as hole-transport materials in light-emitting diodes. (C) 2000 John Wiley & Sons, Inc.