Novel soluble and fluorescent poly(arylene ether)s containing p-quaterphenyl, 2,5-bis(4-phenylphenyl)oxadiazole, or 2,5-bis(4-phenylphenyl)triazole groups

Three novel conjugated biphenols 3, 4, and 8 were synthesized by the Pd(OAc )(2)-catalyzed regioselective carbon-carbon coupling reaction of 2,6-di-ter t-butylphenol or 2-phenylphenol with aryl halides. Although poly(arylene et her)s derived from biphenol 3 and arylene difluorides have low solubility i n organic solvents, using 4,4'-(9-fluorenylidene)diphenol or 4,4'-(hexafluo roisopropylidene)diphenol as a comonomer gave soluble poly(arylene ether)s 6a-c. High molecular weight poly(arylene ether)s 7a'-c' were also prepared from biphenol 4. The biscarbamate-masked monomers 5 and 9 improved the poly merization to give higher molecular weight polymers 7a-e and 10a-e in highe r yields. Polymers 7 and 10 possess better film-forming capabilities and ar e still soluble in organic solvents. Polymers 6, 7, and 10 are all thermall y stable with 5% weight loss temperatures higher than 500 degreesC under ni trogen. The polymers show strong blue light emission ranging from 387 to 47 8 nm in solution, depending on the conjugated structure.