Takakazu Yamamoto, K. Sanechika, A. Yamamoto
May 1, 1983
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0
Influential Citations
177
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Journal
Bulletin of the Chemical Society of Japan
Abstract
Nickel compounds (NiCl2 and NiCl2(2,2′-bipyridine)) catalyze polycondensation of dihalothiophenes (2,5-dihalothiophenes, 2,4-dibromothiophene, and 3-methyl-2,5-dibromothiophene) by dehalogenation with magnesium to give the corresponding poly(thienylene) type polymers (poly(2,5-thienylene), poly(2,4-thienylene), and poly(3-methyl-2,5-thienylene)). Copolymerization of 2,5-dibromothiophene and 2,4-dibromothiophene affords copolymers formulated as (\llap–2,5-C4H2S) \llap–m(\llap–2,4-C4H2S) \llap–n. About 15 wt% of poly(2,5-thienylene) prepared in THF at 66 °C is soluble in CHCl3 at room temperature and the CHCl3-soluble fraction has a molecular weight of 1370. The remaining fraction is considered to have a higher molecular weight as judged from its physical properties. IR and 1H-NMR spectra of the polymers are consistent with the structures described above. The electronic spectra of poly(2,5-thienylene) and poly(3-methyl-2,5-thienylene) show large bathochromic shifts of the π-π* absorption bands from those of...