Poly[3-(3', 5'-di-tert-butyl-4'-acetoxyphenyl)thiophene] (la) was regioselectively synthesized via simple oxidative polymerization of 3-(3', 5'-di-ferf-butyl-4'-acetoxyphenyl)thiophene (2a) with ferric chloride. Head-to-tail content of la with a molecular weight of > 104 reached 96% by modulating both the polymerization conditions and the purification procedure of the polymer. Visible absorption and fluorescence maxima were bathochromically shifted for both la and poly[3-(3', 5'-di-tert-butyl-4'hydroxyphenyl)thiophene] (Ib), which suggests an extended, -r-conjugation, i.e., a regioregular structure. Redox of the phenolate and of the thiophene residue of Ib was observed reversibly and independently under alkaline conditions. The polyphenoxyl 1 derived from the oxidation of Ib showed an electrical conductivity of 10-5 S cm-1. The polyradical 1 satisfies both an alternant but non-Kekulé-type π-conjugation and ferromagnetic connectivity of the unpaired electrons of the pendant phenoxyls. 1 with a spin concentration of 0.3 spin/unit displayed a spin quantum number (S) value of 2/2 to %, indicating a highspin ground state and an intramolecular ferromagnetic spin coupling through the polythiophene backbone.
|出版ステータス||Published - 2000|
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