Properties and structure of substituted poly(thiophene-2,5-diyl), poly(pyridine-2,5-diyl), and their analogues prepared by organometallic processes

• Published in: Synthetic metals 1993-01, Vol.55 (2), p.1214-1220
• Main Authors: Yamamoto, Takakazu, Miyazaki, Yuichi, Fukuda, Takashi, Zhou, Zhen-hua, Maruyama, Tsukasa, Kanbara, Takaki, Osakada, Kohtaro
• Format: Article
• Language: English
• Subjects: Applied sciences; Electrical, magnetic and optical properties; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/0379-6779(93)90227-N

Substituted poly(thiophene-2,5-diyl)s and poly(pyridine-2,5-diyl)s have been prepared by dehalogenative polycondensation of the corresponding dihaloaromatic compounds with zerovalent nickel coplexes. IR spectra of poly(3-alkylthiophene-2,5-diyl)s and poly(3-alkoxythiophene-2,5-diyl)s are essentially the same as those of the corresponding polymers prepared by chemical and electrochemical oxidation, and the polymers show high thermal stability. Poly(pyridine-2,5-diyl) PPy, poly(methylpyridine-2,5-diyl)s PMePy's, poly(2,2′-bipyridine-5,5′diyl) PBpy, and poly(quinolinediyl)s PQ's have the molecular weight ranging from 3200 to 82000. These polymers are easily converted into n-type conductors by electrochemical as well as chemical reduction. PPy and PBpy takes rigidly linear structure both in solutions and in the solid state, and strong dichroism is observed for stretched poly(vinyl alcohol)-PPy and -PBpy films.