The influence of modification by nitric acid or chlorine on the regiospecific structure of poly(3-alkylthiophenes) (P3ATs)

• Published in: Synthetic metals Vol. 74; no. 3; pp. 235 - 239
• Main Authors: Kreja, L., Kurzawa, M., Kurzawa, J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.10.1995; Amsterdam Elsevier Science; New York, NY
• Subjects: Applied sciences; Chemical modifications; Chemical reactions and properties; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Poly(3-alkylthiophene); Regiospecific structure; Regiospecific structure; Poly(3-alkylthiophene); Structure effect; Nitration; Chemical modification; Chlorination; Thiophene derivative polymer; Electrical conductor; Chlorine containing polymer; Experimental study; Regiospecificity
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/0379-6779(95)03388-Z

The nitric and chloro derivatives of chemically synthesized poly(3-alkylthiophenes) (P3ATs) were obtained by chemical modification using chlorine (Cl 2) or nitric acid (HNO 3). On the basis of spectral analyses (UV-Vis, IR, 1H NMR), elemental analysis and gel permeation chromatography (GPC), it was observed that the nitric group (−NO 2) was substituted in the 4- or 5-position of the thiophene ring of P3ATs. The −NO 2 group substitution in the 4- or 5-position of the thiophene ring depends on the regiospecific structure of the P3AT polymer chains. The substitution in the 4-position takes place in the head-to-tail sequence diad in polymer chains. The substitution of −NO 2 in the 5-position occurs in the head-to-head diad sequences and causes the degradation of the polymer chains. The modification of P3ATs by Cl 2 causes the substitution of the chlorine atom in the 4-position of the thiophene ring and in the β-position of the alkyl group. The chlorine substitution in the 4-position of the thiophene ring does not depend on the regiospecific structure of the polymer; however, the chlorine substitution in the β-position of the alkyl group takes place in the head-to-head diad sequences. Moreover, the modification of P3ATs using chlorine does not cause the polymer chain degradation.