Synthesis of End-capped Regioregular Poly(3-hexylthiophene)s via Direct Arylation

• Published in: Macromolecular rapid communications. Vol. 33; no. 14; pp. 1203 - 1207
• Main Authors: Wang, Qifeng, Wakioka, Masayuki, Ozawa, Fumiyuki
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 26-07-2012; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: Applied sciences; Bromides - chemistry; direct arylation; end-capping; Exact sciences and technology; Molecular Structure; Molecular weight; Organic polymers; organometallic catalysts; Physicochemistry of polymers; Polymerization; Polymers; Polymers - chemical synthesis; Polymers - chemistry; Polymers with particular properties; polythiophenes; Preparation, kinetics, thermodynamics, mechanism and catalysts; Stereoisomerism; synthesis; Thiophenes - chemistry; One pot reaction; Arylation; Amino group; End group; Self condensation; Aromatic polymer; Bromocarbon; Palladium complex; Head to tail polymer; Dehydrobromination; Conjugated polymer; Thiophene derivative polymer; end-capping; Reaction mechanism; polythiophenes; Chloro complex; Functional group; synthesis; Catalytic reaction; Solution polycondensation; Experimental study; Monodispersed polymer; direct arylation; Preparation; Dinuclear complex; organometallic catalysts
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.201200076

The synthesis of regioregular head‐to‐tail poly(3‐hexylthiophene)s capped with aryl groups (Ar‐HT‐P3HTs) has been accomplished by palladium‐catalyzed polycondensation of 2‐bromo‐3‐hexylthiophene (1) via direct arylation. A variety of aryl groups are installed at the initiated end in 86%–98% selectivity using aryl bromides and iodides as capping agents. The polymerization proceeds via a two‐stage process. Before monomer 1 is consumed, the competitive formation of end‐capped and non‐capped HT‐P3HTs is operative, where the molecular weight increases linearly with monomer conversion. After 1 is consumed, the resulting polymers are coupled with each other to afford highly end‐capped HT‐P3HTs.
Highly regioregular head‐to‐tail poly(3‐hexylthiophene)s capped with aryl groups (Ar‐HT‐P3HTs) are synthesized by palladium‐catalyzed polycondensation of 2‐bromo‐3‐hexylthiophene (1) via direct arylation. A variety of p‐functionalized aryl groups are installed at the initiated end in 86%–98% selectivity, simply using aryl bromides or iodides as capping agents.