Effects of branching position of alkyl side chains on ordering structure and charge transport property in thienothiophenedione- and quinacridone-based semiconducting polymers

Kohsuke Kawabata, Masahiko Saito, Noriko Takemura, Itaru Osaka, Kazuo Takimiya

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

To investigate the effect of the branching position of the alkyl groups on the side chain of semiconducting polymers, we synthesized two series of semiconducting polymers based on thienothiophene-2,5-dione (PTTD4Ts) and quinacridone (PQA2Ts). 2-Decyltetradecyl, 3-decylpentadecyl, 4-decylhexadecyl, and 5-decylheptadecyl groups were used, and the branching position was systematically varied from the second carbon from the backbone to the fifth carbon. These branched side chains are introduced into the thiophene ring for PTTD4Ts and the quinacridone unit for PQA2Ts. The polymer thin films exhibited small but clear differences in their optical absorption spectra, suggesting that the intermolecular interaction in the solid state varied based on the branching position. The grazing incident X-ray diffraction study revealed that the π-π stacking d-spacing of both polymers decreased when the branching position was moved away from the backbones, indicating that the intermolecular interaction was enhanced. Therefore, regardless of the core where the alkyl groups were introduced, the branching position effectively improved the ordering structure of the polymers, which was most likely due to suppressed steric hindrance. Although PTTD4Ts did not exhibit a clear correlation between the branching position and charge carrier mobility, the mobility of PQA2Ts gradually increased as the branching position moved away from the backbone.

Original languageEnglish
Pages (from-to)169-176
Number of pages8
JournalPolymer Journal
Volume49
Issue number1
DOIs
Publication statusPublished - 2017 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Polymers and Plastics
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Effects of branching position of alkyl side chains on ordering structure and charge transport property in thienothiophenedione- and quinacridone-based semiconducting polymers'. Together they form a unique fingerprint.

Cite this