Electrochemistry and electron transport properties of copolymers of electron deficient fluorenes with thiophene

Kavithaa Loganathan, Peter G. Pickup

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Copolymers of fluoren-9-one and (fluoren-9-ylidene)malononitrile with thiophene have been prepared by the electrochemical polymerization of 2-(2-thienyl)fluoren-9-one, 2,7-di(2-thienyl)fluoren-9-one, and (2,7-di(2-thienyl)fluoren-9-ylidene)malononitrile. 2-(2-Thienyl)fluoren-9-one gave polymer films with low conjugation lengths, indicating poorly defined coupling, while both monomers with two terminal thiophenes gave high quality copolymers. Poly-[2,7-di(2-thienyl)fluoren-9-one] was the most easily p-doped material, and gave the highest p-type conductivity of ca. 0.4 mS cm-1. In contrast poly-[(2,7-di(2-thienyl)fluoren-9-ylidene)malononitrile] was more easily reduced by over 0.5 V (formal potential = -0.60 V versus Ag/AgCl), and exhibited the higher n-type conductivity of ca. 6 μS cm-1. Comparisons between the three copolymers reveal differences in the mechanisms of p-type and n-type conduction, with the former dominated by hole transport along the polymer chains and the latter involving electron hopping between localized sites.

Original languageEnglish
Pages (from-to)4685-4690
Number of pages6
JournalElectrochimica Acta
Volume52
Issue number14
DOIs
Publication statusPublished - 1 Apr 2007
Externally publishedYes

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Keywords

  • Band gap
  • Conjugated copolymer
  • Electron transport
  • Fluorene
  • n-Doping

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

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