4-hexylbithieno[3,2-b:2′3′-e]pyridine: An efficient electron-accepting unit in fluorene and indenofluorene copolymers for light-emitting devices

Sonar, P., Zhang, J., Grimsdale, A. C., Müllen, K., Surin, M., Lazzaroni, R., Leclère, P., Tierney, S., Heeney, M., & McCulloch, I. (2004) 4-hexylbithieno[3,2-b:2′3′-e]pyridine: An efficient electron-accepting unit in fluorene and indenofluorene copolymers for light-emitting devices. Macromolecules, 37(3), pp. 709-715.

View at publisher


4-Hexylbithienopyridine has been prepared as a novel electron-accepting monomer for conjugated polymers. To test its electronic properties, alternating copolymers with fluorene and indenofluorene polymers have been prepared. The copolymers displayed reduction potentials about 0.5 V lower than for the corresponding fluorene and indenofluorene homopolymers, indicating much improved electron-accepting properties. Analysis of the microscopic morphology of thin films of the copolymers by AFM shows that they lack the extensive supramolecular order seen with the homopolymers, which is attributed to the bithienopyridine units disrupting the π-stacking. LEDs using these polymers as the emitting layer produce blue-green emission with low turn-on voltages with aluminum electrodes confirming their improved electron affinity. The indenofluorene copolymer displayed an irreversible red shift in emission at high voltages, which is attributed to oxidation of the indenofluorene units. This red shift occurred at higher potentials than for indenofluorene homopolymers in LEDs, suggesting that the heterocyclic moieties offer some protection against electrically promoted oxidation.

Impact and interest:

27 citations in Scopus
Search Google Scholar™
50 citations in Web of Science®

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 75259
Item Type: Journal Article
Refereed: Yes
Keywords: Atomic force microscopy, Electrodes, Electronic properties, Fluorine compounds, Homopolymerization, Light emission, Oxidation, Reduction, Supramolecular chemistry, Electron accepting unit, Hexylbithienol pyridine, Indenofluorene copolymers, Copolymers
DOI: 10.1021/ma035329u
ISSN: 00249297 (ISSN)
Divisions: Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Copyright Owner: Copyright 2004 American Chemical Society
Deposited On: 29 Oct 2014 05:24
Last Modified: 30 Oct 2014 03:08

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page