Structure-dependent photophysics of first-generation phenyl-cored thiophene dendrimers

William J. Mitchell, Andrew J. Ferguson, Muhammet E. Kose, Benjamin L. Rupert, David S. Ginley, Gary Rumbles, Sean E. Shaheen, Nikos Kopidakis

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

We have prepared two series of first-generation thiophene-bridge dendrimers, with either three (3G1) or four (4G1) arms attached to a phenyl core, to elucidate their structure-property relationships. Optical properties were investigated with a combination of steady-state and time-resolved spectroscopic techniques. Steady-state spectroscopic data for the 3-arm dendrimers suggests that the exciton is delocalized over the a-conjugated thiophene segment and the phenyl core, but that the meta-linking of the dendrons prevents their electronic communication. In contrast, conjugation through the core to dendrons in the ortho and para positions is permitted in the 4-arm dendrimers, although the data suggest that the conjugation length does not extend over the full length of the a-conjugated sections of two coupled dendrons. This observation is due to Steric interactions between neighboring arms, which forces the arms to twist and bend out of the plane of the phenyl core, and is particularly prevalent in disrupting the conjugation through the ortho positions. As expected, our results show that an increase in the bridge length results in an increase in the conjugation length for both dendrimers, and a subsequent red-shift of the absorption and emission. In addition, an increase in the dendron length results in an increase in the Photoluminescence quantum yield and lifetime, suggesting that the ground and excited-state geometries are very similar and that the electronic transition is coupled to fewer vibrational modes.

Original languageEnglish
Pages (from-to)287-297
Number of pages11
JournalChemistry of Materials
Volume21
Issue number2
DOIs
Publication statusPublished - Jan 27 2009

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Dendrimers
Thiophenes
Thiophene
Quantum yield
Excited states
Excitons
Ground state
Photoluminescence
Optical properties
Geometry
Communication

ASJC Scopus subject areas

  • Materials Chemistry
  • Chemical Engineering(all)
  • Chemistry(all)

Cite this

Mitchell, W. J., Ferguson, A. J., Kose, M. E., Rupert, B. L., Ginley, D. S., Rumbles, G., ... Kopidakis, N. (2009). Structure-dependent photophysics of first-generation phenyl-cored thiophene dendrimers. Chemistry of Materials, 21(2), 287-297. https://doi.org/10.1021/cm802410d

Structure-dependent photophysics of first-generation phenyl-cored thiophene dendrimers. / Mitchell, William J.; Ferguson, Andrew J.; Kose, Muhammet E.; Rupert, Benjamin L.; Ginley, David S.; Rumbles, Gary; Shaheen, Sean E.; Kopidakis, Nikos.

In: Chemistry of Materials, Vol. 21, No. 2, 27.01.2009, p. 287-297.

Research output: Contribution to journalArticle

Mitchell, WJ, Ferguson, AJ, Kose, ME, Rupert, BL, Ginley, DS, Rumbles, G, Shaheen, SE & Kopidakis, N 2009, 'Structure-dependent photophysics of first-generation phenyl-cored thiophene dendrimers', Chemistry of Materials, vol. 21, no. 2, pp. 287-297. https://doi.org/10.1021/cm802410d
Mitchell, William J. ; Ferguson, Andrew J. ; Kose, Muhammet E. ; Rupert, Benjamin L. ; Ginley, David S. ; Rumbles, Gary ; Shaheen, Sean E. ; Kopidakis, Nikos. / Structure-dependent photophysics of first-generation phenyl-cored thiophene dendrimers. In: Chemistry of Materials. 2009 ; Vol. 21, No. 2. pp. 287-297.
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