Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. Precise Control of Intramolecular Charge-Transport: The Interplay of Distance and Conformational Effects
 
research article

Precise Control of Intramolecular Charge-Transport: The Interplay of Distance and Conformational Effects

Schubert, Christina
•
Wielopolski, Mateusz  
•
Mewes, Lars-Hendrik
Show more
2013
Chemistry - A European Journal

A new series of donor–bridge–acceptor (D–B–A) compounds consisting of π-conjugated oligofluorene (oFL) bridges between a ferrocene (Fc) electron-donor and a fullerene (C60) electron-acceptor have been synthesized. In addition to varying the length of the bridge (i.e., mono- and bi-fluorene derivatives), four different ways of linking ferrocene to the bridge have been examined. The Fc moiety is linked to oFL: 1) directly without any spacer, 2) by an ethynyl linkage, 3) by a vinylene linkage, and 4) by a p-phenylene unit. The electronic interactions between the electroactive species have been characterized by cyclic voltammetry, absorption, fluorescence, and transient absorption spectroscopy in combination with quantum chemical calculations. The calculations reveal exceptionally close energy-matching between the Fc and the oFL units, which results in strong electronic-coupling. Hence, intramolecular charge-transfer may easily occur upon exciting either the oFLs or Fcs. Photoexcitation of Fc–oFL–C60 conjugates results in transient radical-ion-pair states. The mode of linkage of the Fc and FL bridge has a profound effect on the photophysical properties. Whereas intramolecular charge-separation is found to occur rather independently of the distance, the linker between Fc and oFL acts (at least in oFL) as a bottleneck and significantly impacts the intramolecular charge-separation rates, resulting in beta values between ßcs 0.08 and 0.19 Å-1. In contrast, charge recombination depends strongly on the electron-donor–acceptor distance, but not at all on the linker. A value of ßcr (0.35 ± 0.01 Å-1) was found for all the systems studied. Oligofluorenes prove, therefore, to be excellent bridges for probing how small structural variations affect charge transport in D–B–A systems.

  • Files
  • Details
  • Metrics
Loading...
Thumbnail Image
Name

7575_ftp.pdf

Access type

openaccess

Size

1008.58 KB

Format

Adobe PDF

Checksum (MD5)

a54bf26837e17d4a1e1ad59960754d85

Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés