Tetrathiafulvalene-Tetracyanoquinodimethane Charge-Transfer Complexes Wired to Carbon Surfaces: Tuning of the Degree of Charge Transfer

Abstract : Charge-transfer complexes involving tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) derivatives are engineered in a 2D arrangement onto a carbon surface through the exposure of immobilized TTF units to TCNQ compounds. TTF molecules were immobilized as robust monolayers on carbon surfaces using the electrografting method followed by a click chemistry coupling. When the TTF monolayer is exposed to TCNQ TCNQF(2) (2,5-difluoroTCNQ), and TCNQF4 (2,3,5,6-tetrafluoro-TCNQ), strong donor acceptor complexes are formed onto the surface. A considerable decrease of the electrochemical response accompanies the formation of the charge-transfer complex. This observation is rationalized by the analysis of original crystal samples using an ultramicroelectrode cavity, confirming that charge transfer complexes are electrochemically silent. A fine control of the degree of charge transfer with the judicious choice of different acceptors is evidenced through electrochemical and X-ray photoelectron spectroscopy (XPS) measurements. Thus, donor acceptor complexes of different natures are formed. A fully ionic charge-transfer complex is formed upon exposure of the TTF monolayer to the more oxidizing TCNQF(4), while a neutral complex is obtained after exposure to the less oxidizing TCNQ, Exposition of the TTF monolayers to the intermediate TCNQF(2) yields a mixture of neutral-ionic systems. These donor acceptor interactions that fully mimic those described in the solid state are rarely described in such a 2D arrangement, with systems being directly wired to an electrode.
Document type :
Journal articles
Complete list of metadatas

Cited literature [14 references]  Display  Hide  Download

https://hal-univ-rennes1.archives-ouvertes.fr/hal-01438122
Contributor : Laurent Jonchère <>
Submitted on : Monday, April 10, 2017 - 11:26:21 AM
Last modification on : Saturday, December 22, 2018 - 7:32:40 PM
Long-term archiving on : Tuesday, July 11, 2017 - 12:46:13 PM

File

Jalkh et al. - 2016 - Tetrathi...
Files produced by the author(s)

Identifiers

Citation

Joanna Jalkh, Yann R. Leroux, Antoine Vacher, Dominique Lorcy, Philippe Hapiot, et al.. Tetrathiafulvalene-Tetracyanoquinodimethane Charge-Transfer Complexes Wired to Carbon Surfaces: Tuning of the Degree of Charge Transfer. Journal of Physical Chemistry C, American Chemical Society, 2016, 120 (49), pp.28021--28030. ⟨10.1021/acs.jpcc.6b09459⟩. ⟨hal-01438122⟩

Share

Metrics

Record views

168

Files downloads

95