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arXiv · 1809.09229

Correlation of Kondo effect and molecular conformation of the acceptor molecule in the TTF-TCNE charge transfer complex

Paul Stoll·Christian Lotze·Janina N. Ladenthin·Tobias R. Umbach·Isabel Fernandez-Torrente·Katharina J. Franke
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Abstract

A Kondo resonance has been observed on purely organic molecules in several combinations of charge transfer complexes on a metal surface. It has been regarded as a fingerprint of the transfer of one electron from the donor to the extended $\pi$ orbital of the acceptor's LUMO. Here, we investigate the stoichiometric checkerboard structure of tetrathiafulvalene (TTF) and tetracyanoethylene (TCNE) on a Au(111) surface using scanning tunneling and atomic force microscopy at 4.8 K. We find a bistable state of the TCNE molecules with distinct structural and electronic properties. The two states represent different conformations of the TCNE within the structure. One of them exhibits a Kondo resonance, whereas the other one does not, despite of both TCNE types being singly charged.

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Paul Stoll, Christian Lotze, Janina N. Ladenthin, Tobias R. Umbach, Isabel Fernandez-Torrente, Katharina J. Franke. 2018-09-24. Correlation of Kondo effect and molecular conformation of the acceptor molecule in the TTF-TCNE charge transfer complex. https://doi.org/10.1088/1361-648x/aae502

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