Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 5: Organic-Inorganic Hybrid Systems and Organic Films I

O 5.4: Vortrag

Montag, 20. März 2017, 11:15–11:30, WIL A317

Metastable tautomers — tuning the lifetime with an STM tip — •Andreas Krönlein¹, Jens Kügel¹, Aimee Sixta^1,2, Markus Böhme¹, and Matthias Bode^1,3 — ¹Physikalisches Institut, Universität Würzburg, 97074 Würzburg, Germany — ²University of Texas at Austin, 78712 Austin, Texas, United States — ³Wilhelm Conrad Röntgen Center for Complex Material Systems (RCCM), Universität Würzburg, 97074 Würzburg, Germany

Although the influence of an scanning tunneling microscopy tip is often considered to be negligible, there are many examples where the tip is strongly affecting the physical properties of the probed system, as, for example, shown for the excitation spectra of Fe-OEP-Cl molecules [1]. Here, we present a detailed study of the tautomerization of dehydrogenated phthalocyanine molecules on a Ag(111) surface by means of scanning tunneling microscopy and STM-based pump-and-sample experiments [2]. Our data reveal that the molecule can switch between four different tautomeric forms. Whereas two of tautomers exhibit a very long lifetime, the lifetime of the other two tautomers amounts to seconds only. Current- and bias-dependent studies indicate that the presence of the STM tip modifies the potential barrier, thereby allowing for a controlled tuning of the metastable tautomer’s lifetime.
B. W. Heinrich et al., Nature Physics 9, 765 (2013)
J. Kügel et al., ACS Nano in press