Regensburg 2019 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 15: Metal Substrates II: Adsorption and Reactivity

O 15.3: Vortrag

Montag, 1. April 2019, 15:30–15:45, Kunsthalle

Following the products of a single intramolecular bond dissociation on surface — •Donato Civita, Grant James Simpson, and Leonhard Grill — Department of Physical Chemistry, University of Graz, Austria

Manipulation of molecules adsorbed at surfaces is very appealing to control and understand fundamental chemical processes. Chemical reactions can be triggered in single molecules by using a scanning tunneling microscope (STM). Specifically, chemical bonds within molecules can be cleaved [1], the resulting fragments can be pulled across the surface by lateral manipulation with the STM tip and even new bonds can be formed [2]. In this work, we study the dissociation of a single Br atom from a dibromoterfluorene (DBTF) molecule adsorbed on a Ag(111) surface. Experiments were done by applying voltage pulses with the STM tip on a single molecule at low temperatures (7 K). By imaging the single molecule before and after such a manipulation and, in addition, studying the current signal during the voltage pulse, we obtain insight into the process. Many dissociation experiments were recorded for different molecular isomers and different lateral locations of the voltage pulse over the molecule. A statistical analysis of the results reveals details about the dynamics of the dissociation, in particular the fate of the reaction products.

[1] B. C. Stipe, M. A. Rezaei, W. Ho, S. Gao, M. Persson, and B. I. Lundqvist, Phys. Rev. Lett. 78, 4410 (1997)

[2] K. Anggara, L. Leung, M. J. Timm, Z. Hu and J. C. Polanyi, Science Advances, EAAU2821 (2018)