Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 3: Scanning Probe Techniques: Method Development I
O 3.2: Vortrag
Montag, 20. März 2017, 10:45–11:00, TRE Phy
Tip-induced vs. thermal dehalogenation of 4-bromo-3''-iodo-p-terphenyl on Cu(111) — •Qigang Zhong1,2, Daniel Ebeling1, Tobias Schlöder3, Sebastian Ahles4, Lifeng Chi2, Doreen Mollenhauer3, Hermann A. Wegner4, and André Schirmeisen1 — 1Institute of Applied Physics, Justus-Liebig University, Giessen, Germany — 2Institute of Functional Nano & Soft Materials, Soochow University, Suzhou, P. R. China — 3Institute of Physical Chemistry, Justus-Liebig University, Giessen, Germany — 4Institute of Organic Chemistry, Justus-Liebig University, Giessen, Germany
Dehalogenation is an important step in Ullmann reaction, which is widely used in on-surface synthesis of various functional polymers. Controlled stepwise dehalogenation will help to build more refined and customized molecular structures. However, there are few investigations on the sequential dehalogenation process so far, especially at the atomic scale. Here, we evaporated 4-bromo-3''-iodo-p-terphenyl (BITP) molecules onto a cold Cu(111) surface (Tsam < 150 K). Subsequently, single-molecule deiodination and debromination reactions were triggered either by applying different voltage pulses above iodine and bromine substituents or by heating the sample substrate. The adsorption structures of the obtained radicals were characterized via low temperature non-contact atomic force microscopy (LT-NC-AFM) with sub-molecular resolution. The distinct pulse voltages needed for deiodination and debromination coincide with the difference in bond cleavage temperatures for iodine and bromine substituents.