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O: Fachverband Oberflächenphysik
O 18: Poster Session II: Metal substrates II
O 18.3: Poster
Monday, March 1, 2021, 13:30–15:30, P
The influence of charge transfer on molecular structure and conformation at surfaces: TCNQ on metals — •Luke Rochford1, David Duncan1, Phil Woodruff2, and Reinhard Maurer2 — 1Diamond Light Source, UK — 2Warwick University, UK
Electron acceptors such as TCNQ are believed, based on previous studies, to adopt bent conformations when adsorbed on metal surfaces due to electron transfer. Our recent, quantitative, structural experiments show definitively that this is not the case on a variety of metal surfaces.
Our experimental work has combined powerful complimentary surface science techniques in the home lab with synchrotron light-based techniques, mainly synchrotron x-ray photoelectron spectroscopy (S-XPS) and x-ray standing waves (XSW). XSW has been central here, as it allows quantitative measurement out-of-plane structure of molecules with chemical specificity and sub-bond-length precision.
These data are supported by DFT calculations which show that dispersion force corrections are vital to properly reproduce our observed structures. The explicit inclusion of metal adatoms in structural models is also of key importance to explain our experimental observations.
This fundamental understanding has allowed us to understand the lateral charge transfer at work between native metal adatoms and electron acceptor molecules. We have applied this knowledge to design and create two-dimensional charge transfer salts using low concentrations of alkali metal atoms.