Resolving intramolecular-distortion changes induced by the partial fluorination of pentacene adsorbed on Cu(111)

DOI: 10.1103/PhysRevMaterials.2.044002

Authors: Antoni Franco-cañellas (Institut für Angewandte Physik, Universität Tübingen) , Qi Wang (Institute of Functional Nano & Soft Materials (FUNSOM); Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University) , Katharina Broch (Institut für Angewandte Physik, Universität Tübingen) , Bin Shen (Institut für Organische Chemie, Universität Tübingen) , Alexander Gerlach (Institut für Organische Chemie, Universität Tübingen) , Holger F. Bettinger (Institut für Organische Chemie, Universität Tübingen) , Steffen Duhm (Institute of Functional Nano & Soft Materials (FUNSOM); Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University) , Frank Schreiber (Institut für Angewandte Physik, Universität Tübingen)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review Materials , VOL 2

State: Published (Approved)
Published: April 2018
Diamond Proposal Number(s): 12797

Abstract: We experimentally quantify the molecular bending of a partially fluorinated pentacene (PEN) compound, namely 2,3,9,10-tetrafluoropentacene (F4PEN), adsorbed on Cu(111). By means of the x-ray standing wave (XSW) technique, we directly measure the adsorption distance of three inequivalent carbon sites, the fluorine atoms as well as the total and backbone carbon average adsorption distances. The precise positioning of different sites within the carbon core allows us to resolve two adsorption behaviors, namely a PEN-like strong coupling between the backbone and the substrate, and a repulsive interaction involving the fluorinated short molecular edges, which are 0.91±0.09Å above the central benzene ring. This finding is further supported by additional electronic and in-plane-structure measurements, thus showing that the selective fluorination of a PEN molecule has only a local conformational effect and it is not sufficient to modify its interface properties. Yet, in the multilayer regime, the electronic and growth properties of the film differ completely from those of PEN and its perfluorinated derivative.

Journal Keywords: Surface & interfacial phenomena; Surface adsorption; Interfaces; Monolayer films; Organic semiconductors; Low-energy electron diffraction; Ultraviolet photoelectron spectroscopy; X-ray photoelectron spectroscopy; X-ray standing waves

Subject Areas: Materials


Instruments: I09-Surface and Interface Structural Analysis