Adsorption-Induced Distortion of F_{16}CuPc on Cu(111) and Ag(111): An X-ray Standing Wave Study

TL;DR

This study uses X-ray standing waves to analyze how F_{16}CuPc molecules adsorb on Cu(111) and Ag(111), revealing distorted, non-planar configurations with element-specific positional data and insights into molecular rehybridization.

Contribution

It provides detailed, element-specific adsorption geometries of F_{16}CuPc on metal surfaces, including non-dipolar corrections, advancing understanding of molecule-surface interactions.

Findings

Molecules adsorb in a lying, distorted configuration.

Central carbon rings are 2.61 Å (Cu) and 3.25 Å (Ag) above substrates.

Outer fluorine atoms are slightly further from the surface.

Abstract

The adsorption geometry of perfluorinated copper-phthalocyanine molecules (F_{16}CuPc) on Cu(111) and Ag(111) is studied using X-ray standing waves. A detailed, element-specific analysis taking into account non-dipolar corrections to the photoelectron yield shows that on both surfaces the molecules adsorb in a lying down, but significantly distorted configuration. While on copper (silver) the central carbon rings reside 2.61 Angstroem (3.25 Angstroem) above the substrate, the outer fluorine atoms are located 0.27 Angstroem (0.20 Angstroem) further away from the surface. This non-planar adsorption structure is discussed in terms of the outer carbon atoms in F_{16}CuPc undergoing a partial rehybridization (sp^2 --> sp^3).