Recoil lineshapes in hard X-ray photoelectron spectra of large molecules - free and anchored-on-surface 10-aminodecane-1-thiol

: Kukk Edwin, Püttner Ralph, Simon Marc

Publisher: ROYAL SOC CHEMISTRY

: 2022

: Physical Chemistry Chemical Physics

: PHYSICAL CHEMISTRY CHEMICAL PHYSICS

: PHYS CHEM CHEM PHYS

: 24

: 17

: 10465

: 10474

: 10

: 1463-9076

: 1463-9084

DOI: https://doi.org/10.1039/d1cp05777d

: https://pubs.rsc.org/en/content/articlelanding/2022/CP/D1CP05777D

Core-level photoelectron spectroscopy of molecules presents unique opportunities but also challenges in the Hard X-ray Spectroscopy (HAXPES) realm. Here we focus on the manifestation of the photoelectron recoil effects in core-level photoemission spectra, using the independent normal-mode oscillators approach that allows to model and investigate the resulting recoil lineshapes for molecules of large sizes with only a slight computational effort. We model the recoil lineshape for N 1s and C 1s photoemission using the 10-aminodecane-1-thiol molecule as an example. It represents also a class of compounds commonly used in creating self-assembled monolayers (SAMs) on surfaces. Attachment of the -SH head group to the surface is modelled here in a simplified way by anchoring the sulfur atom of a single molecule. The effects of the orientation of photoemission in the molecular frame on the recoil lineshape of such anchored molecules are illustrated and discussed as a possible geometry probe. Time-evolution of the recoil excitations from the initial emission site across the entire molecule is also visualized.