FePc and FePcF 16 on Rutile TiO 2(110) and (100): Influence of the Substrate Preparation on the Interaction Strength

Molecules. 2019 Dec 13;24(24):4579. doi: 10.3390/molecules24244579.

Abstract

Interface properties of iron phthalocyanine (FePc) and perfluorinated iron phthalocyanine (FePcF16) on rutile TiO2(100) and TiO2(110) surfaces were studied using X-ray photoemission spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and low-energy electron diffraction (LEED). It is demonstrated that the interaction strength at the interfaces is considerably affected by the detailed preparation procedure. Weak interactions were observed for all studied interfaces between FePc or FePcF16 and rutile, as long as the substrate was exposed to oxygen during the annealing steps of the preparation procedure. The absence of oxygen in the last annealing step only had almost no influence on interface properties. In contrast, repeated substrate cleaning cycles performed in the absence of oxygen resulted in a more reactive, defect-rich substrate surface. On such reactive surfaces, stronger interactions were observed, including the cleavage of some C-F bonds of FePcF16.

Keywords: X-ray absorption; interfaces; iron phthalocyanine; photoemission; rutile.

MeSH terms

  • Ferrous Compounds / chemistry*
  • Halogenation
  • Indoles / chemistry*
  • Molecular Structure
  • Photoelectron Spectroscopy
  • Surface Properties
  • Titanium / chemistry*

Substances

  • Ferrous Compounds
  • Indoles
  • iron phthalocyanine
  • titanium dioxide
  • Titanium