The effect of fluorination on the surface structure of truxenones

Abstract

The surface structure of partially fluorinated truxenone (F3-truxenone) molecules on Cu (111) has been probed using a combination of scanning tunneling microscopy (STM) and low energy electron diffraction (LEED).

Quantitative Insights into the Adsorption Structure of Diindeno[1,2-a;1′,2′-c]fluorene-5,10,15-trione (Truxenone) on a Cu(111) Surface Using X-ray Standing Waves

“…It is possible, therefore, that the O atoms of each molecule exhibit slightly different adsorption heights within the (8 × 8) mesh and that the vector between the O atoms do not align with a ⟨211⟩ direction. The presence of large quantities of a disordered phase is also unlikely as previous STM studies of truxenone 16,24 and its fluorinated derivative 12 show stable island formation at room temperature and sub-monolayer coverage.…”

“… 8 − 11 Addition of electronegative fluorine atoms to the perimeter of truxenone also influences its surface adsorption properties. 12 Truxenone derivatives have also been used to construct covalent–organic frameworks for use as battery cathodes 13 and create oligomeric semiconducting materials. 14 The preceding examples show that truxenones are both interesting and useful as discrete molecules and as building blocks in organic and materials chemistry.…”

Epitaxial Templating of C60 with a Molecular Monolayer

“…Our recent work has established that truxenone molecules (Figure 1a inset) form a commensurate 8 × 8 structure on the Cu (111) surface at room temperature. 16,17 The pro-chiral nature of truxenone means that surface induced enantiomers are possible when supported by a surface, but these cannot be discriminated between in our experiments. 16 Consequently, no obvious "handedness" is observed in the supramolecular arrangement creating the pores although an achiral surface cannot be established.…”

“…Our recent work has established that truxenone molecules (Figure a inset) form a commensurate 8 × 8 structure on the Cu (111) surface at room temperature. , STM images of small (a) and large (c) areas of the truxenone/Cu (111) evaporated on to clean Cu (111) in ultrahigh vacuum (UHV) [full experimental procedures are present in the Supporting Information] are shown in Figure along with a LEED pattern (b) of the same surface recorded at 13 eV. This arrangement of molecules effectively creates an ordered array of open pores, approximately 0.7 nm in diameter and exactly 2.04 nm apart, aligned with the principal lattice vectors of the substrate.…”

“…Our recent work has demonstrated that truxenones, a family of 3-fold symmetric organic semiconductors, selfassemble to form epitaxial open-pored structures on Cu (111), a highly unusual observation in semiconducting organic molecules. 16,17 Combining truxenone and Cu (111) allows the creation of model surfaces to understand directed assembly behavior while employing a material system that is relevant for high performance device applications such as organic photovoltaics. 18−20 Through a combination of STM (Scanning tunnelling microscopy) and LEED (Low energy electron diffraction), we demonstrate that a modified C 60 layer forms within the pores of the truxenone network, exhibiting an 8 × 8 unit mesh with respect to the underlying Cu(111) surface.…”