Molecular Conformation, Organizational Chirality, and Iron Metalation of meso-Tetramesitylporphyrins on Copper(100)

Abstract

We report on the conformation and self-assembly properties of meso-tetramesitylporphyrin on Cu(100). The results show that the presence of the mesityl groups limits the interaction between the porphyrin ring and the copper surface, contributing to the high porphyrin mobility at room temperature. At low temperatures it is the substrate which determines the molecule orientation. The intermolecular interaction is also very weak, and only for high coverages do the porphyrins self-assemble to form large islands with two different mirror symmetric unit cells. The porphyrins can be Fe metalated by sublimation of Fe at room temperature on a porphyrin overlayer deposited on the copper surface.

Surface chemistry of porphyrins and phthalocyanines

“…22b is obviously not identical to its mirror image, indicating local organizational chirality of this structure. Similar observations have been made for many other (metallo)tetraphenylporphyrins on metal surfaces [397], including systems where the phenyl rings carried additional substituents [399] or when strong adsorbate-substrate interactions were present [385] (see this section above). Since the self-organization is dominated by the periphery of the porphyrin, rather than by the substrate or the metal center [383], structures of other combinations of metalloporphyrins and metal surfaces are often not very different from the structure of the prototypical CoTPP on Ag(1 1 1).…”

Self-metalation of 2H-tetraphenylporphyrin on Cu(111): An x-ray spectroscopy study

“…[30][31][32][33][34] In this work the selfmetalation, i.e., the metalation of adsorbed free-base porphyrins by substrate atoms, is studied. 2H-TPP layers of different thicknesses were prepared on the Cu(111) surface.…”

“…29 Alternatively it is possible to evaporate free-base porphyrins and metalate them directly on the surface which allows to prepare films of metalloporphyrins whose instability or reactivity prevent a direct evaporation. The metalation so far mainly has been realized by vapor deposition of free-base porphyrins and metal atoms including Fe [30][31][32] , Zn 33 , Co 34 , Ni 35 and Ce 36,37 . A different approach is the self-metalation at the porphyrin-substrate 3 interface, i.e., the metalation of the free-base porphyrins with surface atoms without utilizing additionally evaporated metal atoms.…”

Molecular chirality at surfaces

“…Typical examples are porphyrins and phthalocyanines [81][82][83][84]. These C 4 v symmetric molecules achieve their densest structures when arranged in a CW or CCW fashion (Fig.…”