| AVS 62nd International Symposium & Exhibition | |
| Surface Science | Tuesday Sessions |
| Session SS+EN-TuA |
| Session: | Photocatalysis, Photochemistry, and Chirality at Surfaces |
| Presenter: | Gerson Mette, Universität Zürich, Switzerland |
| Authors: | G. Mette, Universität Zürich, Switzerland D. Sutter, Universität Zürich, Switzerland S. Schnidrig, Universität Zürich, Switzerland B. Probst, Universität Zürich, Switzerland R. Alberto, Universität Zürich, Switzerland J. Osterwalder, Universität Zürich, Switzerland |
| Correspondent: | Click to Email |
Within the search for new materials and methods for renewable energy resources, photocatalytic water splitting is a very promising field of study. In this framework, a polypyridine macrocycle was investigated which was already described in 1984 but only superficially examined [1]. It shares some similarities to porphyrins but with pyridyl subunits instead of pyrrol, hence the given trivial name: pyrphyrin. A high stability of the pyrphyrin and corresponding complexes is indicated due to its conjugation, planarity and cyclic nature. Furthermore, metal complexes based on pyrphyrin show promise as water reduction catalysts.
In this study, we examined the preparation of a pyrphyrin metal complex on a single crystalline surface in ultrahigh vacuum. In a first step, pyrphyrin coverages of approximately one monolayer and less, as determined by XPS measurements, were obtained by sublimation of the molecules on a Au(111) surface at room-temperature. By means of Low-Energy Electron Diffraction (LEED) and Scanning Tunneling Microscopy (STM), two distinct phases depending on the surface coverage were identified and structurally characterized. In a second step, deposition of Co metal at the level of 5% of a monolayer and subsequent annealing led to the formation of an almost complete monolayer of Co-ligated pyrphyrin molecules.
[1] S. Ogawa et al., J. Am. Chem. Soc. 1984, 106, 5760-5762.