Regensburg 2007 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 44: Poster Session II (Semiconductors; Oxides and Insulators: Adsorption, Clean Surfaces, Epitaxy and Growth; Surface Chemical Reactions and Heterogeneous Catalysis; Surface or Interface Magnetism; Solid-Liquid Interfaces; Organic, Polymeric, Biomolecular Films; Particles and Clusters; Methods: Atomic and Electronic Structure; Time-resolved Spectroscopies)

O 44.5: Poster

Mittwoch, 28. März 2007, 17:00–19:30, Poster C

In-situ synthesis and reactivity of adsorbed iron(II) and cobalt(II) tetraphenylporphyrins — •Yun Bai, Sven Schöffel, Ken Flechtner, Liam Bradshaw, Hans-Peter Steinrück, and J. Michael Gottfried — Universität Erlangen-Nürnberg, Lehrstuhl für Physikalische Chemie II, Egerlandstr. 3, 91058 Erlangen, Germany

In biological systems, Fe and Co porphyrins play an important role as the active centers of enzymes. Our approach to studying their reactivity is based on well ordered monolayers of these planar metal complexes at a Ag(111) surface. Their reactions with biologically relevant molecules such as O₂ and NO were studied under ultrahigh vacuum conditions with photoelectron spectroscopy and related techniques. Experimental difficulties arise from the extreme oxidation sensitivity of the Fe(II)-porphyrins. Therefore, the commonly employed ex-situ synthesis of the metalloporphyrin and subsequent vacuum deposition was ruled out as a way to prepare Fe(II)-porphyrin monolayers. Instead, we used an approach recently developed for the in-situ synthesis of adsorbed Co(II)-tetraphenylporphyrin [1] and succeeded to metalate monolayers of tetraphenylporphyrin with stoichiometric amounts of vapor-deposited Fe atoms. Supported by the Deutsche Forschungsgemeinschaft through SFB 583.

[1] Gottfried et al., J. Am. Chem. Soc. 2006, 128, 5644.