LAUSR

To explore the possibility of tuning the oxidation state of a coordinated metal ion in an adsorbed tetrapyrrole complex by a minor modification of the ligand structure, multilayers and monolayers of 3H-hexaethyl-dimethyl-corrole (3H-HEDMC) on Ag(111) were in situ metalated under ultrahigh vacuum (UHV) conditions and subsequently analyzed with spectroscopic and microscopic methods. The metalation reaction leads to the formation of Fe(III)-hexaethyl-dimethyl-corrole (Fe-HEDMC). The results were compared with those for Fe-octaethyl-porphyrin (Fe-OEP), in which the Fe metal center has a formal Fe(+II) character. The analysis of the nearly unperturbed iron-corrole in the multilayer regime with X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy shows that the electronic structure of the corrole-coordinated iron is consistent with an Fe(+III) state in Fe-HEDMC. In the monolayers, the Fe centers in Fe-HEDMC and Fe-OEP interact similarly with the Ag(111) surf...