Matthias Franke

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We show that both single-crystalline and nanostructured MgO surfaces convert free-base tetraphenyl porphyrin (2HTPP) into magnesium tetraphenyl porphyrin (MgTPP) at room temperature. The reaction can be viewed as an ion exchange between the two aminic protons of the 2HTPP molecule with a Mg(2+) ion from the surface. The driving force for the reaction is the(More)
We have investigated the interactions between cobalt(ii)-tetraphenylporphyrin (CoTPP) molecules and MgO(100) thin films on Ag(100) by means of Synchrotron Radiation X-Ray and Ultra-Violet Photoelectron Spectroscopy (SR-XPS and SR-UPS). At room temperature, the CoTPP monolayer consists of two different species. A minority of molecules exhibits a strong(More)
Controlling the metalation of surface porphyrins is a critical process in porphyrin-based devices. Indeed, surface porphyrins are known to metalate in ultrahigh vacuum from codeposited metal atoms or substrate atoms; however, it is not yet known if surface porphyrins could metalate from ions in solution, that is, the most likely environment for(More)
Demetalation of zinc 5,10,15,20-tetraphenylporphyrin (ZnTPP) under acidic conditions and ion exchange with Cu(2+) ions at neutral pH are both rapid reactions in the liquid medium. However, for ZnTPP monolayers adsorbed on a Au(111) surface exposed to aqueous solution, we find that, although ion exchange takes place rapidly as expected, demetalation does not(More)
Using temperature-programmed desorption, supported by X-ray photoelectron spectroscopy and scanning tunneling microscopy, a comprehensive overview of the main reactions of 5,10,15,20-tetraphenyl-21H,23H-porphyrin (2HTPP) on Cu(111) as a function of coverage and temperature is obtained. Three reactions were identified: metalation with Cu substrate atoms,(More)
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