Coverage‐ and Temperature‐Dependent Metalation and Dehydrogenation of Tetraphenylporphyrin on Cu(111) |
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| Authors: | Michael Röckert Matthias Franke Quratulain Tariq Stefanie Ditze Michael Stark Patrick Uffinger Daniel Wechsler Upendra Singh Dr Jie Xiao Dr Hubertus Marbach Prof?Dr Hans‐Peter Steinrück Dr Ole Lytken |
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| Affiliation: | Lehrstuhl für Physikalische Chemie II, Universit?t Erlangen‐Nürnberg, Egerlandstra?e 3, 91058 Erlangen (Germany), Fax: (+49)?9131‐85‐28867 |
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| Abstract: | 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, stepwise partial dehydrogenation, and finally complete dehydrogenation. At low coverage the reactions are independent of coverage, but at higher coverage metalation becomes faster and partial dehydrogenation slower. This behavior is explained by a weaker interaction between the iminic nitrogen atoms and the Cu(111) surface in the high‐coverage checkerboard structure, leading to faster metalation, and the stabilizing effect of T‐type interactions in the CuTPP islands formed at high coverage after metalation, leading to slower dehydrogenation. Based on the amount of hydrogen released and the appearance in STM, a structure of the partially dehydrogenated molecule is suggested. |
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| Keywords: | copper porphyrinoids self‐metalation temperature‐programmed desorption X‐ray photoelectron spectroscopy |
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