Coverage‐ and Temperature‐Dependent Metalation and Dehydrogenation of Tetraphenylporphyrin on Cu(111). Issue 29 (25th June 2014)

• Record Type: Journal Article
• Authors: Röckert, Michael; Franke, Matthias; Tariq, Quratulain; Ditze, Stefanie; Stark, Michael; Uffinger, Patrick; Wechsler, Daniel; Singh, Upendra; Xiao, Jie; Marbach, Hubertus; Steinrück, Hans‐Peter; Lytken, Ole
• Is Part Of: Chemistry. Volume 20:Issue 29(2014)
• Page Start: 8948
• Page End: 8953
• Publication Date: 2014-06-25
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201402420
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>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‐21<italic>H</italic>, 23<italic>H</italic>‐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.</p> </abstract>