title: Coverage- and temperature-dependent metalation and dehydrogenation of tetraphenylporphyrin on Cu(111).
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.
authors: Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen (Germany), Fax: (+49) 9131-85-28867.
authors: Michael
authors: M
authors: Röckert
authors: Matthias
authors: M
authors: Franke
authors: Quratulain
authors: Q
authors: Tariq
authors: Stefanie
authors: S
authors: Ditze
authors: Michael
authors: M
authors: Stark
authors: Patrick
authors: P
authors: Uffinger
authors: Daniel
authors: D
authors: Wechsler
authors: Upendra
authors: U
authors: Singh
authors: Jie
authors: J
authors: Xiao
authors: Hubertus
authors: H
authors: Marbach
authors: Hans-Peter
authors: HP
authors: Steinrück
authors: Ole
authors: O
authors: Lytken
mesh_terms: D003300:Copper / Q000737:chemistry*; D006865:Hydrogenation; D008665:Metalloporphyrins / Q000737:chemistry; D016252:Microscopy, Scanning Tunneling; D056951:Photoelectron Spectroscopy; D011166:Porphyrins / Q000737:chemistry*; D013696:Temperature
chemical_list: D008665:Metalloporphyrins; D011166:Porphyrins; C441604:meso-tetra(4-sulphonatophenyl)porphyrinato copper(II); C409084:tetraphenylporphyrin; D003300:Copper
keywords: X-ray photoelectron spectroscopy; copper; porphyrinoids; self-metalation; temperature-programmed desorption