title: Self-organized monolayer of meso-tetradodecylporphyrin coordinated to Au(111).
abstract: The structure of molecular monolayers formed at the interface between atomically flat surfaces and a solution of free-base meso-tetradodecylporphyrins (H2Ps) was examined by scanning tunneling microscopy (STM) at the liquid/solid interface. On the surface of graphite (HOPG), H2Ps form a well-ordered monolayer characterized by an oblique unit cell. On Au(111), H2Ps form a self-organized monolayer comprised of two distinct domain types. In both types of domains, the density of the porphyrin cores is increased in comparison to the arrangement observed on HOPG. Also, high-resolution STM images reveal that, in contrast to what is observed on HOPG, physisorption on Au(111) induces a distortion of the porphyrin macrocycle out of planarity. By using X-ray photoelectron spectroscopy, we demonstrate that this is likely to be due to the coordination of the lone pairs of the iminic (-C=N-) nitrogen atoms of the porphyrin macrocycle to Au(111).
authors.affiliation: Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Katsonis
authors.forename: Javier
authors.initials: J
authors.lastname: Vicario
authors.forename: Tibor
authors.initials: T
authors.lastname: Kudernac
authors.forename: Johan
authors.initials: J
authors.lastname: Visser
authors.forename: Michael M
authors.initials: MM
authors.lastname: Pollard
authors.forename: Ben L
authors.initials: BL
authors.lastname: Feringa
mesh_terms: D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling; D010316:Particle Size; D011166:Porphyrins / Q000737:chemistry*; D013499:Surface Properties; D014965:X-Rays
chemical_list: D011166:Porphyrins; C516601:meso-tetradodecylporphyrin; D006046:Gold; D006108:Graphite