Controlled Metalation of Self‐Assembled Porphyrin Nanoarrays in Two Dimensions

Abstract

We report a bottom-up approach for the fabrication of metallo-porphyrin compounds and nanoarchitectures in two dimensions. Scanning tunneling microscopy and tunneling spectroscopy observations elucidate the interaction of highly regular porphyrin layers self-assembled on a Ag(111) surface with iron monomers supplied by an atomic beam. The Fe is shown to be incorporated selectively in the porphyrin macrocycle whereby the template structure is strictly preserved. The immobilization of the molecular reactants allows the identification of single metalation events in a novel reaction scheme. Because the template layers provide extended arrays of reaction sites, superlattices of coordinatively unsaturated and magnetically active metal centers are obtained. This approach offers novel pathways to realize metallo-porphyrin compounds, low-dimensional metal-organic architectures and patterned surfaces which cannot be achieved by conventional means.

Studying the dynamic behaviour of porphyrins as prototype functional molecules by scanning tunnelling microscopy close to room temperature

“…4,32,35,36,56,58,[72][73][74][75][76][77][78][79][80][81][82][83][84][85] It is nowadays well established that metalloporphyrins can be synthesised readily on a metal surface by the reaction of a corresponding free base porphyrin with an ''available'' metal atom. The respective metal atom can be provided on the surface by pre-or postdeposition, or originate from the surface itself.…”

“…Depending on the metal, this in situ metalation can proceed already at room temperature or after moderate annealing. 72,73,83 It was studied in detail for 2HTPP with Co, 4 …”

Cis-dicarbonyl binding at cobalt and iron porphyrins with saddle-shape conformation

“…The bending of opposing pyrrole groups leads to a characteristic imaging of the macrocycle as a triple protrusion when occupied states are probed. 11,12,20 Its core part reflects the metal center, which is flanked by the two α-pyr moieties. On Ag(111), CoTPP forms regular arrays (see Fig.…”

Two-Dimensional Nanotemplates as Surface Cues for the Controlled Assembly of Organic Molecules

“…A porphyrin nanoarray was employed as the key component of a novel reaction scheme for the formation of metalloporphyrin nanoarrays, with the metal being provided by an atomic beam [99]. Iron atoms react with tetrapyridyl-porphyrin (TPyP) molecules ordered in a staggered arrangement on Ag(111) surface, to give the compound Fe-TPyP.…”