title: Preserving charge and oxidation state of Au(III) ions in an agent-functionalized nanocrystal model system.
abstract: Supporting functional molecules on crystal facets is an established technique in nanotechnology. To preserve the original activity of ionic metallorganic agents on a supporting template, conservation of the charge and oxidation state of the active center is indispensable. We present a model system of a metallorganic agent that, indeed, fulfills this design criterion on a technologically relevant metal support with potential impact on Au(III)-porphyrin-functionalized nanoparticles for an improved anticancer-drug delivery. Employing scanning tunneling microscopy and -spectroscopy in combination with photoemission spectroscopy, we clarify at the single-molecule level the underlying mechanisms of this exceptional adsorption mode. It is based on the balance between a high-energy oxidation state and an electrostatic screening-response of the surface (image charge). Modeling with first principles methods reveals submolecular details of the metal-ligand bonding interaction and completes the study by providing an illustrative electrostatic model relevant for ionic metalorganic agent molecules, in general.
authors: Institute of Semiconductor and Solid State Physics, Centre for Nanobionics and Photochemical Sciences (CNPS), Johannes Kepler University, 4040 Linz, Austria. stefan.muellegger@jku.at
authors: Stefan
authors: S
authors: Müllegger
authors: Wolfgang
authors: W
authors: Schöfberger
authors: Mohammad
authors: M
authors: Rashidi
authors: Thomas
authors: T
authors: Lengauer
authors: Florian
authors: F
authors: Klappenberger
authors: Katharina
authors: K
authors: Diller
authors: Kamuran
authors: K
authors: Kara
authors: Johannes V
authors: JV
authors: Barth
authors: Eva
authors: E
authors: Rauls
authors: Wolf Gero
authors: WG
authors: Schmidt
authors: Reinhold
authors: R
authors: Koch
mesh_terms: D004337:Drug Carriers / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008024:Ligands; D053768:Metal Nanoparticles / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D008024:Ligands; D008665:Metalloporphyrins; D011166:Porphyrins; D006046:Gold; C049692:tetraphenylporphine