• Pennino, Umberto Del
• Affronte, Marco
• Renzi, Valentina De
• Corradini, Valdis
• Gambardella, Alessandro
• Biagi, Roberto
• Timco, Grigore A.
• Winpenny, Richard E. P.
• Muryn, Christopher

Abstract

<p>A study of the deposition of heterometallic antiferromagnetically coupled rings onto gold surfaces is reported. Two new {Cr₇Ni} rings, [NH ₂ⁿPr₂][Cr₇NiF₈(3-tpc) ₁₆] (1) (where 3-tpc = 3-thiophenecarboxylate) and [ ⁿBuNH₂CH₂CH₂SH] [Cr ₇NiF₈(O₂C^tBu)₁₆] (2) have been made and structurally characterized. They have been deposited from the liquid phase on Au(111) and the adsorbed molecules compared by means of scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS). In both cases a two-dimensional distribution of individually accessible {Cr ₇Ni} heterometallic rings on the gold surface has been obtained, exploiting the direct grafting of sulfur-functionalized clusters. There is a competition between the chemisorption of the {Cr₇Ni} clusters and a thiolic self-assembled monolayer (SAM) formed by free ligands. In 2, the presence of a single sulfur ligand should force the molecule to graft with the ring axis normal to the surface. The cluster stability in the STM images and the S-2p energy positions demonstrate, for both functionalizations, the strength of the grafting with the gold surface.</p>

Topics

• Deposition
• impedance spectroscopy
• surface
• cluster
• x-ray photoelectron spectroscopy
• gold
• strength
• two-dimensional
• functionalization
• liquid phase
• scanning auger microscopy
• scanning tunneling microscopy