Physikalische Chemie - Direktor: Prof. Dr. Martin Wolf
Special Seminar
Host: T. Kumagai

Friday, September 7, 2018, 11:00 am
PC Seminar Room, G 2.06, Faradayweg 4
Dr. Borja Cirera
Instituto Madrileño de Estudios Avanzados [IMDEA] — Nanosciencia
On-Surface Design of Lanthanide-Based Nanoarchitectures
Lanthanide-directed nanoarchitectures on surfaces are envisioned to have large impact in a wide variety of fields such as luminescence, magnetism, sensing or catalysis. In order to design surface-confined nanomaterials to exploit these properties, two different coordinative supramolecular approaches will be addressed.
First, surface-confined metal-organic networks via lateral coordination of lanthanides with ditopic carboxilate organic linkers on Cu(111) are investigated. By selecting different lanthanide ions (Dy or Gd) and organic building blocks (TDA, PDA or TPA), both the node geometry or intermodal distance within the supramolecular lattices can be tuned.
Second, the metallation with dysprosium ions of two porphyrinoid species with distinct cavity size is described. On one hand, expanded porphyrinoids (HTAP) show promising results for long-term information storage by single molecule tip-induced deprotonation, while demonstrating that their large macrocycle can complexate lanthanides in an off-centered fashion. On the other hand, the deposition of Dy on top of a submonolayer of fluorinated tetraphenyl porphyrin species on Au(111) affords the expression of three different Dy-derived compounds. They are identified as the initial, intermediate and final metallated states, evidencing that such tetrapyrroles cannot host dysprosium ions in the main macrocyclic plane, but beneath it. Importantly, the initial metallated complexes show a narrow zero bias resonance at the Fermi level that is assigned to a molecular Kondo resonance with Tk ≈ 120 K, which can be switched off by means of vertical manipulation.
Our results provide hitherto protocols to design new lanthanide-based nanoarchitectures on surfaces, opening a new arena to exploit their technologically relevant properties.