Spektroskopische Untersuchungen an auf Lanthanoid-Ionen basierten Einzelmolekülmagneten

• Antragsteller: Professor Dr. Joris van Slageren
• Fachliche Zuordnung: Anorganische Molekülchemie - Synthese, Charakterisierung ; Physikalische Chemie von Molekülen, Flüssigkeiten und Grenzflächen, Biophysikalische Chemie
• Förderung: Förderung von 2015 bis 2018
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 268285492

• Erstellungsjahr: 2017

Zusammenfassung der Projektergebnisse

This project made significant contributions to the understanding of the crystal field splitting in lanthanide-based single-molecule magnets. Single-molecule magnets are molecular species that display slow relaxation of the magnetization of purely molecular origin. They have been proposed as candidate materials for application in ultra-high density data storage devices. Slow relaxation of the magnetization in lanthanide complexes is intimately connected to the crystal field splitting, i.e. the interaction of the ligand electron density with the lanthanide f-electrons. In this work we have carried out in-depth magnetic analyses of the relaxation processes in such systems. Of particular interest is that we were able to elucidate the full electronic structure of lanthanide single-molecule magnets for the first time through a battery of advanced spectroscopic and magnetic methods. The main surprise was that the experimental determination and analysis of the full electronic structure is a highly challenging affair for which there are no standard recipes. This is in stark contrast with the situation for transition metal based systems. Thus for the erbium and dysprosium tetracarbonates good optical absorption data were obtained, but no high quality luminescence data. On the other hand, for the bpm-bridged dimers, luminescence data were obtained. However, for the polyoxometallates the data was good but insufficient for a full analysis. In the case of Dy3, optical measurements were not possible, but advanced magnetometry could be used.

Projektbezogene Publikationen (Auswahl)

• Comprehensive Spectroscopic Determination of the Crystal Field Splitting in an Erbium Single-Ion Magnet, J. Am. Chem. Soc., 137, 13114–13120 (2015)
  Y. Rechkemmer, J.E. Fischer, R. Marx, M. Dörfel, P. Neugebauer, S. Horvath, M. Gysler, T. Brock-Nannestad, W. Frey, M.F. Reid, J. van Slageren
  
• Magneto-optical investigations of molecular nanomagnet monolayers, Dalton Trans., 45, 7555 – 7558 (2016)
  J. Rozbořil, Y. Rechkemmer, D. Bloos, F. Münz, C.N. Wang, P. Neugebauer, J. Čechal, J. Novák, J. van Slageren
  
• Multitechnique investigation of Dy3 – Implications for Coupled Lanthanide Clusters, Chem. Sci., 7, 4347 – 4354 (2016)
  M. Gysler, F. El Hallak, L. Ungur, R. Marx, M. Hakl, P. Neugebauer, Y. Rechkemmer, Y. Lan, I. Sheikin, M. Orlita, C. Anson, A. K. Powell, R. Sessoli, L. Chibotaru J. van Slageren
  
• {NiII8LnIII6 } (Ln = Gd, Dy) rod-like nano-sized heteronuclear coordination clusters with a double carbonate bridge skeleton and remarkable MCE behaviour, Dalton Trans., 45, 8566 – 8572 (2016)
  E. Guarda, K. Bader, J. van Slageren, P. Alborés
  
• Chemical tunnel-splittingengineering in a dysprosium-based molelular nanomagnet, Nat. Commun., 9, 1292 (2018)
  M.A. Sørensen, U.B. Hansen, M. Perfetti, K.S. Pedersen, E. Bartolomé, G.G. Simeoni, H. Mutka, S. Rols, M. Jeong, I. Zivkovic, M. Retuerto, A. Arauzo, J. Bartolomé, S. Piligkos, H. Weihe, L.H. Doerrer, J. van Slageren, H.M. Rønnow, K. Lefmann, J. Bendix
  
• Exchange Coupling and Single Molecule Magnetism in Redox-active Tetraoxolene-bridged Dilanthanide Complexes, Chem. Sci., 9, 1221 – 1230 (2018)
  P. Zhang, M. Perfetti, M. Kern, P.P. Hallmen, L. Ungur, S. Lenz, M.R. Ringenberg, W. Frey, H. Stoll, G. Rauhut, J. van Slageren
  
• Magnetic Anisotropy Switch: Easy Axis to Easy Plane Conversion and Vice Versa, Adv. Funct. Mater.
  M. Perfetti, M.A. Sørensen, U.B. Hansen, H. Bamberger, S. Lenz, P.P. Hallmen, T. Fennell, G.G. Simeoni, A. Arauzo, J. Bartolomé, E. Bartolomé, K. Lefmann, H. Weihe, J. van Slageren, J. Bendix
  
• Measurement of Magnetic Exchange in Asymmetric Lanthanide Dimetallics: Toward a Transferable Theoretical Framework, J. Am. Chem. Soc., 140, 2504 – 2513 (2018)
  M.J. Giansiracusa, E. Moreno-Pineda, R. Hussain, R. Marx, M. Martínez Prada, P. Neugebauer, S. Al-Badran, D. Collison, F. Tuna, J. van Slageren, S. Carretta, T. Guidi, E.J.L. McInnes, R.E.P. Winpenny, N.F. Chilton