(Invited) Bulk and Surface Magnetic Properties of Endohedral Metallofullerenes

Encapsulation of magnetic species within robust molecular containers is a natural route towards stable and processable single molecule magnets (SMMs). Air-stability, thermal stability, ability to form thin molecular layers on different substrates are among the critical issues to be addressed. Chemical and thermal stability of fullerenes makes them perfectly suitable for this goal. Fullerenes can encapsulate up to four metal atoms within their inner space, and a number of lanthanide EMFs was found to show SMM behavior.1-5 Besides, EMF-SMMs can form monolayers by sublimation6, 7 or by self-assembly from solution,8 and such monolayers retain their SMM properties on metallic substrates. In this contribution we will highlight recent developments in the field of lanthanide-EMFs with peculiar magnetic properties. 1. Spree, L.; Popov, A. A., Recent advances in single molecule magnetism of dysprosium-metallofullerenes. Dalton Trans. 2019, 48, 2861-2871. 2. Liu, F.; Spree, L.; Krylov, D. S.; Velkos, G.; Avdoshenko, S. M.; Popov, A. A., Single-Electron Lanthanide-Lanthanide Bonds Inside Fullerenes toward Robust Redox-Active Molecular Magnets. Acc. Chem. Res. 2019, 52, 2981-2993. 3. Liu, F.; Velkos, G.; Krylov, D. S.; Spree, L.; Zalibera, M.; Ray, R.; Samoylova, N. A.; Chen, C.-H.; Rosenkranz, M.; Schiemenz, S.; Ziegs, F.; Nenkov, K.; Kostanyan, A.; Greber, T.; Wolter, A. U. B.; Richter, M.; Büchner, B.; Avdoshenko, S. M.; Popov, A. A., Air-stable redox-active nanomagnets with lanthanide spins radical-bridged by a metal-metal bond. Nat. Commun. 2019, 10, 571. 4. Liu, F.; Krylov, D. S.; Spree, L.; Avdoshenko, S. M.; Samoylova, N. A.; Rosenkranz, M.; Kostanyan, A.; Greber, T.; Wolter, A. U. B.; Büchner, B.; Popov, A. A., Single molecule magnet with an unpaired electron trapped between two lanthanide ions inside a fullerene. Nat. Commun. 2017, 8, 16098. 5. Chen, C.-H.; Krylov, D. S.; Avdoshenko, S. M.; Liu, F.; Spree, L.; Yadav, R.; Alvertis, A.; Hozoi, L.; Nenkov, K.; Kostanyan, A.; Greber, T.; Wolter, A. U. B.; Popov, A. A., Selective arc-discharge synthesis of Dy2S-clusterfullerenes and their isomer-dependent single molecule magnetism. Chem. Sci. 2017, 8, 6451-6465. 6. Greber, T.; Seitsonen, A. P.; Hemmi, A.; Dreiser, J.; Stania, R.; Matsui, F.; Muntwiler, M.; Popov, A. A.; Westerström, R., Circular dichroism and angular deviation in x-ray absorption spectra of Dy2ScN@C80 single-molecule magnets on h-BN/Rh(111). Phys. Rev. Mater. 2019, 3, 014409. 7. Westerström, R.; Uldry, A.-C.; Stania, R.; Dreiser, J.; Piamonteze, C.; Muntwiler, M.; Matsui, F.; Rusponi, S.; Brune, H.; Yang, S.; Popov, A.; Büchner, B.; Delley, B.; Greber, T., Surface aligned magnetic moments and hysteresis of an endohedral single-molecule magnet on a metal. Phys. Rev. Lett. 2015, 114, 087201. 8. Chen, C. H.; Krylov, D. S.; Avdoshenko, S. M.; Liu, F.; Spree, L.; Westerström, R.; Bulbucan, C.; Studniarek, M.; Dreiser, J.; Wolter, A. U. B.; Büchner, B.; Popov, A. A., Magnetic hysteresis in self-assembled monolayers of Dy-fullerene single molecule magnets on gold. Nanoscale 2018, 10, 11287-11292.