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.^1-3 Besides, EMF-SMMs can form monolayers by sublimation,⁴ self-assembly from solution,^{5, 6} or electrospray deposition,⁷ and such monolayers retain their SMM properties on conducting 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 (9), 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 (10), 2981-2993.
3. Wang, Y.; Velkos, G.; Israel, N. J.; Rosenkranz, M.; Büchner, B.; Liu, F.; Popov, A. A., Electrophilic Trifluoromethylation of Dimetallofullerene Anions en Route to Air-Stable Single-Molecule Magnets with High Blocking Temperature of Magnetization. J. Am. Chem. Soc. 2021, 143 (43), 18139–18149.
4. Krylov, D. S.; Schimmel, S.; Dubrovin, V.; Liu, F.; Nguyen, T. T. N.; Spree, L.; Chen, C.-H.; Velkos, G.; Bulbucan, C.; Westerström, R.; Studniarek, M.; Dreiser, J.; Hess, C.; Büchner, B.; Avdoshenko, S. M.; Popov, A. A., Substrate-independent magnetic bistability in monolayers of single molecule magnet Dy₂ScN@C₈₀ on metals and insulator. Angew. Chem. Int. Ed. 2020, 59 (14), 5756-5764.
5. Chen, C.-H.; Spree, L.; Koutsouflakis, E.; Krylov, D. S.; Liu, F.; Brandenburg, A.; Velkos, G.; Schimmel, S.; Avdoshenko, S. M.; Fedorov, A.; Weschke, E.; Choueikani, F.; Ohresser, P.; Dreiser, J.; Büchner, B.; Popov, A. A., Magnetic Hysteresis at 10 K in Single Molecule Magnet Self-Assembled on Gold. Adv. Sci. 2021, 8 (5), 2000777.
6. Spree, L.; Liu, F.; Neu, V.; Rosenkranz, M.; Velkos, G.; Wang, Y.; Schiemenz, S.; Dreiser, J.; Gargiani, P.; Valvidares, M.; Chen, C.-H.; Büchner, B.; Avdoshenko, S. M.; Popov, A. A., Robust Single Molecule Magnet Monolayers on Graphene and Graphite with Magnetic Hysteresis up to 28 K. Adv. Funct. Mater. 2021, 31, 2105516.
7. Paschke, F.; Birk, T.; Enenkel, V.; Liu, F.; Romankov, V.; Dreiser, J.; Popov, A. A.; Fonin, M., Exceptionally High Blocking Temperature of 17 K in a Surface-Supported Molecular Magnet. Adv. Mater. 2021, 33 (40), 2102844.