Stabilities Referring to the f Electron Effect in Erbium-Based Endohedral Metallofullerenes: Revisiting Er 2 @C 80 and the Missing Er 2 C 2 @C 78

作者：Yanbo Han, Hong Zheng, Jun He, Mengyang Li, Masahiro Ehara, Xiang Zhao · 发表于：Inorganic Chemistry · 年份：2025 · DOI：10.1021/acs.inorgchem.5c00661 · 被引用次数：5 · 研究领域：Fullerene Chemistry and Applications、Graphene research and applications、Boron and Carbon Nanomaterials Research

Endohedral metallofullerenes (EMFs) involving lanthanide elements exhibit unique physicochemical properties, with one of the key factors being the presence of 4f electrons. These 4f electrons contribute to complex metal–metal and metal–cage interactions. Despite extensive research on their properties, a thorough theoretical interpretation of the effect of 4f electrons on the EMF stability and structure remains lacking. In this study, building on previous findings that highlighted Er 2 @C 80 as a potential magnetic molecule, the stabilities and metal–metal/metal–cage interactions of the Er 2 C 80 system have been explored using density functional theory calculations combined with statistical thermodynamic analyses. Three thermodynamically stable isomers are identified: Er 2 @ I h (31924)-C 80, Er 2 C 2 @ C 1 (23349)-C 78, and Er 2 C 2 @ C 1 (22595)-C 78 . The Er 2 @ I h -C 80 isomer features a two-center one-electron Er–Er bond stabilized by significant charge transfer to the C 80 cage. Extended Transition State–Natural Orbitals for Chemical Valence (ETS–NOCV) analysis reveals electron redistribution within the cage and stabilization of the Er–Er bond, which corroborates earlier model conclusion of the magnetic properties of Er 2 @C 80 . Analyses of different electronic configurations of the main Er 2 C 80 isomers and Er 2 cluster reveal a significant impact on the exchange interaction of 4f electrons to the stability of the whole Er 2 C 80 molecule.