ScY@C_3v(8)‐C₈₂:Metal‐Metalσ²Bond in MixedRare‐EarthDi‐metallofullerenes^†

Comprehensive SummaryThe experimental investigation of rare‐earth metal‐metal bonds remains a challenge in the study of chemical bonds. Herein, we report the synthesis and characterization of a novel heteronuclear di‐metallofullerene, ScY@C3v(8)‐C82, which contains a mixed rare‐earth metal‐metal bond. ScY@C3v(8)‐C82was successfully synthesized by arc‐discharging method and characterized by mass spectrometry, UV‐vis‐NIR spectroscopy and single‐crystal X‐ray diffraction crystallography, which unambiguously determined its molecular structure. Theoretical calculations were also performed to study the optimized positions of Sc‐Y metallic dimer and the electronic configuration. The combined experimental and theoretical results confirmed that both Sc and Y atoms transfer two electrons to theC3v(8)‐C82cage,i.e., (ScY)4+@(C3v(8)‐C82)4–. In particular, a covalent Sc‐Y σ2bond, which has never been reported before, is proven to be formed insideC3v(8)‐C82fullerene cage. This work presents a novel di‐metallofullerene containing mixed rare‐earth metal‐metal bond and expands the understanding of metal‐metal bonding of rare earth elements.