Dimerization of Endohedral Fullerene in a Superatomic Crystal

We describe a solid state material created from the reaction of Ni₉ Te₆ (PEt₃ )₈ and Lu₃ N@C₈₀ . The resulting superatomic crystal, [Ni₁₂ Te₁₂ (PEt₃ )₈ ]₂ [(Lu₃ N@C₈₀ )₂ ], contains dimers of Lu₃ N@C₈₀ that form upon reduction of the fullerene through a single C-C bond at the triple hexagon junctions. The encapsulated Lu₃ N cluster displays an unprecedented orientation that is collinear and coplanar with the intercage carbon bond. Density functional theory calculations rationalize this unique bonding and relative orientation of the Lu₃ N clusters. Our structural and theoretical results provide new insights into the effect that the M₃ N cluster species has on the dimerization process of endohedral fullerenes.