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.