Preparation and crystallographic characterization of a new endohedral, Lu₃N@C₈₀ · 5 (o-xylene), and comparison with Sc₃N@C₈₀ · 5 (o-xylene)

The trimetallic nitride template (TNT) approach has been successfully utilized to prepare the new endohedral Lu_sN@C₈₀. Well-ordered crystals of Lu₃N@C₈₀ · 5 (o-xylene) and Sc₃N@C₈₀ · 5 (o-xylene) form upon cooling of oxylene solutions of these endohedrals and they are isomorphous. Although the positions of the fullerene cage (which is fully ordered and located at a crystallographic center of symmetry) and the oxylene molecules are nearly identical in these two structures, the positioning of the metal ions in the two crystals differ in significant ways. However, the expected difference in sizes of lutetium and scandium does not affect the dimensions of the C₈₀ cage. Nevertheless, the positions of the metal atoms do produce a slight outward dislocation of the immediately adjacent carbon atoms.