A single crystal X-ray diffraction study of a fully ordered cocrystal of pristine Sc3N@D3h(5)–C78

Black crystals of Sc3N@D3h(5)–C78·NiII(OEP)·2(benzene) contain a fully ordered endohedral fullerene cage and fully ordered contents. Thus, the X-ray crystallographic study allows detailed examination of its structural properties. The planar Sc3N group lies perpendicular to the threefold axis of the fullerene cage with the scandium ions bound to the three 6:6 ring junctions that lie in the horizontal mirror plane of the molecule. The Sc–N distances are 2.0111(10), 2.0106(10), and 1.9998(10) Å and the shortest Sc–C distances fall in the range 2.2371(13)–2.2591(13) Å. Those six carbon atoms nearest the scandium ions are the most pyramidalized carbon atoms in the molecule with an average θp = 13.9° compared to θp = 11.6° for C60 and to average θp = 11.3° for the 12 carbon atoms along the C3 axis at the poles of the molecule. The C–C bond distances at the 6:6 and 5:6 ring junctions do not show the distinct variations that are found in C60. The shortest average C–C bond length, 1.391(2) Å, and the longest average bond length, 1.466(1) Å, occur at 6:6 ring junctions.

The X-ray crystallographic study of Sc3N@D3h(5)–C78·NiII(OEP)·2(benzene) allows detailed examination of the structural properties of the endohedral fullerene, Sc3N@D3h(5)–C78, which is fully ordered in this crystal.Figure optionsDownload as PowerPoint slide