Sc3N@(C80-Ih7)(CF3)14 and Sc3N@(C80-Ih(7))(CF3)16. Endohedral metallofullerene derivatives with exohedral addends on four and eight triple-hexagon junctions. Does the Sc3N cluster control the addition pattern or vice versa?

The compounds Sc(3)N@(C(80)-I(h)(7))(CF(3))(14) (1) and Sc(3)N@(C(80)-I(h)(7))(CF(3))(16) (2) were prepared by heating Sc(3)N@C(80)-I(h)(7) and Ag(CF(3)CO(2)) to 350 degrees C in a sealed tube. The structures of 1 and 2 were determined by single-crystal X-ray diffraction. They are the first X-ray structures of any endohedral metallofullerene with more than four cage C(sp(3)) atoms. The structures exhibit several unprecedented features for metallic nitride fullerenes, including multiple cage sp(3) triple-hexagon junctions (four on 1 and eight on 2), no cage disorder and little (2) or no (1) endohedral atom disorder, high-precision (C-C esd's are 0.005 A for 1 and 0.002 A for 2), an isolated aromatic C(sp(2))(6) hexagon on 2, and two negatively charged isolated aromatic C(sp(2))(5)(-) pentagons on 2 that are bonded to one of the Sc atoms. DFT calculations are in excellent agreement with the two Sc(3)N conformations observed for 2 (DeltaE(calc) = 0.36 kJ mol(-1); DeltaE(exp) = 0.26(2) kJ mol(-1)).