American Chemical Society
ja9069216_si_002.cif (57.68 kB)

Sc3N@(C80-Ih(7))(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?

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posted on 2009-12-09, 00:00 authored by Natalia B. Shustova, Yu-Sheng Chen, Mary A. Mackey, Curtis E. Coumbe, J. Paige Phillips, Steven Stevenson, Alexey A. Popov, Olga V. Boltalina, Steven H. Strauss
The compounds Sc3N@(C80-Ih(7))(CF3)14 (1) and Sc3N@(C80-Ih(7))(CF3)16 (2) were prepared by heating Sc3N@C80-Ih(7) and Ag(CF3CO2) to 350 °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(sp3) atoms. The structures exhibit several unprecedented features for metallic nitride fullerenes, including multiple cage sp3 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 Å for 1 and 0.002 Å for 2), an isolated aromatic C(sp2)6 hexagon on 2, and two negatively charged isolated aromatic C(sp2)5 pentagons on 2 that are bonded to one of the Sc atoms. DFT calculations are in excellent agreement with the two Sc3N conformations observed for 2E(calc) = 0.36 kJ mol−1; ΔE(exp) = 0.26(2) kJ mol−1).