Selective Synthesis, Isolation, and Crystallographic Characterization of LaSc₂N@<i>I</i>_<i>h</i>‑C₈₀

The successful preparation and isolation of the mixed-metal endohedral fullerene, LaSc2N@Ih-C80, and its structural characterization by single-crystal X-ray diffraction are reported. Results from chemically adjusting plasma temperature, energy, and reactivity (CAPTEAR) experiments indicate that a 10 wt % addition of Cu­(NO3)2·2.5H2O to a mixture of La2O3 and Sc2O3 decreases the amount of C60 and C70 found in soot extracts by an order of magnitude. By combining a stoichiometric 2-fold excess of La to Sc atoms in the plasma reactor, an extract containing a greater abundance of LaSc2N@Ih-C80 relative to Sc3N@Ih-C80 was obtained. Alternatively, the stir and filter approach (SAFA method) can be used to remove the empty cage fullerenes from a carbon soot sample prepared without using Cu­(NO3)2·2.5H2O. LaSc2N@Ih-C80 has been characterized by UV/vis absorption spectroscopy and by single-crystal X-ray diffraction. Ordered crystals with nearly identical orientations of the endohedral relative to the porphyrin have been obtained by cocrystallization of LaSc2N@Ih-C80 with either NiII(OEP) or H2(OEP). The LaSc2N unit is planar, although earlier computations suggested that it would be pyramidal.