Selective Synthesis, Isolation and Crystallographic Characterization of LaSc2N@Ih-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.
Steven Stevenson, Coralie B. Rose, Juliya S. Maslenikova, Jimmy R. Villareal, Mary A. Mackey, Brandon Q. Mercado, Kelly Chen, Marilyn M. Olmstead, and Alan L. Balch (2012).
Selective Synthesis, Isolation and Crystallographic Characterization of LaSc2N@Ih-C80. Inorganic Chemistry.51, 13096-13102.