<p>The analysis of previously experimentally obtained and characterized by X-ray perfluoralkyl derivatives C<sub>74</sub>(D<sub>3h</sub>)(CF<sub>3</sub>)<sub>12</sub> and C<sub>76</sub>(T<sub>d</sub>)(CF<sub>3</sub>)<sub>12</sub> have shown for the first time that the most feasible positions of addends are phenalenyl-radical substructures and/or hexagons with delocalized pi-bonds, that lead to stabilization of these molecules. The most probable addition positions of H<sup>•</sup> and CF<sub>3</sub><sup>•</sup> radicals to the «missing» fullerenes С<sub>74</sub> (D<sub>3h</sub>) and С<sub>76</sub> (T<sub>d</sub>) are revealed on the basis of developed approach of molecular modeling followed by DFT calculations. Radical addition reactions seem to be useful for stabilization of open-shell fullerenes.</p
