Open-shell fullerene C74: phenalenyl-radical substructures

The π-bond distribution and biradical structure of empty fullerene C74 molecule was shown for the first time by the local symmetry analysis followed by DFT calculation. There are two phenalenyl-radical substructures, which are symmetrically disposed on molecular C3 axis of symmetry. An open-shell electronic structure of fullerene C74 is the main reason of its instability as empty species. A pair of added electrons stabilizes C74 as, for example, in its endohedral metallofullerenes. The probable sites of metal atom(s) inside fullerene C74 are discussed. Possible ways of C74 stabilization are outlined.