The structure of fullerene C66, which does not obey the rule of isolated pentagons, and endohedral metallofullerene Sc2@C66: Quantum-chemical calculations

The molecular structure of the isomer 4348 (C 2v ) of fullerene C66, which does not obey the rule of isolated pentagons, is analyzed. Data on the distribution of single, double, and delocalized bonds in this molecule were obtained for the first time. Quantum-chemical (DFT) calculations showed that the hypothetical C66 molecule was a biradical, which was the reason for its instability. In metallofullerene Sc2@C66, the main changes in bond lengths and electron density transfer from scandium atoms to the carbon shell of fullerene occurred in pentalene substructures and conjugated π bond chains.