Paramagnetic states of metals and 13C in isolated endohedral fullerenes

The encapsulated metal ions inside closed carbon cages gives rise to a wide range of novel molecules and materials. Endohedral metallofullerenes were prepared in macroscopic quantities and successfully characterized. The aim of this contribution is to study scandium, yttrium and lanthanum containing fullerenes with respect to their electronic state especially in solution at high purity. Sc@C82, Y@C82 and La@C82 having the metal redox state of M3+ ESR hyperfine structures were caused by the nuclear spin of the metal ion. The hyperfine structure in the ESR spectra of isolated metallofullerenes shows well resolved 13C satellite in Sc@C82, Y@C82 and La@C82. It is concluded that under the described conditions there exist five groups of C atoms in the C82 cage similar in the electronic state. The electronic structure of these endohedral fullerenes is studied by the LCAO-DFT quantum chemical procedure.