Topological resonance energies of fullerenes and their molecular ions

Abstract

Theoretical argument is presented for the aromaticity of neutral and multiply charged fullerenes ranging from C 20 to C 60. The topological resonance energy method revealed that, in general, larger fullerene molecules are more aromatic. Most fullerenes are highly aromatized when they accept one or more π electrons. Thus, the tendency of buckminsterfullerene anions and some metallofullerenes to retain their spherical π-electron systems can be attributed to the aromatic character of negatively charged fullerene cages. Polyvalent molecular cations of fullerenes are generally unstable. All fullerenes are electron-deficient molecules and are predicted to act as electron acceptors.