Ih symmetrical (4,6)-fullerenes and their local ring aromaticity: A first principle study

Abstract

As the natural extension of carbon fullerene, a series of Ih symmetrical (4,6)-fullerenes were constructed and investigated using first principle methods. These Ih (4,6)-fullerenes consist of many four- and six-membered rings and are classified into two types: (1) those with isolated four- and six-membered rings and (2) those with connected four- and/or six-membered rings. Though these (4,6)-fullerenes are less stable than Ih C60 and C240 (5,6)-fullerene, it is possible to synthesize them from their elemental unit, antikekulene, which was nearly synthesized experimentally. Though the (4,6)-fullerenes are mainly spherical and antiaromatic compounds, the local aromatic indexes indicate that all of the planar π-conjugated rings have local aromaticity in fullerenes, which provides reasonable delocalization, which is consistent with our chemical intuition. Because of the huge cavities and suitable pore sizes present in the (4,6)-fullerenes, they can be taken as potential nanocontainers for the storage of small molecules.