A theoretical survey on the D7d [84]fullerene, a fullerene with two heptagon rings

Our theoretical studies suggest that a novel isomer of [84]fullerenes with D7d point group symmetry is kinetically stable. This novel structure contains two heptagons, 28 hexagons and 14 pentagons. Studying the electronic properties shows that the molecule has a Singlet ground state and the Singlet–Triplet energy gap is about 31.0 kcal mol−1. In addition, the HOMO–LUMO energy gap of the molecule is 2.261 eV, which confirms kinetic stability of the molecule. Studying the magnetizability of the molecule suggests presence of strong diatropic electronic currents, i.e. magnetic aromaticity, in this molecule. Since our newly proposed structure is a high energy fullerene, we suggested a method for synthesis of the molecule based on the application of a template. The Mo2 molecule is suggested as a template for synthesis of the D7d–C84 since complexes containing two 7-membered carbon rings and a Mo2 system have been experimentally prepared before. Observation of such complexes suggests that Mo2 might be able to form metallocenoid complexes with large carbon rings. In addition, it is shown that the Mo2 molecule forms a stable complex with the formed D7d–C84. Bonding properties of the D7d–C84 and its complex with Mo2 were studied within the context of the quantum theory of atoms in molecules, QTAIM.