Ring currents and magnetic properties of C 48 N 12 dodecaaza[60-S 6 ]fullerenes

The continuous transformation of the origin of the current density (CTOCD) method has been employed, at the ab initio CHF level of theory and adopting a medium size ad hoc polarized basis set, to predict fairly accurate, origin-independent magnetic properties for the two dodecaaza[60-S6]fullerene isomers. The results show that the two isomers have a very different magnetic behavior, the thermodynamically less stable isomer (I) being characterized by paratropic π-electron ring currents, which largely reduce the overall molecular diamagnetism, and, on the contrary, the more stable isomer (II) characterized by diatropic π-electron ring currents flowing on the external hexagons of each triphenylene-type unit. However, on the basis of the computed magnetizability and central magnetic shielding, II is found to be no more aromatic than fullerene C60. Computed 13C and 15N magnetic shieldings of both isomers are reported, which might be useful for identification purposes.