Long-range magnetic response of toroidal boron structures: B16 and [Co@B16]-/3- species

A correlation between the long-range characteristics of the magnetic response of toroidal boron-based structures is given, involving the uncoordinated B-16 cluster and the hypercoordinated [Co@B-16](-/3-) counterparts. It is found that the perfectly symmetrical doubly aromatic systems share common features, involving a continuous shielding region for the orientation-averaged response (isotropic), and a long-ranged shielding cone under a perpendicularly oriented applied field (Bext z). In contrast, the conflicting aromatic structure given by the slightly distorted species, exhibits an enhanced deshielding cone under B-z(ext), which dominates the isotropic character of the response. In addition, [Mn@B-16](-) and [Cu@B-16](-) clusters were evaluated, denoting the role of the coordinated metal atom in such property. This information is valuable to account for a global magnetic response driven by the bonding pattern acting in each respective compound, and for the possible characterization of intermolecular aggregates or extended structures via NMR experiments.