Abstract

In this work, we systematically explored clusters with formula B7M2- and B8M2 (M = Zn, Cd, Hg). The putative global minima are formed by an M-2 dimer and a disk-shaped boron wheel. Moreover, the chemical bonding analysis revealed that charge transfer from the metal atoms to the boron motifs resulted in (B-7)(3-)(M-2)(2+) and (B-8)(2-)(M-2)(2+) complexes with double (sigma + pi) aromatic boron wheels and a single bond for the metallic dimer. Above all, the computed rotational barriers of the M-M fragment with respect to the boron disk and molecular dynamics simulations indicate a virtually barrierless spin, resembling a magnetic stirrer on a baseplate.