Metalloborospherenes with a Stabilized Classical Fullerene-like Borospherene B Act as Nonlinear Optical Switches, Electron Reservoirs, Molecular Capacitors, and Molecular Reactors.

Using a new method of η-Li and η-Mg atoms capping the faces of the classical fullerene-like borospherene B, we theoretically predict an exohedral metalloborospherene MgLi&B molecule. Remarkably, a newfangled endoexo cage isomerism is proposed. Further, embedding Mg atoms in the B cage forms endohedral derivatives. Due to the intramolecular pull-push electron transfer relay, these obtained molecules possess unequal multilayered and alternant spherical charge distribution. The outer is an excess electron layer, bringing a molecular nonlinear switch character and an electron reservoir behavior with strong electron-donating and -accepting abilities. The middle (Mg)(Li) and the outer layers together constitute an electric double layer, presenting the behavior of a molecular capacitor where the electronic charge-discharge process occurs in the outer excess electron layer. The inner part is an empty cage B with a strong negative electric field. The valence electrons of the embedded Mg atoms are transformed into new excess electrons and added in the outer excess electron layer, also exhibiting the charging behavior of the molecular capacitor. Considering the chemical reaction in the inner cage, the embedded Mg atom is ionized, forming an Mg cation and 2e under the strong negative electric field; meanwhile, 2e is powerfully pushed into the outer excess electron layer. This chemical process shows a generalized Coulomb explosion, and thus the exohedral metalloborospherene molecules with cage B may act as molecular reactors. The new species mark the genesis of classical fullerene-like borospherene chemistry and stimulate their applications in molecular nonlinear optical and nanoelectronics.