B₁₁₁, B₁₁₂, B₁₁₃, and B₁₁₄: The most stable core-shell borospherenes with an icosahedral B₁₂ core at the center exhibiting superatomic behaviors

Boron allotropes are known to be predominately constructed by icosahedral B₁₂ cages, while icosahedral-B₁₂ stuffing proves to effectively improve the stability of fullerene-like boron nanoclusters in the size range between B₉₈–B₁₀₂. However, the thermodynamically most stable core-shell borospherenes with a B₁₂ icosahedron at the center still remains unknown. Based on the structural motif of D_5h C₇₀ and extensive first-principles theory calculations, we predict herein the high-symmetry C_5v B₁₁₁⁺ (3) which satisfies the Wade's n+1 and n+2 skeletal electron counting rules exactly and the approximately electron sufficient C_s B₁₁₁ (4), C_s B₁₁₂ (5), C_s B₁₁₃ (6), and C_s B₁₁₄ (7) which are the most stable neutral core-shell borospherenes with a B₁₂ icosahedron at the center reported to date in the size range between B₆₈–B₁₃₀, with C_s B₁₁₂ (5) being the thermodynamically most favorite species in the series. Detailed orbital and bonding analyses indicate that these spherically aromatic species all contain a negatively charged icosahedral B₁₂^2– core at the center which exhibits typical superatomic behaviors in the electronic configuration of 1S²1P⁶1D¹⁰1F⁸, with its dangling valences saturated by twelve radial B-B 2c-2e σ bonds between the B₁₂ inner core and the B₇₀ outer shell. The infrared (IR) and Raman spectra of the concerned species are computationally simulated to facilitate their future characterizations.