B 111 , B 112 , B 113 , and B 114 : The most stable core-shell borospherenes with an icosahedral B 12 core at the center exhibiting superatomic behaviors

Boron allotropes are known to be predominately constructed by icosahedral B 12 cages, while icosahedral-B 12 stuffing proves to effectively improve the stability of fullerene-like boron nanoclusters in the size range between B 98 –B 102 . However, the thermodynamically most stable core-shell borospherenes with a B 12 icosahedron at the center still remains unknown. Based on the structural motif of D 5 h C 70 and extensive first-principles theory calculations, we predict herein the high-symmetry C 5 v B 111 + ( 3 ) which satisfies the Wade’s n +1 and n +2 skeletal electron counting rules exactly and the approximately electron sufficient C s B 111 ( 4 ), C s B 112 ( 5 ), C s B 113 ( 6 ), and C s B 114 ( 7 ) which are the most stable neutral core-shell borospherenes with a B 12 icosahedron at the center reported to date in the size range between B 68 –B 130 , with C s B 112 ( 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 B 12 2− core at the center which exhibits typical superatomic behaviors in the electronic configuration of 1S 2 1P 6 1D 10 1F 8 , with its dangling valences saturated by twelve radial B-B 2c-2e σ bonds between the B 12 inner core and the B 70 outer shell. The infrared (IR) and Raman spectra of the concerned species are computationally simulated to facilitate their future characterizations.