Sea-shell-like B and B: two new axially chiral members of the borospherene family.

Since the discovery of the cage-like borospherenes B and the first axially chiral borospherenes / B , a series of fullerene-like boron clusters in different charge states have been reported in theory. Based on extensive global minimum searches and first-principles theory calculations, we present herein two new axially chiral members B (I) and B (VI) to the borospherene family. B (I) features two equivalent heptagons on the top and one octagon at the bottom on the cage surface, while B (VI) possesses two equivalent heptagons on top and two equivalent heptagons at the bottom. Detailed bonding analyses show that both sea-shell-like B (I) and B (VI) follow the universal σ + π double delocalization bonding pattern of the borospherene family, with ten delocalized π bonds over a σ skeleton, rendering spherical aromaticity to the systems. Extensive molecular dynamics simulations show that these novel borospherenes are kinetically stable below 1000 K. The IR, Raman, and UV-vis spectra of B (I) and B (VI) are computationally simulated to facilitate their future experimental characterizations.