Cage-like B40C30, B40C40, and B40C50: high-symmetry heterofullerenes isovalent with C-60, C-70, and C-80

摘要

The recent discovery of the cage-like borospherenes B-40(-/0), composed of interwoven double chains of boron, presents the possibility of forming BmCn heterofullerenes as hybrids of borospherenes and carbon fullerenes in dual spaces. Based on extensive first-principles theory calculations, we predict herein the possible existence of the high-symmetry BmCn heterofullerenes S-10 B40C30 (1), C-5 B40C40 (2), and S-10 B40C50 (3), which are isovalent with C-60, C-70, and C-80, respectively. These beautiful borafullerenes with boron aggregations feature one B-30 boron double-chain nanoring at the equator, two bowl-shaped C-15 or C-25 caps at the top and bottom, and ten quasi-planar tetracoordinate peripheral C atoms in ten B-centered B6C hexagonal pyramids that are evenly distributed around the waist in a seamless patched structural motif. Detailed orbital and bonding analyses indicate that, as they are isovalent with C-60, C-70, and C-80, respectively, B40C30 (1), B40C40 (2), and B40C50 (3) possess 30, 35, and 40 bonds, respectively, of which 20 are 5c-2e bonds delocalized over ten hexagonal pyramids that are evenly distributed around the waist. Such structural and bonding patterns confer high stability to these B-C heterofullerenes, which may be synthesized in experiments.