Observation of an all-boron fullerene

Main-group analogues to fullerene-C60 have been predicted theoretically many times. Now, B40− has been observed using photoelectron spectroscopy and, with its neutral analogue, B40, confirmed computationally. In contrast to fullerene-C60, the all-boron fullerene (or borospherene) features triangles, hexagons and heptagons, bonded uniformly by delocalized σ and π bonds over the cage surface.