Score one for boron. For the first time, a version of the famous football-shaped buckyball has been created from boron.
Discovered in 1985, buckyballs are made from 60 carbon atoms linked together to form hollow spheres. The molecular cages are very stable and can withstand high temperatures and pressures, so researchers have suggested they might store hydrogen at high densities, perhaps making it a viable fuel source. At normal pressures, too much of the lightweight gas can escape from ordinary canisters, and compressing it requires bulky storage tanks.
Boron sits next to carbon in the periodic table, so a boron ball may also display useful properties. But it wasn't clear whether boron could form such structures.
Now Lai-Sheng Wang at Brown University in Providence, Rhode Island, and his colleagues have made a cage-like molecule with 40 boron atoms by vaporising a chunk of boron with a laser then freezing it with helium, creating boron clusters. The team analysed the energy spectra of these clusters and compared them with computer models of 10,000 possible arrangements of boron atoms. The matching configuration revealed they had created the boron ball.
Unlike carbon buckyballs, in which the faces are made of hexagons and pentagons, the boron buckyball is made from triangles, hexagons and heptagons. As a result, it is less spherical but still an enclosed structure. Wang has dubbed the molecule "borospherene". The team is now hunting for a boron analogue of graphene – a strong sheet of carbon just one atom thick that is often touted as a "wonder" material because of its unique electrical properties.
Mark Fox at Durham University, UK likes the name – and is excited at the prospect of finding a boron version of graphene. Buckyballs led to the discovery of graphene, he says, and history may repeat itself with boron.