Buckminster fullerene molecules, the naturally occurring spheres made up of 60 carbon atoms, have long been a darling of the nanotechnology industry. But now, scientists have found a similar structure of boron that could prove equally exciting.
Researchers from Brown, Shanxi and Tsinghua Universities in China have discovered that boron can form a molecular cage made up of 40 atoms. It’s been hypothesised in the past that such a structure could exist, but this is the first experimental evidence to prove it.
While buckyballs are made of 60 carbon atoms arranged in pentagons and hexagons to form a sphere — just like a soccer ball — boron has one less electron than carbon per atom, which means it can’t form the same structure. The researchers spotted earlier this year that boron could form stable, 40-atom structures, but they didn’t know exactly what shape they assumed. So, they modelled over 10,000 possible arrangements, working out the associated electron binding energy for each configuration — a kind of unique molecular fingerprint — -and then set to some practical work.
They then took the samples they knew had formed 40-atom strong structures and used photoelectron spectroscopy to measure their unique fingerprint. Two different structures were found to exist, and they both matched structures modelled by the scientists: one was a semi-flat molecule, the other a buckyball-like spherical cage. The results are published in Nature Chemistry.
The borospherene, as it’s called, isn’t actually quite spherical; n fact it’s a series of 48 triangles, four seven-sided rings and two six-membered rings. Several of the atoms protrude from a theoretical spheres encompassing most of the atoms.
As for applications? It’s a little early to tell. “For us, just to be the first to have observed this, that’s a pretty big deal,” explained Lai-Sheng Wang, a professor of chemistry at Brown to EurekAlert. But he does admit that the next step is to make enough that he can get to testing exactly what they could do in the future. We can’t wait to find out. [Nature Chemistry]