Chemists have observed a boron buckminsterfullerene for the first time, providing experimental evidence for an 80-atom cage whose existence has been debated since 2007 (Chem. Sci. 2026, DOI: 10.1039/d6sc02674e).
Buckminsterfullerenes, or buckyballs, are hollow, soccer ball–shaped molecular cages first discovered in carbon. Their discovery launched a new branch of nanoscience. Boron, carbon’s electron-deficient neighbor in the periodic table, has long been considered a candidate for its own fullerene.
"Boron is known as the rule breaker in chemistry," says Lai-Sheng Wang of Brown University, who led the experimental work. "For 80 atoms to exhibit this structure—I still find it incredible."
First author Hyun Choi produced the boron clusters by vaporizing a boron target with laser light. Argon was mixed into the helium carrier gas to cool and stabilize the clusters. Proper cooling enables B80 to settle into a single structure. The process yielded a photoelectron spectrum—an electronic fingerprint of a material—with three sharp peaks matching the fullerene structure. "The moment I saw the spectrum, I knew I was looking at something remarkable," Choi says.
"I’d congratulate the authors with finding the ball at last," says Boris Yakobson a materials scientist at Rice University who first predicted the boron cage’s stability. “But I’d also wish to see more independent confirmations coming from other labs since it is such an unbelievable structure,” he exclaims!
The finding puts the experiment in direct conflict with a large body of computational work. Density functional theory (DFT), the field’s workhorse method, ranks the buckyball geometry well below other B80 structures in terms of predicted stability.
To strengthen their conclusions, the researchers simulated spectra for every competing structure. Only the buckyball matched. “DFT is wrong for this particular system,” Wang says. “This challenges DFT methods.” Not everyone agrees the discrepancy is as significant as it appears. Yakobson argues that the energy gap is far less dramatic when considered on a per-atom basis.
Wang’s group observed a boron cage of 40 atoms in 2014. Although cage-shaped, B40 does not have the soccer ball symmetry of C60, the carbon buckminsterfullerene composed of 60 carbon atoms. “B80 is exactly equivalent to C60,” Wang says.
B80 is valence-isoelectronic with C60—meaning both have 240 valence electrons and nearly identical bonding. With its slightly larger diameter and stronger electron affinity, B80 may be a better electron acceptor. Wang speculates that bulk B80 could serve as a semiconductor, a hydrogen storage material, or—if doped—a superconductor. But none of this is possible without bulk synthesis, which has not yet been achieved. Synthesis is complicated by boron’s poor conductivity and two naturally occurring isotopes.
Wang’s group aims to test B80’s reactivity with molecules such as water and oxygen. If the boron-boron bonds survive, Wang says, bulk synthesis may be within reach. The team also wants to probe larger boron clusters to determine if the cage structure persists and where it might break down.
Wang is optimistic about synthesis. When his group proposed borophene, a 2D boron analog of graphene, two independent teams synthesized it within 2 years. "Once you show something is possible, people will try it," Wang says.