2026 Chupka Lecture: Boron Nanoclusters

Please join Yale Chemistry for the 2026 William A. Chupka Lecture in physical and theoretical chemistry with Prof. Lai-Sheng Wang, Jesse H. and Louisa D. Sharpe Metcalf Professor of Chemistry, Brown University. Summary: The study of carbon clusters led to the discoveries of fullerenes, carbon nanotubes, and graphene. Are there other elements that can form similar nanostructures? With this question in mind, we have been investigating the size-dependent structures and chemical bonding of boron nanoclusters using photoelectron spectroscopy over the past two decades. We have found that elemental boron clusters possess planar structures, in contrast to bulk boron, which is dominated by three-dimensional polyhedral building blocks. The discovery of planar boron clusters laid the foundation for 2D boron nanomaterials. In particular, the observation of the planar B36 cluster with a central hexagonal vacancy provided the first experimental evidence that atomically thin boron sheets with hexagonal vacancies, known as borophenes, are viable. Borophene has since been synthesized and characterized on inert substrates, forming a new class of synthetic 2D materials. The B40 cluster was first found to be an all-boron fullerene, possessing D2d symmetry and a cage diameter slightly smaller than that of C60. Very recently, we obtained compelling experimental evidence for boron buckminsterfullerene, an 80-atom boron cluster with the same soccer-ball shape as C60, but with the twenty hexagons filled. In this talk, I will take you through our journey in studying boron clusters, leading up to the discovery of boron fullerenes. Bio: Lai-Sheng Wang is an experimental physical chemist interested in the study of nanoclusters and solution-phase chemistry in the gas phase. He received his B.S. degree in Chemistry from Wuhan University in 1982 and his Ph.D. in Chemistry from the University of California at Berkeley in 1990. After a postdoctoral stay at Rice University, he took a joint position between Washington State University and Pacific Northwest National Laboratory in 1993, then accepted an appointment at Brown in 2009. Dr. Wang's research focuses on the investigation of the fundamental behaviors of nanoclusters using photoelectron spectroscopy and computational techniques. Research in his group has led to the discovery of golden buckyballs and the smallest golden pyramid, as well as aromatic clusters and planar boron clusters. Dr. Wang's group has also pioneered spectroscopic studies in the gas-phase of free multiply-charged anions and complex solution-phase anions, such as metal complexes, redox species, and biologically-relevant molecules. For more information on Dr. Wang's research: Research – LS Wang Group Hosted by Prof. Mark Johnson.