PULLMAN, Wash. — A Washington State University scientist has made a discovery that could eventually lead to the development of new materials. The creation of the first all-metal aromatic molecule is reported in the current issue of Science Magazine.
The advance is reported in an article co-authored by Lai-Sheng Wang, physics professor at WSU Tri-Cities and affiliate chief scientist at Pacific Northwest National Laboratory in Richland.
Although aromaticity, a concept invented to account for the unusual stability of certain molecules, previously applied only to organic molecules, Wang’s team has found experimental and theoretical evidence of aromaticity in purely metal molecules.
“We’re expanding the borders of chemistry by building new molecules, called clusters, atom by atom with equipment made specifically for this scientific pursuit,” said Wang. He and several postdoctoral students built a photoelectron spectroscopy system at W.R. Wiley Environmental Molecular Sciences Laboratory, a Department of Energy user lab at PNNL, that measures a molecule’s electronic signature, or energy spectrum.
“We hope to extend this concept to find aromatic molecules in other metals,” Wang said. “We have shown these new molecules can exist as a single unit; now the question is whether we can create new materials from these new molecules.”
Other collaborators on the research are theoretical chemists, assistant professor Alexander Boldyrev and doctoral candidate Aleksey E. Kuznetsov from Utah State University, and technical assistant Xi Li and physics post-doctoral student Hai-Feng Zhang, both from WSU.
The new aromatic molecule was discovered by accident during work on alloy clusters consisting of aluminum and copper. Wang used his photoelectron spectroscopy system to break down metals, cluster them together into new molecules and then measure their electron energy spectra. With these measurements and calculations by Boldyrev, the scientists proved that the new molecules met the structural and electronic criteria for aromatic compounds.
Wang receives funding for his work from the National Science Foundation and the American Chemical Society-Petroleum Research Fund. His recent work has opened a new field of physical chemistry related to solution phase species, multiply charged anions and has been reported in “Nature,” “Chemical and Chemical Engineering News,” “Physical Review Letters,” “Journal of Physical Chemistry” and “Nanotech Alert.”
Educated in the Peoples Republic of China and at the University of California, Berkeley, Wang joined the physics faculty at WSU in 1993. He was named the WSU Westinghouse Distinguished Professor in Materials Science and Engineering and an Alfred P. Sloan Research Fellow in 1997. He received a National Science Foundation Career Award in 1996.