Probing the Electronic Structures of Transition Metal Clusters and Solution Anions Using Photoelectron Spectroscopy and Photoelectron Imaging

Brown University, Providence RI

Investigators

Abstract

In this project funded by the Chemical Structure, Dynamics and Mechanisms Program of the Division of Chemistry, Professor Lai-Sheng Wang of Brown University, together with his graduate and undergraduate student researchers, will study the structures of large gold clusters and how properties of gold clusters can be modified by dopant atoms. These clusters will be produced by laser vaporization and will be investigated through a combination of mass spectrometry and photoelectron spectroscopy aided by theoretical calculations. The ultimate goal of this research is to understanding the mechanisms of new catalytic properties discovered for gold nanoparticles. Toward this end, the Wang group will also study CO and O2 adsorbed on gold clusters, which will contribute to a molecular-level understanding of CO oxidation by gold nanoparticles. Another research direction pursued under the support of this program is to study solution phase molecules in the gas phase using electrospray ionization and photoelectron spectroscopy, a unique experimental technique developed in the Wang group. They will focus on the investigation of Au-ligand complexes, aimed at a better understanding of the chemical bonding properties of the gold atom. It has been found in prior research supported under this program that a gold atom can behave like a hydrogen atom in certain Au-containing clusters. The Wang group is interested in probing further the covalent bonding characters of Au with various chemical ligands. Gold complexes have increasingly been found to catalyze important organic transformations in solution. A deeper understanding of the chemical bonding properties of the gold atom can provide insight into the intermediates and mechanisms of homogeneous catalysis by gold complexes. Gold nanoparticles have a wide range of applications in catalysis, molecular electronics and biology. Careful studies like those of Prof. Wang and his group build a knowledge base of the electronic and chemical properties of these species which help to inform the various nanotechnology areas where these substances play a role. The students receiving research training in Prof. Wang's research group will learn to use sophisticated equipment in a unique university/national laboratory environment. Prof. Wang's gold cluster research has captured the public interest, and Prof. Wang continues to be an excellent ambassador for science.