Probing the Electronic Structure of Metal Clusters
EMSL Project ID
1391a
Abstract
Photoelectron spectroscopy is used to probe the electronic structure of size-selected atomic clusters produced using laser vaporization. In this proposal, we will focus on our studies on small boron, gold clusters, as well alloy clusters consisting of more one type of atoms. One of the most interesting features of elemental boron and many bimetallic boron compounds is the occurrence of highly symmetric icosahedral clusters. The rich chemistry of boron is also dominated by three-dimensional cage structures. Despite its proximity to carbon in the periodic table, elemental boron clusters have been scarcely studied experimentally. We have engaged in an extensive investigation of small boron clusters using photoelectron spectroscopy and ab initio calculations. I have found experimental and theoretical evidence that small boron clusters prefer planar structures and exhibit aromaticity and antiaromaticity according to the Hückel rules, akin to planar hydrocarbons. Aromatic boron clusters possess more circular shapes whereas antiaromatic boron clusters are elongated, analogous to structural distortions of antiaromatic hydrocarbons. Small gold cluster anions have also been shown to assume planar structures up to Au12-. I have used joint photoelectron spectroscopic and theoretical efforts to confirm the planarity of small gold cluster anions and discovered a tetrahedral Au20, which can be viewed as the fusion of four planar triangular Au10 clusters. We will extend our work on born and gold clusters, as well as mixed cluster involving these two elements.
Project Details
Project type
Exploratory Research
Start Date
2004-12-20
End Date
2007-06-04
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members