Probing the Electronic Structures of Atomic Clusters and Solution Phase Species in the Gas Phase
EMSL Project ID
25392
Abstract
This proposal is a continuation of research under EMSL User Proposal #1391a. Clusters provide intermediate molecular systems bridging the gap between atoms and condensed matter. Their finite and controlled size in principle makes easier for a detailed molecular-level understanding and provides ideal models to address questions in catalysis and solid materials.1 The electronic structure of metal clusters and its evolution with size are important questions in cluster science. A powerful technique to elucidate the electronic structure of metal clusters is photoelectron spectroscopy (PES), in which electron binding energies of a cluster are measured, giving directly the electronic energy levels. The electronic structure, along with the geometrical structures, plays a key role in determining the chemical and physical properties of a cluster. Multiply charged anions (MCAs) are ubiquitous in the condensed phase and constitute an important class of complex anions in the solution phase. Free MCAs have been difficult to study and very few of them are known in the gas phase previously. We have developed an experimental technique combining electrospray ionization (ESI) with PES, which allows us not only to probe free MCAs, but also to access a wide variety of solution phase anions in the gas phase.2,3 Gas-phase solvated clusters have been used as models to obtain insight into the solution phase. The combination of ESI and PES also provides a general and sensitive tool to probe solution phase species and solvated clusters of both simple and complex anions in the gas phase.
We plan to exploit the development made during the past period, including the theoretical collaborations, and propose researches in the following six general areas. 1. Au clusters and other 4d and 5d transition metal clusters. 2. CO- and O2-adsorbed Au clusters: toward a molecular understanding of the CO oxidation by Au nanoparticles. 3. One-dimensional clusters: (MCN)n- (M = Cu, Ag, Au). 4. Singly and multiply charged transition metal cyanide complexes M(CN)xn-, and linear coinage metal cyanide complex clusters (MCN)nCN-. 5. Polynuclear ligated metal clusters, such as Pd6Ru6(CO)242-, Ru11H(CO)273-, Os20(CO)402-, etc. 6. Amino acid-halide anion complexes: searching for gaseous zwitterions.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2007-05-31
End Date
2010-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members