Assoc. Professor and Reader CONTACT DETAILS:
Address: School of
Chemistry, University of Melbourne, Parkville, VIC, 3010 Australia
Room: 271
Email: evanjb@unimelb.edu.au Teaching responsibilities Field of expertise Spectroscopy of Anion Clusters We use laser spectroscopy to study small negatively charged complexes and clusters in the gas phase. The species consist of an ion core (eg, F-, Cl-, Br-, I-) that is "microsolvated" by one or more neutral molecules (eg, H 2 , C 2 H 2 , NH 3 , or CH 4 ). The goals of the work are to understand how ions are solvated by neutral molecules, and to explore fundamental chemical reaction mechanisms. The strategy used for recording the clusters? infrared spectra is vibrational predissociation spectroscopy. This sensitive approach involves a combination of mass spectrometry and laser spectroscopy. It allows us to record spectra of mass selected clusters, making it possible to trace the evolution of the infrared spectra as the number of solvent units is increased (and the bulk limit is approached).
We have characterised the Cl--(C 2 H 2 ) n clusters in detail. The infrared spectra are appealingly simple, and are consistent with the smaller clusters having structures in which equivalent C 2 H 2 ligands are attached to the central halide anion by linear hydrogen bonds. For clusters containing more than 6-8 acetylene ligands, the first solvation shell is filled and acetylene units begin to occupy the second shell.
Recently we have recorded spectra of the Cl--H 2 , Br--H 2, and I--H 2 complexes. The spectra (shown below) are the the first rotationally resolved spectra of negatively charged complexes, and allow us to precisely describe the interactions between halide anions and H 2 , the simplest molecule.
Spectroscopy of Trapped Nanoparticles
We are currently constructing an electrodynamic trap for containing and probing single charged nanoparticles and aerosols in vacuum. Using the trap, we will be able to suspend a charged particle indefinitely (days or weeks). We intend to use the trap to probe the optical, chemical, and mechanical properties of small metal and semiconductor particles using laser-based techniques.
For further information visit the Bieske group research page
Selected
Publications:
- Weiser PS, Wild DA, Bieske EJ, J. Chem. Phys.,
1999, 110, 9443.
- E.J. Bieske, O. Dopfer, Chem. Rev.
100 (2000) 3963.
- D.A. Wild, P.S. Weiser, E.J. Bieske,
A. Zehnacker, J. Chem. Phys. 115 (2001) 824.
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