We study structures and dynamics of building blocks of organometallic networks, supramolecular architectures, and metal nanoclusters. The long-term outcome of our research is a quantitative understanding of how metal centers activate organic molecules and mediate chemical reactions. The research has impact in catalysis, materials synthesis, and environmental and biological technologies.
We use laser vaporization supersonic expansions to produce super-cold molecules, mass spectrometry to measure the mass distribution of reaction products, laser spectroscopy to determine precise ionization energies, metal-ligand bond energies, and electronic-vibrational and, in some cases, rotational energy levels. We use ab initio and conformational sampling methods to narrow the search for new molecules and new spectra and to help interpretation of experimental spectra. The combination of the experimental and theoretical methods determines electronic states and molecular structures.
Current research projects include (1) transition metal-aromatic hydrocarbons, (2) metal-heterocycles, (3) metal-DNA/RNA bases, and (4) metal atomic clusters, and (5) metal oxide, carbide and nitride clusters.
The most significant results from our research activities are the successful applications of pulsed field ionization-zero electron kinetic energy (ZEKE), mass analyzed threshold ionization (MATI), and IR-UV resonant two-photon ionization spectroscopy to metal clusters and complexes. These techniques not only offer high spectral resolution, but also provide the ability to study molecular systems more akin to condensed-phase inorganic and organometallic chemistry. The field is wide open, and we are well positioned as a major player. For the first time, we are able to do gas-phase laser electronic-vibrational spectroscopy in a systematic way that varies the ligands or metal elements, much as our synthetic colleagues do inorganic reactions.