Christine M. Thomas

WHAT DID THE 2010 EARLY CAREER AWARD ALLOW YOU TO DO?

In order to more sustainably meet the global energy demands of the future, a drastic shift in the world’s energy production strategy is required to replace or, more efficiently use, fossil fuels. 

One possible strategy is the storage of energy in chemical bonds by using solar-derived energy to convert abundant natural resources such as water, carbon dioxide, and dinitrogen into clean value-added fuels. This strategy entails the design of catalysts that can facilitate the novel chemical transformations necessary to convert small molecules into useful fuels in an energy-efficient and environmentally benign manner. The underlying challenges behind the activation of small molecules lie in the multi-electron redox processes involved and the inherent strength of the bonds in these molecules. Furthermore, most of the successful catalysts designed to date entail the use of precious metals (e.g. platinum, palladium, rhodium, etc.) that are both expensive and in short supply.

This Early Career Award made it possible to begin to tackle these challenges through the study of the fundamental aspects of catalyst design to ultimately access small molecule activation processes under mild conditions without the use of precious metals. A novel bimetallic strategy was developed, specifically involving the linkage of an electron-deficient early transition metal and a more electron-rich late transition metal.  The interactions between the two very different metals in these species were shown to facilitate multi-electron redox transformations, as well as the activation of typically unreactive small molecule substrates such as carbon dioxide.

ABOUT:

Christine M. Thomas is the Fox Professor of Chemistry in the Department of Chemistry and Biochemistry at The Ohio State University and formerly a professor in the Department of Chemistry at Brandeis University.

SUPPORTING THE DOE SC MISSION:

The Early Career Award program provides financial support that is foundational to young scientists, freeing them to focus on executing their research goals. The development of outstanding scientists early in their careers is of paramount importance to the Department of Energy Office of Science. By investing in the next generation of researchers, the Office of Science champions lifelong careers in discovery science. 

For more information, please go to Early Career Research Program page.

THE 2010 PROJECT ABSTRACT:  

Early‐Late Heterobimetallic Complexes Linked by Phosphinoamide Ligands: Tuning Redox Potentials & Small Molecule Activation

The goal of this project is to increase our understanding of how interactions between early and late transition metals can be used as a strategy to control chemical transformations related to the clean production of fuels. Energy‐efficient conversion of abundant small molecules such as CO₂ and H₂O into liquid fuels is both scientifically challenging and strategically important for society. Hetero‐bimetallic complexes (of, for example, Co and Zr) where one metal is strongly acidic and the other strongly basic possess polar bonds and unusual reactivities. Such bimetallic interaction can be tuned and stabilized by means of phophino‐amide ligands. Using complexes designed and synthesized at the molecular level, this project will generate a better understanding of structure‐activity relations and will lead to catalysts for low‐temperature activation of CO₂, O₂, H₂, and N₂ and their conversion into liquid fuel precursors.

RESOURCES:

J.P. Krogman, B.M. Foxman, and C.M. Thomas, “Activation of CO₂ by a heterobimetallic Zr/Co complex.” J. Am. Chem. Soc. 133, 14582 (2011). [DOI: abs/10.1021/ja2071847]

S.L. Marquard, M.W. Bezpalko, B.M. Foxman, and C.M. Thomas, “Stoichiometric C=O bond oxidative addition of benzophenone by a discrete radical intermediate to form a cobalt(I) carbene.” J. Am. Chem. Soc. 135, 6018 (2013). [DOI: 10.1021/ja4022683]

S. Kuppuswamy, T.M. Powers, J.P. Krogman, M.W. Bezpalko, B.M. Foxman, and C.M. Thomas, “Vanadium-iron complexes featuring metal-metal multiple bonds.” Chem. Sci. 4, 3557 (2013). [DOI: 10.1039/C3SC51337H]

Additional profiles of the 2010 Early Career Award winners can be found at:  https://www.energy.gov/science/listings/early-career-program.   

The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit www.energy.gov/science.

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