David Jenkins

Assistant Professor
Inorganic Chemistry

Magnetic materials, organometallic chemistry, catalysis.

B.A., Cornell University (2000)
Ph.D., California Institute of Technology (2005)

NSF Graduate Fellow
Miller Instistute for Basic Research in Science Postdoctoral Fellow

Research

My group's research focuses on synthesis, both inorganic and organic, to develop chemical systems ranging from catalysis to magnetic materials. To characterize the broad spectrum of materials that we synthesize, we apply a wide variety of analytical techniques including nuclear magnetic resonance, magnetometry, mass spectrometry, and X-ray crystallography. We concentrate on two distinct areas of research, multi-functional magnetic materials and organometallic chemistry featuring catalysis, group-transfer reactions, and small molecule activation.

Magnetic materials. Spin-crossover complexes undergo a spin change (a change in the net number of unpaired electrons) as a function of external forces such as changes in temperature or pressure. These changes in the magnetic moment make these materials viable for use in data storage devices. My group is interested in expanding spin-crossover effects to metal-organic frameworks. Metal-organic frameworks (MOFs) are crystalline compounds consisting of metal atoms coordinated to rigid organic linkers to form charge neutral one- , two- , or three-dimensional structures that are typically porous. By combining the properties of these two classes of materials, we can develop multi functional materials for molecular sensing, gas separation, and data storage. In particular, we are interested in metal-organic frameworks featuring iron, since iron(II) complexes have been demonstrated to undergo spin-crossover with a wide variety of nitrogenous ligands. Testing new organic linkers in these systems allows us to investigate the properties of these materials and evaluate their potential as multi functional magnetic materials.

Catalysis, group transfer and small molecule activation. My group is developing macrocyclic carbene ligands, which are structurally similar to porphyrins, as supports for metal ions in a variety of roles ranging from catalysis and group-transfer to small molecule activation. Our emphasis is on the exploration of low-valent transition metal complexes incorporating these macrocycles as the supporting ligand. Our catalytic and group transfer projects include oxidation reactions with dioxygen and aziridination reactions with organic azides. We are also interested in the preparation of novel low-valent metal-ligand multiple-bonds. In addition, we are investigating the synthesis of larger macrocycles that will allow multiple metal ions to work in concert during a catalytic process.

Representative publications

A Redox-Switchable Single-Molecule Magnet Incorporating [Re(CN)₇]^3-. Freedman, Danna E.; Jenkins, David M.; Iavarone, Anthony T.; Long, Jeffrey R. J. Am. Chem. Soc. 2008, 130, 2884-2885.

Vibrational Spectroscopy and Analysis of Pseudo-tetrahedral Complexes with Metal Imido Bonds. Mehn, Mark P.; Brown, Steven D.; Jenkins, David M.; Peters, Jonas C.; Que, Lawrence, Jr. Inorg. Chem. 2006, 45, 7417-7427.

Spin State Tuning at Pseudotetrahedral d⁷ Ions: Examining the Structural and Magnetic Phenomena of Four Coordinate [BP₃]Co^II-X Systems. Jenkins, David M.; Peters, Jonas C. J. Am. Chem. Soc. 2005, 127, 7148-7165.

Solution and Solid-State Spin-Crossover Behavior in a Pseudotetrahedral d⁷ Ion. Jenkins, David M.; Peters, Jonas C. J. Am. Chem. Soc. 2003, 125, 11162-11163.

Elucidation of a Low Spin Cobalt(II) System in a Distorted Tetrahedral Geometry. Jenkins, David M.; Di Bilio, Angel J.; Allen, Matthew J.; Betley, Theodore A.; Peters, Jonas C. J. Am. Chem. Soc. 2002, 124, 15336-15350.

Oxidative Group Transfer to Co(I) Affords a Terminal Co(III) Imido Complex. Jenkins, David M.; Betley, Theodore A.; Peters, Jonas C. J. Am. Chem. Soc. 2002, 124, 11238-11239.

Redox Induced Reversible Structural Transformations of Dimeric and Polymeric Phenanthroline-Based Copper Chelates. Bernhard, Stefan; Takada, Kazutake; Jenkins, David; Abruña, Héctor D. Inorg. Chem. 2002, 41, 765-772.

A Homoleptic Phosphine Adduct of Tl(I). Shapiro, Ian R.; Jenkins, David M.; Thomas, J. Christopher; Day, Michael W.; Peters, Jonas C. Chem. Commun. 2001, 2152-2153.

Biographical sketch

Dr. Jenkins completed his B.A. in chemistry from Cornell University in 2000, where he conducted research with Prof. Héctor Abruña on the synthesis and electrochemistry of phenanthroline-based copper complexes. He received his Ph.D. from the California Institute of Technology in 2005, under the direction of Prof. Jonas Peters, for his study of low-spin pseudo-tetrahedral cobalt(II) complexes. While at Caltech, Dr. Jenkins synthesized the first cobalt-imide complex. Dr. Jenkins then joined the laboratory of Prof. Jeffrey Long as a Miller Institute for Basic Research postdoctoral fellow at the University of California, Berkeley. His research at U.C. Berkeley focused on the development of pentadentate capping ligands for utilization in single-molecule magnets and other magnetic materials. Dr. Jenkins joined the faculty of the University of Tennessee in 2008.

David Jenkins

409 Buehler Hall
Knoxville, TN 37996-1600
Phone: (865) 974-8591
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