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Estelle
Lebeau (Associate Professor)
Ph.D., University of
North Carolina at Chapel Hill, 1997
B.S., Bates College,
1991
Office:
368 Dow
Phone:
(989) 774 - 3116
Fax:
(989) 774 - 3883
E-mail:
lebea1el@mail.cmich.edu
Research Program and
Goals:
Two of the projects in my group involve studying the
reaction mechanisms of oxidation processes by metal catalysts in solution and in
solid media. The third project involves the development of a new carbon fiber
based battery.
1. Polynuclear aromatic hydrocarbons (PAH's) are a
general class of carcinogenic compounds prevalent in coal, automobile exhaust,
tobacco smoke, and petroleum products; thus, PAH's pose a significant biological
hazard. Current efforts concentrate on understanding the oxidative degradation
of the parent compounds of this class of carcinogens, phenanthrene and
anthracene, through a systematic study using Ru-based oxidation catalysts.
Efforts are underway to optimize catalyst performance through ligand
modification and sol-gel incorporation.
2. We are investigating the ability of various
non-aqueous electrolyte solutions and pastes to conduct electricity under
air-free and water-free conditions over a large temperature range. The ultimate
goal of this project is to use these electrolytes between Nugen™ carbon fiber
electrodes in the development of a flexible, lightweight energy storage device
(battery). This work has tremendous potential to facilitate the development of
non-fossil fuel support for transportation, particularly for personal
automation. The results of this work could have wide and significant societal
impact.
3. Cytochrome c oxidase (CcO) is an important enzyme
in the respiratory cycle of many life forms. Once in the cell, oxygen binds to
the enzyme and is converted to water and energy. A study of the structure of
cytochrome c oxidase and similar proteins, like hemoglobin, will allow for a
better understanding of the mechanism of oxygen conversion into water and the
overall cellular respiration process. Toward achieving this understanding, a
series of reduced, heteronuclear heme-copper (FeII/CuI) or reduced
FeII-porphyrin complexes that are designed to mimic the active centers of these
biological heme-containing enzymes will be synthesized within sol-gel matrices.
Reactivity studies will be performed to further elucidate influences of subtle
changes in environment upon complex activity toward oxygen binding and
subsequent reduction to water. Included amongst these fully-reduced biomimics
are carbonmonoxy and isocyanide ligated derivatives of covalently-linked model
compounds because these ligands stabilize the reduced states, FeII and CuI.
Reactivity studies, focusing upon photolytic displacement of these ligands, will
be performed to further elucidate influences of subtle changes in ligand
coordination environment upon complex reactivity toward O2 binding and ligand
recombination. Tethering the heme to the sol-gel matrix will inhibit direct
heme-heme reactivity, similar to the protein backbone in natural systems. A
ligand bridged Fe-X-Cu center has been implicated in the CcO catalytic cycle.
Several "mixed valence" (FeII/CuII) tethered heme/copper complexes
will be synthesized and characterized to mimic the spectral and reactivity
characteristics of the native enzyme. These complexes may have relevance with
regard to the energy translocation and storage required for proton pumping
across the mitochondrial membrane in CcO. This aspect of the project is designed
to answer the questions regarding ligand shuttling after photoinitiated
intervalence charge transfer in these novel bimetallic systems.
Selected Publications:
1. Lebeau, E. L., “Instability of the Oxidation Catalysts [OsIII(bpy)3]3+
and [OsIII(tpy)(bpy)(py)]3+ in Alkaline Solution,” Journal of Molecular Catalysis A: Chemical, 2004, 212 (1-2), 83-89.
2. Lebeau, E. L.,
Kusowski, R.; Renne, D.; “Oxidation of Select PAHs by [(bpy)2(py)RuIV(O)]2+
in Solution and Silica Sol-Gel Media,” J. Und. Chem. Res., 2003, 3, 101-105.
3. Kretzer,
R.M.; Ghiladi, R.A.; Lebeau, E.L.; Liang, H.-C.; Karlin, K.D., “Synthesis and Characterization of Reduced
Heme and Heme/Copper Carbonmonoxy Species” Inorg. Chem., 2003, 42, 3016-3025.
4. Peters, T. L.; Kusowski, R.; Renne, D. and Lebeau, E. L.
"Oxidation of Anthracene and Phenanthrene by a High Valent Ruthenium
Catalyst in a Sol-Gel Matrix." J.
Und. Chem. Res., 2003, 1,
15-19.
5. Thompson, D. W.; Kretzer, R. M.; Lebeau, E. L.; Scaltrito, D. V.;
Ghiladi, R. A.; Lam, K-C; Rheingold, A. L.;
Karlin, K. D.; Meyer, G. J. “Synthesis, Characterization, and Laser Flash
Photolysis Reactivity of a Carbonmonoxy Heme Complex.” ” Inorg. Chem., 2003, 42, 5211-5218.
6. Peters, T. L. and Lebeau, E. L. "Oxidation of Select PAHs by a
High Valent Ruthenium Catalyst in a Sol-Gel Matrix." Inorg. Chem., 2002,
submitted (reviewed, will be resubmitted as a full paper rather than a Communication
to the Editor).
7. Lebeau,
E. L.; Binstead, R. A.; Meyer, T. J., “Mechanistic Implications of Proton
Transfer Coupled to Electron Transfer,” J.
Am. Chem. Soc., 2001, 123, 10535-10544.
8. Lebeau,
E. L.; Meyer, T. J., “Oxidation of
Benzyl Alcohol by a Dioxo Complex of Ruthenium(VI),” Inorg. Chem., 1999,
38, 2174-2181.
9. Lebeau,
E. L.; Adeyemi, S. A.; Meyer, T. J., “Water Oxidation by [(tpy)(H2O)2RuIIIO-RuIII(H2O)2(tpy)]4+”
Inorg. Chem. 1998, 37, 6476-6484.
10. Wenzel,
T. J.; Bogyo, M. S.; Lebeau, E. L., “Lanthanide-Cyclodextrin Complexes as
Probes for Elucidating Optical Purity by NMR Spectroscopy,” J. Am. Chem. Soc. 1994, 116, 4858-4865.
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