RESEARCH AREAS

David M. Tiede

David M. Tiede Senior Scientist and Group Leader Argonne National Laboratory P: 630-252-3539 E: tiede@anl.gov Tiede Research Group B.A., University of Pennsylvania; Ph.D., University of Pennsylvania

Biographical Sketch

David Tiede is the Photosynthesis group leader in Argonne’s Chemical Sciences and Engineering Division. He also was a founding Scientific Theme Leader in Argonne’s Center for Nanoscale Materials, and serves as an elected member of the User Organization Steering Committee for the Advanced Photon Source.

Research Statement

Research in the Argonne’s Photosynthesis program is directed at resolving mechanisms responsible for optimization of photochemical energy conversion in natural photosynthesis, and in using this information for the development of artificial or bio-hybrid photochemical systems with enhanced photochemical energy conversion efficiency. Our program investigates correlations between sequential electron transfer with static and dynamic structures in natural and artificial systems, and investigates strategies for linking ultrafast, light-induced, one-electron transfer to slower, energy-conserving redox and electrochemical processes in artificial photosynthetic systems using biomimetic, hierarchical molecular architectures. Synthetic approaches are being investigated for creating new solar fuels catalysts by exploiting biology as a source of unique frameworks tuned for catalysis, and augmenting these with synthetic light-harvesting pigments and metal complexes to achieve molecular hybrids that employ biological mechanisms for efficient catalysis, but that are realized in a broader range of molecular charge carriers and reaction matrices than can be achieved using biological or chemical approaches alone.

A key feature of our research program has been our development of synchrotron wide-angle X-ray scatting techniques that provide new opportunities for structural resolution of solar energy converting materials in a range of non-crystalline media that are most pertinent to solar energy converting function.  Particular highlights have been development of experimental approaches that allow solution-state supramolecular structure measurements to be made to better that 1 angstrom spatial resolution, and the development of coordinate-based analysis that allows scattering data to be quantitatively interpreted in terms of detailed coordinate models and dynamic simulations. This program highlights the direct detection of atomic reorganization accompanying photochemical charge separation by exploiting recently developed pump-probe time-resolved synchrotron x-ray scattering techniques to follow light-activated structural dynamics across multiple time (10-10 sec to 1 sec ) and length (1 Å to 103 Å) scales.

As a complement the x-ray structural studies, ultrafast optical techniques are also being developed in collaboration with Argonne’s Center for Nanoscale Materials (CNM)  to image light-harvesting and photosynthetic charge separation function across the “nested” hierarchies of structure in photosynthesis that are comprised of ensembles of cofactors packed within individual light-harvesting and reaction center proteins, which are in turn organized into quasi-crystalline functional arrays in natural photosynthetic membranes, and in laboratory-produced 2D and 3D crystalline arrays of isolated photosynthetic proteins.  This project combines ultrafast transient laser spectroscopy with advances in nanophotonics techniques for spatial control and imaging of light at the nanoscale.  This work is targeted at resolving the design principles that underlie Nature’s remarkable hierarchical architectures for solar energy conversion, and it will establish approaches for follow-on research on the design and analysis of efficient, molecular-based biomimetic systems for solar energy capture and conversion.

Publications

• “The Conformational Ensemble of a Hexameric Porphyrin Array Characterized Using Molecular Dynamics and Wide-Angle X-ray Scattering,” K. L. Mardis, H. M. Sutton, X. Zuo, J.S. Lindsey, and D. M. Tiede, J. Phys. Chem. B in press (2009).
• “Femtosecond Spectroscopy of Single Photosynthetic Reaction Center Crystals from Rhodobacter sphaeroides,” L. Huang, G.P. Wiederrecht, S. Schlesselman, C. Xydis, P.D. Laible, D.K. Hanson, D.M. Tiede, Biochemistry 47: 11387-11389 (2008).
• “Coordinative Self-Assembly and Solution-phase X-ray Structural Characterization of Cavity-Tailored Porphyrin Boxes,” S. J. Lee, K. L. Mulfort, X. Zuo, A. J. Goshe,P. J. Wesson, J. T. Hupp, and D. M. Tiede,  J. Am. Chem. Soc. 130, 836-838 (2008).
• “Solution-phase structural characterization of supramolecular assemblies by high-angle molecular diffraction,” J.L. O'Donnell, X. Zuo, A.J. Goshe, L. Sarkisov, R. Q. Snurr, J. T. Hupp, D. M. Tiede, J. Am. Chem. Soc., 129, 1578-1585 (2007)
• “X-ray Diffraction “Fingerprinting” of DNA Structure in Solution for Quantitative Evaluation of Molecular Dynamics Simulation,” X. Zuo, G. Gui, K.M. Merz, L. Zhang, F.D. Lewis, and D.M. Tiede, Proceed. Natl. Acad. Sci. USA, 103 (10), 3534-3539 (2006).

Most Significant Honors & Awards

• Fellow, American Association for the Advancement of Science
• Argonne National Laboratory Director's Award
• Argonne National Laboratory Pacesetter Award (1986)