Dewey Holten
Campus Box 1134
Research Interests
Our research encompasses (1) the primary reactions of photosynthesis and (2) tetrapyrroles chromophores and arrays for applications in solar-energy conversion, molecular materials, and photomedicine. The techniques employed include static and laser-based femtosecond to seconds time-resolved absorption and emission spectroscopy.
Primary Processes in the Photosynthetic Reaction Center. The goal of our photosynthesis research is to achieve a molecular-level understanding of the primary charge separation process in the bacterial reaction center. In this pigment-protein complex, light energy is converted into chemical potential energy by a series of fast electron transfers across the membrane from the photoexcited bacteriochlorophyll special dimer along a chain of electron acceptors on the photoactive A-branch with a quantum yield of ~1. We have been preparing and studying mutants with altered free energies of the charge separated states that modulate the yields of charge separation versus recombination and give electron transfer fully down the normally inactive B branch.
Tetrapyrrole Chromophores and Arrays. We are investigating the electronic and photophysical properties of tetrapyrrole (porphyrin, chlorin, bacteriochlorin) chromophores. The various applications require specifically tuned photophysical properties such as absorption and fluorescence wavelengths and intensities, and excited-state lifetimes. We are similarly studying energy and electron transfer reactions in arrays of porphyrins and other chromophores that serve as light-harvesting or charge-transfer systems. Both the chromophores and arrays should be useful for a variety of applications in solar-energy conversion and photomedicine, including photodynamic therapy and optical molecular imaging.
Appointments
2007-present, Member, Imaging Sciences Pathway
2005-present, Member, CMI
1989-present, Professor, Department of Chemistry, Washington University
1986-1989, Associate Professor, Departmentof Chemistry, Washington University
1980-present, Member, DBBS
1980-1986, Assistant Professor, Department of Chemistry, Washington University
1977-1980, Postdoctoral Fellow, University of Washington, Seattle
Centers
Selected Publications
J. R. Stromberg, A. Marton, H. L. Kee, C. Kirmaier, J. R. Diers, C. Muthiah, M. Taniguchi, J. S. Lindsey, D. F. Bocian, G. J. Meyer, and D. Holten, “Examination of Tethered Porphyrin, Chlorin, and Bacteriochlorin Molecules in Mesoporous Metal-Oxide Solar Cells,” J. Phys. Chem. C., 2007, 111, 15464-15478.
C. Kirmaier and D. Holten, “Low-Temperature Studies of Electron Transfer to the M-Side of YFH Reaction Centers from Rhodobacter capsulatus,” J. Phys. Chem. B., 2009, 113, 1132-1142.
H. L. Kee, J. R. Diers, M. Ptaszek, C. Muthiah, D. Fan, J. S. Lindsey, D. F. Bocian, and D. Holten, "Chlorin-Bacteriochlorin Energy-Transfer Dyads as Prototypes for Near-infrared Molecular Imaging Probes: Controlling Charge-Transfer and Fluorescence Properties in Polar Media," Photochem. Photobiol., 2009, 85, 909-920.
B. Carter, S. G. Boxer, D. Holten, and C. Kirmaier, "Trapping the P+BL- Initial Intermediate State of Charge Separation in Photosynthetic Reaction Centers from Rhodobacter capsulatus," Biochemistry, 2009, 48, 2571-2573.
H. Song, M. Taniguchi, J. R. Diers, C. Kirmaier, D. F. Bocian, J. S. Lindsey, and D. Holten, “Linker Dependence of Energy and Hole Transfer in Neutral and Oxidized Multiporphyrin Arrays,” J. Phys. Chem. B., 2009, 113, 16843-16493.
Y.-Y. Huang, P. Mroz, T. Zhiyentayev, T. Balasubramanian, C. Ruzié, M. Krayer, D. Fan, K. E. Borbas, E. Yang, H. L. Kee, C. Kirmaier, J. R. Diers, D. F. Bocian, D. Holten, J. S. Lindsey, and M. R. Hamblin, "In vitro Photodynamic Therapy and Quantitative Structure Activity Relationship Studies with Stable Synthetic Near-Infrared-Absorbing Bacteriochlorin Photosensitizers," J. Med. Chem. 2010, 53, 4018-4027.
C. Kirmaier, H. Song, E. Yang, J. K. Schwartz, E. Hindin, J. R. Diers, R. S. Loewe, K-Y Tomizaki, F. Chevalier, L. Ramos, R. R. Birge, J. S. Lindsey, D. F. Bocian, and D. Holten, “Excited-State Photodynamics of Perylene–Porphyrin Dyads 5. Tuning Light-Harvesting Characteristics via Perylene Substituents, Connection Motif and 3-Dimensional Architecture,” J. Phys. Chem. B. 2010, 114, 14249-14264.
O. Mass, M. Taniguchi, M. Ptaszek, J. W. Springer, K. M. Faries, J. R. Diers, D. F. Bocian, D. Holten, and J. S. Lindsey, Structural Characteristics that Make Chlorophylls Green: Interplay of Hydrocarbon Skeleton and Substituents, N. J. Chem. 2011, 35, 76-88.
Photophysical Properties and Electronic Structure of Stable, Tunable Synthetic Bacteriochlorins: Extending the Features of Native Photosynthetic Pigments, E. Yang, C. Kirmaier, M. Krayer, M. Taniguchi, H-J Kim, J. R. Diers, D. F. Bocian, J. S. Lindsey, and D. Holten J. Phys. Chem. B. 2011, 115, 10801-10816.
De novo Synthesis and Properties of Analogues of the Self-Assembling Chlorosomal Bacteriochlorophylls, O. Mass, D. R. Pandithavidana, M. Ptaszek, K. Santiago, J. W. Springer, J. Jiao, Q. Tang, C. Kirmaier, D. F. Bocian, D. Holten, and J. S. Lindsey N. J. Chem 2011, 35 2671-2690.
Awards
2009, Outstanding Mentor Award, Washington University Graduate Student Senate
1999, Midwest Award (for Achievement in Chemistry, St. Louis Section of the ACS)
1991, Washington University Morter Board Teacher of the Month (November)
1989, St. Louis Award (St. Louis Section of the American Chemical Society)
1980, Camille and Henry Dreyfus Award for Newly Appointed Young Faculty in Chemistry
1977, NSF National Needs Postdoctoral Fellow
Courses
Chemistry 111, General Chemistry
Chemistry 151 General Chemistry Lab I
Chemistry 152 General Chemistry Lab II
Chemistry 442, Quantum Chemistry
Chemistry 445, Instrumental Methods in Physical Chemistry Laboratory
Chemistry 574, Optical Properties of Molecules