Campus Box 1134
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 to (1) probe the contributions of energetics versus electronic interactions to the directionality of electron transfer, (2) modulate the rate constants and yields of charge separation versus recombination at each step on both branches, and (3) give electron transfer fully down the normally inactive B branch.
Our studies of tetrapyrrole chromophores (porphyrin, chlorin, bacteriochlorin) chromophores are aimed at elucidating the fundamental interplay between molecular composition, electronic structure, and photophysical properties. These properties include absorption and emission spectra and the rate constants and yields of the singlet excited-state decay pathways (fluorescence, internal conversion, intersystem crossing). Studies of multichromophore arrays probe fundamental aspects of energy and electron transfer and include design and characterization of biohybrid light-harvesting architectures that integrate designer chromophores with native-like peptide scaffolds to enhance solar coverage.
2007-present, Member, Imaging Sciences Pathway
2005-2013, Member, CMI
2013- present, Member, IMSE
1989-present, Professor, Department of Chemistry, Washington University
1986-1989, Associate Professor, Department of Chemistry, Washington University
1980-present, Member, DBBS
1980-1986, Assistant Professor, Department of Chemistry, Washington University
1977-1980, Postdoctoral Fellow, University of Washington, Seattle
Effects of Substituents on Synthetic Analogs of Chlorophylls. Part 4: How Formyl Group Location Dictates the Spectral Properties of Chlorophylls b, d and f, J. M. Yuen, M. A. Harris, M. Liu, J. R. Diers, C. Kirmaier, D. F. Bocian, J. S. Lindsey and D. Holten, Photochem. Photobiol.2015, 91, 331-342.
Photophysical Properties and Electronic Structure of Chlorin-Imides: Bridging the Gap Between Chlorins and Bacteriochlorins, K. M. Faries, J. R. Diers, J. W. Springer, E. Yang, M. Ptaszek, D. Lahaye, M. Krayer, M. Taniguchi, C. Kirmaier, J. S. Lindsey, D. F. Bocian, and D. Holten, J. Phys. Chem. B, 2015, 119, 7503-7515.
Extending the Short and Long Wavelength Limits of Bacteriochlorin Near-Infrared Absorption via Dioxo- and Bisimide-Functionalization, P. Vairaprakash, E. Yang, T. Sahin, M. Taniguchi, M. Krayer, J. R. Diers, A. Wang, D. M. Niedzwiedzki, C. Kirmaier, J. S. Lindsey, D. F. Bocian, and D. Holten, J. Phys. Chem. B, 2015, 119, 4382-4995.
Functional Characteristics of Spirilloxanthin and Keto-Bearing Analogues in Light-Harvesting LH2 Complexes from Rhodobacter sphaeroides with a Genetically Modified Carotenoid Synthesis Pathway, D. M. Niedzwiedzki, P. L. Dilbeck, Q. Tang, D. J. Mothersole, E. C. Martin, D. F. Bocian, D. Holten, and C. N. Hunter, Biochim. Biophys. Acta, 2015, 1847, 640-655.
Self-Assembled Light-Harvesting System from Chromophores in Lipid Vesicles, T. Sahin, M. A. Harris, P. Vairaprakash, D. M. Niedzwiedzki, V. Subramanian, A. P. Shreve, D. F. Bocian, D. Holten and J. S. Lindsey, J. Phys. Chem. B, 2015, 119, 10231-10243.
Optimizing Multi-Step B-side Charge Separation in Photosynthetic Reaction Centers from Rhodobacter capsulatus, K. M. Faries, L. Kressel, N. P. Dylla, Marc J. Wander, D. K. Hanson, D. Holten, P. D. Laible, C. Kirmaier, Biochem. Biophys Acta. 2016, 1857,150-159.
Effects of Strong Electronic Coupling in Chlorin and Bacteriochlorin Dyads, H. S. Kang, N. N. Esemoto, J. R. Diers, D. M. Niedzwiedzki, J. A. Greco, J. Akhigbe, Z. Yu, C. Pancholi, G. V. Bhagavathy, J. K. Nguyen, C. Kirmaier, R. R. Birge, M. Ptaszek, D. Holten and D. F. Bocian, J. Phys. Chem. A. 2016, 120, 379-395.
Quenching Capabilities of Long-Chain Carotenoids in Light-Harvesting-2 Complexes from Rhodobacter sphaeroides with an Engineered Carotenoid Synthesis Pathway, P. L. Dilbeck, Q. Tang, D. J. Mothersole, E. C. Martin, C. N. Hunter, D. F. Bocian, D. Holten, D. M. Niedzwiedzki, J. Phys. Chem. B. 2016, 120, 5429-5443.
Species Differences in Unlocking B-side Electron Transfer in Bacterial Reaction Centers, N. P. Dylla, K. M. Faries, R. M. Wyllie, A. M. Swenson, D. K. Hanson, D. Holten, C. Kirmaier and P. D. Laible, Febs Lett., 2016, 590, 2515-2526.
Tuning the Electronic Structure and Properties of Perylene–Porphyrin–Perylene Panchromatic Absorbers, J. Amanpour, G. Hu, E. J. Alexy, A. K. Mandal, H. S. Kang, J. M. Yuen, J. R. Diers, D. F. Bocian, J. S. Lindsey, and D. Holten, J. Phys. Chem. A., 2016, 120, 7434-7450.
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
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