David Bocian
Professor
Biophysical/Physical-Inorganic/Materials Chemistry
B.S., 1972, North Carolina State University
Ph.D., 1976, University of California, Berkeley
Postdoctoral Fellow, 1976-1979, California Institute of Technology
Research Interests:
Our research group is engaged in studies of energy-transducing systems including heme and photosynthetic proteins, synthetic light-harvesting arrays, molecular photonic devices, and electrically addressable molecular memories. We are also interested in the characterization of the structural, electronic, and magnetic properties of metallotetrapyrroles and other transition metal complexes and in the elucidation of the molecular structure and organization of monolayer assemblies of partially oriented systems. The investigative strategy common to all of our work is the implementation of a variety of techniques in order to provide a broad base of information that can be used to characterize the physical properties of the systems thoroughly and rigorously. These techniques include resonance Raman, infrared, absorption and electron paramagnetic resonance spectroscopies as well as electrochemical methods. The long-term goal is to provide a basis for relating the physical properties of the systems to their functional behavior (redox, ligand binding, light-energy conversion, energy/electron transfer, optoelectronic gating, information storage).
Heme and Other Metalloproteins: Heme and other metalloproteins that contain tetrapyrroles (porphyrins, chlorins, corphinoids) perform a wide variety of biochemical functions. We are performing spectroscopic studies on a variety of proteins including myoglobin, hydroxylamine oxido-reductase, and methyl coenzyme-M reductase in order to elucidate the physico-chemical properties of the active sites. Certain of these studies involve wild-type as well as genetically modified proteins.
Photosynthetic Proteins: Photosynthetic proteins convert light into chemical energy in certain bacteria and higher plants. We are conducting vibrational studies on reaction centers from various bacteria, including Rb. sphaeroides, Rb. capsulatus and Rps. viridis, and on the photosystem I and II core complexes from higher plants. These data are being used for a detailed characterization of the structural properties of the (bacterio)chlorin cofactors and how these properties are influenced by pigment-protein interactions. All of these studies involve wild-type as well as genetically modified proteins.
Porphyrin-Based Molecular Photonic Devices: Electronic interactions between porphyrinic p systems in close proximity play a pivotal role in such diverse systems as photosynthetic proteins, artificial light-harvesting systems, and organic conductors. We are examining a variety of synthetic stacked and bridged dimeric, trimeric and multimeric porphyrinic arrays using optical, vibrational, and magnetic spectroscopies. Our efforts are directed at probing electronic communication in these assemblies with the aim of developing a strategy for the rational design and construction of nanoscale photonic devices.
Porphyrin-Based Molecular Memories: The continued miniaturization of information processing systems requires the development of components with feature sizes of less than 0.1 micron. While such feature sizes will most likely be achieved with projected technologies, it is uncertain whether devices that rely on the bulk properties of semiconductor materials will retain the required functional characteristics at these dimensions. Accordingly, there is much interest in using molecules to replace semiconductor materials. Our efforts in this area focus on the use of porphyrins as information storage media in next-generation memory elements.
Selected Publications
Tang, Q.; Carrington, P. E.; Horng, Y-C.; Maroney, M. J.; Ragsdale, S. W.; Bocian, D. F. "X-Ray Absorption and Resonance Raman Studies of Methyl-Coenzyme M Reductase Indicating that Ligand Exchange and Macrocycle Reduction Accompany Reductive Activation," J. Am. Chem. Soc. 2002, 124, 13242-13256.
Kirmaier, C.; Cua, A.; He, C.; Holten, D.; Bocian, D. F. "Probing M-Branch Electron Transfer and Cofactor Environment in the Bacterial Photosynthetic Reaction Center by Addition of a Hydrogen Bond to the M-Side Bacteriopheophytin," J. Phys. Chem. B 2002, 106, 495-503.
Cua, A.; Vrettos, J. S.; de Paula, J. C.; Brudvig, G. W.; Bocian, D. F. "Raman Spectra and Normal Coordinate Analyses of Low-Frequency Vibrations of Oxo-bridged Manganese Complexes," J. Biol. Inorg. Chem. 2003, 8, 439-451.
Holten, D.; Bocian, D. F.; Lindsey, J. S. "Probing Electronic Communication in Covalently Linked Multiporphyrin Arrays. A Guide to the Rational Design of Molecular Photonic Devices," Acc. Chem. Res. 2002, 35, 57-69.
Roth, K. M.; Gryko, D. T.; Clausen, C.; Gryko, D.; Li, J.; Lindsey, J. S.; Kuhr, W. G.; Bocian, D. F. "Comparison of Electron-Transfer and Charge-Retention Characteristics of Porphyrin-Containing Self-Assembled Monolayers Designed for Molecular Information Storage," J. Phys. Chem. B 2002, 106, 8639-8648.
Roth, K. M.; Yasseri, A. A.; Liu, Z.; Dabke, R. B.; Malinovskii, V.; Schweikart, K-H.; Yu, L.; Tiznado, H.; Zaera, F.; Lindsey, J. S.; Kuhr, W. G.; Bocian, D. F. "Measurement of Electron-Transfer Rates of Charge-Storage Molecular Monolayers on Si(100). Towards Hybrid Molecular/Semiconductor Information Storage Devices," J. Am. Chem. Soc. 2003, 125, 505-517.
WWW: Research
Email: david.bocian@ucr.edu
Extension: 3660
Professor
Biophysical/Physical-Inorganic/Materials Chemistry
B.S., 1972, North Carolina State University
Ph.D., 1976, University of California, Berkeley
Postdoctoral Fellow, 1976-1979, California Institute of Technology
Research Interests:
Our research group is engaged in studies of energy-transducing systems including heme and photosynthetic proteins, synthetic light-harvesting arrays, molecular photonic devices, and electrically addressable molecular memories. We are also interested in the characterization of the structural, electronic, and magnetic properties of metallotetrapyrroles and other transition metal complexes and in the elucidation of the molecular structure and organization of monolayer assemblies of partially oriented systems. The investigative strategy common to all of our work is the implementation of a variety of techniques in order to provide a broad base of information that can be used to characterize the physical properties of the systems thoroughly and rigorously. These techniques include resonance Raman, infrared, absorption and electron paramagnetic resonance spectroscopies as well as electrochemical methods. The long-term goal is to provide a basis for relating the physical properties of the systems to their functional behavior (redox, ligand binding, light-energy conversion, energy/electron transfer, optoelectronic gating, information storage).
Heme and Other Metalloproteins: Heme and other metalloproteins that contain tetrapyrroles (porphyrins, chlorins, corphinoids) perform a wide variety of biochemical functions. We are performing spectroscopic studies on a variety of proteins including myoglobin, hydroxylamine oxido-reductase, and methyl coenzyme-M reductase in order to elucidate the physico-chemical properties of the active sites. Certain of these studies involve wild-type as well as genetically modified proteins.
Photosynthetic Proteins: Photosynthetic proteins convert light into chemical energy in certain bacteria and higher plants. We are conducting vibrational studies on reaction centers from various bacteria, including Rb. sphaeroides, Rb. capsulatus and Rps. viridis, and on the photosystem I and II core complexes from higher plants. These data are being used for a detailed characterization of the structural properties of the (bacterio)chlorin cofactors and how these properties are influenced by pigment-protein interactions. All of these studies involve wild-type as well as genetically modified proteins.
Porphyrin-Based Molecular Photonic Devices: Electronic interactions between porphyrinic p systems in close proximity play a pivotal role in such diverse systems as photosynthetic proteins, artificial light-harvesting systems, and organic conductors. We are examining a variety of synthetic stacked and bridged dimeric, trimeric and multimeric porphyrinic arrays using optical, vibrational, and magnetic spectroscopies. Our efforts are directed at probing electronic communication in these assemblies with the aim of developing a strategy for the rational design and construction of nanoscale photonic devices.
Porphyrin-Based Molecular Memories: The continued miniaturization of information processing systems requires the development of components with feature sizes of less than 0.1 micron. While such feature sizes will most likely be achieved with projected technologies, it is uncertain whether devices that rely on the bulk properties of semiconductor materials will retain the required functional characteristics at these dimensions. Accordingly, there is much interest in using molecules to replace semiconductor materials. Our efforts in this area focus on the use of porphyrins as information storage media in next-generation memory elements.
Selected Publications
Tang, Q.; Carrington, P. E.; Horng, Y-C.; Maroney, M. J.; Ragsdale, S. W.; Bocian, D. F. "X-Ray Absorption and Resonance Raman Studies of Methyl-Coenzyme M Reductase Indicating that Ligand Exchange and Macrocycle Reduction Accompany Reductive Activation," J. Am. Chem. Soc. 2002, 124, 13242-13256.
Kirmaier, C.; Cua, A.; He, C.; Holten, D.; Bocian, D. F. "Probing M-Branch Electron Transfer and Cofactor Environment in the Bacterial Photosynthetic Reaction Center by Addition of a Hydrogen Bond to the M-Side Bacteriopheophytin," J. Phys. Chem. B 2002, 106, 495-503.
Cua, A.; Vrettos, J. S.; de Paula, J. C.; Brudvig, G. W.; Bocian, D. F. "Raman Spectra and Normal Coordinate Analyses of Low-Frequency Vibrations of Oxo-bridged Manganese Complexes," J. Biol. Inorg. Chem. 2003, 8, 439-451.
Holten, D.; Bocian, D. F.; Lindsey, J. S. "Probing Electronic Communication in Covalently Linked Multiporphyrin Arrays. A Guide to the Rational Design of Molecular Photonic Devices," Acc. Chem. Res. 2002, 35, 57-69.
Roth, K. M.; Gryko, D. T.; Clausen, C.; Gryko, D.; Li, J.; Lindsey, J. S.; Kuhr, W. G.; Bocian, D. F. "Comparison of Electron-Transfer and Charge-Retention Characteristics of Porphyrin-Containing Self-Assembled Monolayers Designed for Molecular Information Storage," J. Phys. Chem. B 2002, 106, 8639-8648.
Roth, K. M.; Yasseri, A. A.; Liu, Z.; Dabke, R. B.; Malinovskii, V.; Schweikart, K-H.; Yu, L.; Tiznado, H.; Zaera, F.; Lindsey, J. S.; Kuhr, W. G.; Bocian, D. F. "Measurement of Electron-Transfer Rates of Charge-Storage Molecular Monolayers on Si(100). Towards Hybrid Molecular/Semiconductor Information Storage Devices," J. Am. Chem. Soc. 2003, 125, 505-517.
WWW: Research
Email: david.bocian@ucr.edu
Extension: 3660