FACULTY Center members include BGSU faculty from the Departments of Chemistry, Physics and Astronomy, and Biological Sciences. Its unifying intellectual theme focuses on the study of the interaction of light with physical, chemical, and biological systems, and on the quest for practical applications of that basic knowledge, which stimulate new technology. Faculty in the Center for Photochemical Sciences strive to expand the synergy of research, teaching, and applications in the photochemical sciences. ============================================================= Pavel Anzenbacher, Jr. Associate Professor of Chemistry Ph.D., Czech Academy of Science (Prague), 1996 The design and synthesis of novel dyes and pigments, electroluminescent materials for organic light-emitting diode (OLED) applications as well as supramolecular aspects of molecular sensing is the focus of our research group. Our primary interest is in nanotechnology as it is applied to molecular sensing with particular attention being devoted to the sensing of anionic analytes. We are also interested in the design aspects of electroluminophores with tunable light output aimed at application in flat-panel displays. E-mail: pavel@bgsu.edu Phone: 419-372-2080 George S. Bullerjahn Professor of Biological Sciences Ph.D., University of Virginia, 1984 Our work is currently focused on the regulation of nutrient-stress-inducible genes in cyanobacteria. We have identified genes and gene products inducible under nutrient (N, S, P) limitation and stationary phase conditions, and this work may help define universal rules in the adaptation of bacteria to changing and extreme environments. Additionally, we are working on understanding the structure and dynamics of photosynthetic complexes in the chl a/b containing prokaryote Prochlorothrix. Such work will help in the understanding of how phototrophs can colonize low light habitats. E-mail: bullerj@bgsu.edu Phone: 419-372-8527 John R. Cable Chair and Associate Professor of Chemistry Ph.D., Cornell University, 1986 Our work currently focuses on determining the structures of conformationally flexible molecules and the effect that solvation and hydrogen bonding has on these structures using vibrationally resolved electronic spectroscopy in the ultracold environment of a supersonic jet expansion. Electronic spectroscopy permits structural information to be obtained on both ground and excited electronic states through analysis of the resolved vibrational structure that appears under these conditions. We are currently investigating a number of phenyl-substituted amines and amides. These types of molecules form strong hydrogen bonds with a variety of partners, including water, and have the potential to act as both donors and acceptors. By studying hydrogen bonded clusters at high spectral resolution, it is possible to determine the mode of binding between the solute and solvent as well as to characterize the structural perturbations that arise from the strong interaction. E-mail: cable@bgsu.edu Phone: 419-372-8439 Felix N. Castellano Professor of Chemistry Ph.D., Johns Hopkins University, 1996 Our current research focus involves the photochemistry and photophysics of metal-organic chromophores, where the proper combination of metal complex and organic subunit(s) yield new luminescent molecules or assemblies with distinct properties and potentially useful functions. Most of the chromophores of interest are centered around copper(I), platinum(II), ruthenium(II), and osmium(II) coordination and organometallic complexes. From the fundamental perspective, we are interested in the interplay of closely-lying excited states and the influence these interactions have on the resulting photophysics. These processes are investigated with a battery of static and time-resolved spectroscopic techniques, the latter revealing excited state dynamics evolving from the femtosecond regime to milliseconds. We have recently developed photochemical schemes, which result in low power photon upconversion; wavelength shifting incident light to higher energy. This approach also provides a means to access traditional ultraviolet-driven photochemical reactions using visible photons. We are intensively investigating a variety of alternative energy-relevant projects including next generation photovoltaic materials, photocatalytic solar fuels production, and water splitting photochemistry. Photoinduced electron transfer at the molecule/semiconductor interface represents an important facet of these inquiries. A more recent endeavor features molecular structures possessing intimate d8-d8 metal-metal interactions for in-depth studies of intramolecular excited state bond formation in addition to photo-initiated electron and energy transfer chemistry. E-mail: castell@bgsu.edu Phone: 419-372-7513 Ksenija D. Glusac Assistant Professor of Chemistry Ph.D., University of Florida, 2003 Our main research focus is to study how natural flavins catalyze redox reactions and to use this acquired knowledge towards the development of efficient artificial catalysts. With a goal of understanding natural mechanisms of chemicallight energy conversion, we chose to study two flavoproteins: one that uses the Sun’s energy to drive a chemical reaction (DNA photolyase), and another that converts the energy of a chemical reaction to blue photons (bacterial luciferase). Inspired by the catalytic oxygen reduction in bacterial luciferases, we engineered an artificial, flavin-based system that catalyzes the reversal reaction: water oxidation to produce molecular oxygen. Our flavin-based compound is the first example of a fully organic compound that performs catalytic oxygen evolution. This process of catalytic water oxidation is essential for utilization of the Sun’s energy by means of solar fuel cells, and we expect the scientific community to be very interested in our findings. E-mail: kglusac@bgsu.edu Phone: 419-372-3229 Jeremy K. Klosterman, Ph.D. Assistant Professor of Chemistry Ph.D., Universität Zürich (Switzerland), 2007 In the last fifty years, significant advances in materials science formed the foundation of modern electronics and enabled new possibilities in energy storage and environmentally friendly technologies. Crystal engineering, a recent branch of supramolecular chemistry with increasing significance, has helped shed light on the roles of intermolecular interactions in supramolecular solid-state structures. More recently, metal-organic frameworks (MOFs) combined organic and inorganic subunits to fashion robust, well-defined three-dimensional frameworks and provide easy access to the domain of solid state chemistry where specific intermolecular interactions can engender bulk, material properties. However, much remains unknown about the relationships between the molecular structure and the resultant material properties and, as a result, the search for new, functional materials too often relies on serendipitous discovery. The primary goal of our research is the design and synthesis of functional supramolecular architectures. This necessitates a thorough understanding of the relationships between the molecular structure, the supramolecular architecture, and the material properties. We are currently focusing on the following areas: The development of a modular approach to control fluorophore aggregation and orientation in the solid state in order to enhance solid-state emissive properties. The application of emissive organic solids towards new practical chemosensors. The combination of multiple intermolecular interactions to enable the molecular realization of mechanically linked, topologically complex structures. E-mail: jkloster@bgsu.edu Phone: 419-372-9450 Neocles B. Leontis Professor of Chemistry Ph.D., Yale University, 1986 Nucleic acids (DNA and RNA) play diverse roles in living organisms. Not only do they encode genetic information but they actively participate in its readout from transcription to translation, including splicing, editing, and regulation at each stage. Single-stranded DNA and RNA molecules fold into complex 3-dimensional structures to carry out these roles. We are investigating the logic of the 3D architecture of these molecules using an integrated biophysical, biochemical, and bioinformatic approach. These complex structures are able to specifically bind other molecules, including potential drug molecules. Photosensitizers that can specifically bind DNA or RNA molecules have tremendous potential for overcoming present limitations of photodynamic therapy, by directing damage to molecules specific to the target cells. We are investigating the binding of potent photosensitizers to complex nucleic acids using biophysical and biochemical methods. E-mail: leontis@bgsu.edu Phone: 419-372-8663 H. Peter Lu Ohio Eminent Scholar in Photochemical Sciences Professor of Chemistry Ph.D., Columbia University, 1991 Our research is focused on the use of single molecule techniques to understand molecular dynamic processes and the effects of the local environment on these processes. We have been developing and applying time-resolved, nanoscale site-specific, single molecule methods that are an effective alternative to conventional methods, providing information under conditions most applicable to the natural processes underlying the area of research interest. Singlemolecule approaches are useful and unique in studying heterogeneous and complex systems because the inhomogeneity can be identified and/or removed by studying one molecule at a time. Single molecules and molecular complexes can be observed as they traverse a wide range of energy states in real-time and the effect of this ever changing "system configuration" on chemical/biological reactions and other dynamical processes can be mapped. Our current research work has been focused on (1) conformational dynamics and reaction in proteins and protein complexes under physiological conditions, and our long-term goal is to study single-molecule protein conformational dynamics and reactions in living cells; and (2) inhomogeneous interfacial chemical and biological reaction dynamics in solar energy conversion, bioremediation, and environmental systems, focusing on fundamental understanding of the controlling physical and chemical properties, such as, Franck-Condon coupling and barrier, vibrational and solvent relaxation energetics, molecular distributions, redox states identification, and molecular motions. E-mail: hplu@bgsu.edu Phone: 419-372-1840 Michael Y. Ogawa Professor of Chemistry Ph.D., Northwestern University, 1987 Our group is developing a new class of hybrid inorganic/biological materials possessing novel photochemical properties. In one project we are using the principles of “metalloprotein design” to prepare a new class of miniature metalloproteins containing luminescent Cu(I) centers. The photophysical properties of these systems have been found to mimic many features found in natural photosynthetic reaction centers and can be used to develop new routes toward solar energy conversion. A related project uses supramolecular coordination chemistry to direct the assembly of novel peptide structures. We have found that such metal-mediated peptide assemblies possess a diverse range of morphologies ranging from nanometer-scale hollow spheres to nano-cylinders, making them possible candidates for drug delivery vehicles. Thus, a central theme of our laboratory is to combine inorganic coordination chemistry/photochemistry with protein design in order to prepare new types of hybrid materials, which possess potentially useful chemical properties. E-mail: mogawa@bgsu.edu Phone: 419-372-9231 Massimo Olivucci Research Professor of Chemistry Laboratory for Computational Photochemistry Ph.D., University of Bologna (Italy), 1988 We use conventional and novel computational tools to investigate the reactivity of organic and biological molecules in their electronically excited states. One major target of our work is the mapping of the photon-induced "force field" which sets an equilibrium molecular structure into motion in realistic molecular environments (e.g., in solution or in a protein cavity). We also investigate the reactive motion itself up to time scales beyond 10-12 seconds. This force field can be calculated and represented in terms of photochemical reaction paths: i.e., paths that start on an excited state potential energy surface and end on the ground state energy surface. Photochemical reaction paths comprise mechanistic elements that are not involved in the description of thermal reactions. These correspond to real crossings of different potential energy surfaces. For photochemical reactions prompted by direct irradiation these crossings often correspond to conical intersections that are regarded as the photochemical analogues of transition states. Given the central role of photochemical reaction paths, excited state trajectories and conical intersections (as well as singlet/triplet surface crossings) in the investigation of the excited state reactivity of proteins (e.g., biological photoreceptors) or solvated molecules (e.g., dyes in solution), we also develop computational strategies based on a combination of ab-initio quantum chemical methods and molecular mechanics methods that allow to study the effects of light irradiation on complex molecular systems. E-mail: molivuc@bgsu.edu Phone: 419-372-7606 Alexander N. Tarnovsky Assistant Professor of Chemistry Ph.D., S. I. Vavilov State Optical Institute, St. Petersburg (Russia), 1993 The focus of our research interests is two-fold: Developing a molecular-level understanding of the dynamics of chemical reactions occurring in solution, and; Gaining a deep, detailed insight into the dynamics and mechanisms of ultrafast (femtoand picosecond) photoinduced processes. Our primary interest is “real time” investigation of ultrafast excited-state dynamics, bond rupture, and rearrangement of liquid-phase small polyatomic molecules, with most attention currently centered on polyhalogenated alkanes and transition metal complexes. The knowledge of the interplay between the initially populated Franck-Condon region, adiabatic/non-adiabatic excited-state dynamics, energy flow and solute-solvent interactions, is of central importance for achieving control over the photoreaction path. In our research, we use state-of-the-art experimental methods of ultrafast time-resolved spectroscopy, primarily deep-UV-throughnear-IR pump/probe and laser pump/x-ray absorption probe. E-mail: atarnov@bgsu.edu Phone: 419-372-3865 Andrew T. Torelli, Ph.D. Assistant Professor of Chemistry University of Rochester, 2008 Research in the Torelli lab is broadly interested in the structural and chemical basis for enzyme function. The current focus is on enzymes that biosynthesize iron-sulfur (Fe-S) clusters (which are essential protein cofactors involved in a wide range of enzyme functions including electron transfer (e.g. respiration, photosynthesis), environmental sensing (e.g. redox homeostasis, iron deprivation), structural stabilization of protein folds and chemical catalysis (e.g. as Lewis Acids). While the earliest enzymes probably assimilated Fe-S clusters that formed spontaneously in the environment, the evolution of photosynthesis and subsequent oxygenation of the atmosphere depleted available environmental sources of ferrous iron ions through oxidation to insoluble ferric iron species. As a consequence, pathways emerged to biosynthesize and deliver Fe-S clusters to enzymes requiring them for their function. Research in the Torelli lab is focused on several aspects of Fe-S biosynthesis. First, we are interested in fundamental questions regarding how Fe-S clusters are formed by the biosynthetic machinery. For example, how are the toxic ferrous iron and sulfide ions combined to form nascent clusters? What electronic and structural modifications are required to form different Fe-S cluster species? How does a single biosynthetic pathway load Fe-S clusters into the diverse array of cellular proteins that require their function? Second, one biosynthetic pathway in particular is highly upregulated during oxidative stress and iron starvation. How are the properties of the Fe-S clusters modulated during formation by this pathway to resist deleterious conditions? What specific protein:cluster interactions are required for biosynthesis during oxidative stress? Why haven’t other Fe-S biosynthetic pathways evolved similarly robust function that is less sensitive to adverse conditions? Third, Fe-S clusters have chemical versatility and are natural chromophores. We are looking into novel applications of Fe-S proteins in areas of energy conversion and bioremediation. Techniques employed in the Torelli lab include a variety of biophysical methods, especially X-ray crystallography. Other primary methods include electrochemical and spectroscopic analyses that are being performed in collaborations. Biophysical characterization (e.g. dynamic light scattering, size exclusion chromatography, ultracentrifugation) is also a focus, as well as standard molecular biology and microbiology methods used for bacterial overexpression and growth fitness trials. E-mail: torelli@bgsu.edu Phone: 419-372-8744 R. Marshall Wilson Research Professor of Chemistry Ph.D., Massachusetts Institute of Technology, 1965 Our research interests are directed towards the development of reagents for the photochemical analysis and manipulation of biological systems. These include: The development of new reagents for the photochemical cross-linking of nucleic acids, primarily RNA, with proteins. The development of new reagents for the photochemical cleavage of nucleic acids, primarily RNA. The development of the aforementioned two techniques to study the interactions between nucleic acids and proteins using mass spectrometry to obtain detailed structural information about the nature of these interactions. E-mail: rmw@bgsu.eu Phone: 419-372-2035 Zhaohui Xu Assistant Professor of Biological Sciences Ph.D., Huazhong Agricultural University (Wuhan, China), 2000 Our current focus is the genetics and applications of hyperthermophilic bacteria that can convert agricultural or industrial wastes to bioenergy products and/or green chemicals. Molecular biological, biochemical, and bioinformatical methods are being used to investigate the genetics and physiology of these bacteria. Genetic engineering approaches are developed to customize these species to our specific needs. We are also interested in understanding the biological functions of the photoreceptor Anabaena sensory rhodopsin and its transducer protein. E-Mail: zxu@bgsu.edu Phone: 419-372-4645 Weidong Yang Assistant Professor of Biological Sciences Ph.D., Fudan University (Shanghai, China), 2002 We are interested in exploring the molecular mechanisms in cells by using single molecule methods and nanotechnology. Currently, we focus on three projects: (1) to unravel the nuclear transport mechanism; (2) to investigate the nuclear envelope disassembly mechanism and (3) to apply the quantum dots (QDs) as bio-probes in the biological systems. Our long-term goal is to set up an advanced biophysical research program, which includes four subdivisions: singlemolecule microscopy imaging, cell biology, spectroscopy and nano-bio-probes. The individual subdivisions can be developed independently or be combined to study challenging research projects if necessary. E-mail: wyang@bgsu.edu Phone: 419-372-8007 Mikhail Zamkov Assistant Professor of Physics Ph.D., Kansas State University, 2003 Our research focuses on the electronic, chemical and optical properties of semiconductor nanostructures (quantum dots) and hybrid nanoscale materials prepared by means of colloidal syntheses. Such nanoparticles can be chemically manipulated like large molecules and can be coupled to each other or can be incorporated into different types of inorganic or organic matrices. Specifically, experimental work in our group addresses four major areas: (1) synthesis and characterization of novel nanoscale materials, (2) elucidation of their fundamental optoelectronic properties, (3) design and demonstration of functional nanoscale devices and integrated nanosystems, and (4) exploration of the interface/communication between biological systems and nanoscale devices. This research is highly interdisciplinary, involving concepts and techniques from biology, chemistry, physics and the engineering sciences to achieve our goals. E-Mail: zamkovm@bgsu.edu Phone: 419-372-0264 For more information about any of the above research, please contact: Center for Photochemical Sciences Bowling Green State University Bowling Green, OH 43403 U.S.A. Phone: 419-372-2033 Fax: 419-372-0366