Student Research
 Because most of the chemistry faculty are actively involved in research, any interested student is virtually guaranteed the opportunity to do research; these opportunities range from summer internships as part of the John S. Rogers Summer Science Research Program to a senior honors thesis project. Many of these research projects have culminated in articles published in scientific journals.
Faculty research interests are quite diverse (contaminant remediation with clays and minerals, DNA bending associated with carcinogens, catalysis with metal hydrides, the role of protease enzymes in memory, characterization of heteropolytungstate anions, and silicate melt electrochemistry), so every student should be able to find a project of interest.
Descriptions of student research projects are given in this section; in some cases, more details can be found on the web pages of the faculty member leading the research project. If you have any questions, let us know!
Barbara Balko
balko@lclark.edu
Recent Projects
Barbara Balko
Electron Transfer Reactions at Mineral and Clay Surfaces
Students: Alli Clark
---An Electrochemical Investigation of the Enhanced Reactivity of Clays in Contact with Iron Metal---
Clays and iron metal are each independently capable of reducing a range of contaminants in aqueous solutions. There is a synergistic effect on the rate of reduction, however, when clays are in contact with iron metal. We believe that there are two reasons for this: (i) the presence of clay increases the rate of corrosion of the iron metal to Fe(II) and (ii) the Fe(II) associated with clay is an especially strong reductant. The purpose of this project is to better understand the mechanism behind the iron/clay enhancement with the ultimate goal of improving contaminant remediation processes.
This work is supported by the John S. Rogers Science Research Program at Lewis & Clark College.
---The Effect of Doping with Ti(IV) and Sn(IV) on Oxygen Reduction at Hematite Electrodes---
The association of Fe(II) sites with Fe(III)-containing iron oxides increases the reducing capabilities of these oxides and, thus, can have a significant impact on the biogeochemistry of natural systems and on the continued corrosion of iron structures. Doping, the introduction of impurities, is one way to introduce Fe(II) sites into Fe(III). Because doping occurs naturally, it is important to learn how doping affects the reactivity of Fe(III)-containing oxides. In this project, we prepared hematite (an iron oxide, a-Fe2O3) doped with Sn(IV) and Ti(IV) and compared the reactivity of the doped electrodes toward oxygen reduction. Our results showed that the reactivity of doped hematite towards the reduction of oxygen is primarily determined by the concentration of the dopant rather than by its identity. The increase in reactivity, however, was significantly less than the increase in dopant concentration. This result suggests that catalytic surface Fe(II) sites play an important role in the reduction of oxygen at hematite electrodes.
This project has been completed and has been written up in the Journal of The Electrochemical Society (Balko and Clarkson, Journal of the Electrochemical Society, 148 (2) E85-E91 (2001)). Katie Clarkson, the co-author of the paper, was involved in this project while she was a student at Lewis & Clark; she graduated May 2001. Details on this project are available on my website.
This work was supported by the John S. Rogers Science Research Program at Lewis & Clark College, the Olin Corporation Charitable Trust Award of Research Corporation, and the Camille & Henry Dreyfus Faculty Start-up Grant Program.
---Development of a CD-ROM to Teach Chemistry Within the Context of Environmental Remediation---
We are developing a CD-ROM to introduce students and teachers to the chemistry involved in permeable reactive barriers (PRBs) composed of iron particles. Iron PRB technology, which is currently used to reduce halocarbon contaminants in groundwater, provides an excellent teaching opportunity because it interests most students and because the technology illustrates concepts from several fields of chemistry (namely environmental, organic, physical, electrochemistry, and inorganic), many of which can be discussed at a range of levels. The CD-ROM format makes it possible for users to proceed through the material according to their own abilities and interests and allows us to use various media to illustrate the chemical concepts.
This project has been done in collaboration with Professor Paul Tratnyek and Dr. Tim Johnson at the Oregon Graduate Institute and several Lewis & Clark students: David Severson (class of 1999), Theron Morgan-Brown (class of 2000), and Jonathan Edwards (class of 2000). The development work is essentially completed and we are now making cosmetic modifications to prepare the CD-ROM for distribution. Details on this project are available at this site.
Primary financial support for this project is from the Special Grant Program of the Camille & Henry Dreyfus Fondation, Inc.
Jim Duncan
Physical Organic Chemistry
Students: Marie Spong
PAHs, polycyclic aromatic hydrogens, are a type of toxin found in cigarette smoke. One particular type of PAH is called BP, or benzo[a]pyrene. It is metabolized in the body to form a carcinogen known BPDE, which then binds to DNA. In our group, we look at how DNA bends due to these BPDE lesions. If we can understand this phenomenon, we may be able to better understand how this carcinogen acts and find means to prevent it.
We also use molecular modeling and ab initio calculations to predict reaction pathways in particular organic reactions that can then be tested in the laboratory.
Louis Kuo
Biochemistry of RNA Enzymes
Aqueous Organometallic Chemistry
Students: Nicole Morin, David Finnigan, Nicholas Tadros
---The Role of Metal Ions in RNA Enzymes---
Before the 1990’s, the general paradigm in molecular biology was that chemical catalysis belonged to the realm of proteins. However, biochemists at U. Colorado-Boulder and Yale showed that RNA alone can carry out chemical catalysis as well as proteins. For this surprising finding, the 1989 Noble prize was awarded to the discoverers of RNA enzymes, “ribozymes.” In fact, one theory hypothesizes ribozymes may have been the first form of biological catalysis and all subsequent “higher level” of chemical catalysis evolved from RNA. There are six classes of ribozymes, and the class we study is known as the group I ribozymes. They are found throughout the biological kingdom and play an important role in processing (splicing) RNA as it is made from DNA. One important feature about group I ribozymes is that they depend on metal ions for chemical catalysis. We are currently studying this question for one particular ribozyme that I had cloned while on a junior sabbatical at the U. Colorado-Boulder. The full characterization of this ribozyme was done by L&C undergraduates and written up in the journal Biochimica et Biophysica Acta (Leslie Davidson and Stacy Pico, vol. 1489, p.281-292, 1999). In the last two summers, L&C students Nicholas Perera, Shyla Tarpo, and Nicole Morin have found that group I ribozymes derived from phylogenetically distant organisms use a common chemical strategy for accelerating RNA splicing. This strategy employs several magnesium(II) ions, and we are currently studying the fundamental inorganic chemistry for this process.
This work, which is done on collaboration with research chemists at the University of Chicago, was supported by the John S. Rogers Science Research Progarm at Lewis & Clark College, and the Petroleum Research Fund.
---The Application of Organometallic Complexes in Water-based Chemistry---
Organometallic chemistry lies at the interface of organic and inorganic chemistry, and many of these complexes have been used as synthetic tools in polymer and organic synthesis. One of the new areas in organometallic chemistry is applying their rich synthetic capabilities in water. There are many advantages for performing organic transformations in water. For one, water as a solvent is dirt cheap, but the main advantage is that one does not have to work with hazardous solvents that are often flammable. The use of organometallic complexes in water is therefore a form of “green” chemistry, and it offers many environmental benefits for the chemical industry. However, the challenges of such aqueous chemistry is that many organometallic complexes are unstable in water.
In the past seven years we have been studying an organometallic complex, called metallocenes for effecting the degradation of phosphate neurotoxins and for carrying out metal-hydrogen chemistry in water. We have published three papers with L&C undergraduates on hydrolyzing phosphate esters by a metallocene complex; one of these esters was a known pesticide (Sam Kuhn and Dan Ly, in Inorganic Chemistry 1995, 34, 5341-5345; Laurie Barnes in Inorganic Chemistry 1999, 38, 814-817; and Nicholas Perera in Inorganic Chemistry 2000, 39, 2103-2106).
More information on this work is available on Professor Kuo's research page.
The other aqueous organometallic project involves using this metallocene for organic transformations on carbonyl compounds (i.e. ketones/aldehyde) in water. We recently had a paper accepted in the journal Organometallics (Kukui Awan and Clara Hsia, 2001, accepted) that reports a carbonyl to alcohol transformation by this molybdenum-based metallocene in water under very benign conditions (neutral pH and 40oC).
This project is funded by the Petroleum Research Fund and Research Corporation. Major equipment for this work came from a NSF instrumentation grant.
Janis Lochner
Biochemistry
Students: Rosalee Rasmussen and Kate Gessford
Research: Fluorescence microscopy and green fluorescent protein technology is used to study the localization of proteases in hippocampal neurons. The protease we are currently investiating, tissue plasminogen activator, is implicated in Iedrning-related synaptic plasticity.
Bill Randall
Synthesis and Characterization of Heteropolytungstate Anions
Students: Miles Carter
Research: Heteropolytungstate anions (HTAs) catalyze industrial waste degradation, show antitumoral and antiviral activity, act as enzyme inhibitors, coagulate proteins, and precipitate certain organics. In our group, we synthesize and characterize new ruthenium complexes of the heteropolytungstate anion for possible future applications.
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