Departments

Winter Term 2013 Research

Winter Term 2013 Research

Adam Birdsall  '13   From: Roseville, MN     

Advisor:  Matthew Elrod

Honors Project:  Esterification Equilibria and Kinetics of Methacrolein-Derived Species on Secondary Organic Aerosol

Description: Isoprene, 2-methyl-1,3 butadiene, is the most abundant non-methane hydrocarbon present in the atmosphere. This volatile alkene, produced mainly by trees, plays a key role in the formation of secondary organic aerosol (SOA), which is linked to air pollution and climate change mechanisms. One of isoprene’s gas phase oxidation products, methacrolein, apparently undergoes gas phase conversion to a hydroxycarboxylic acid species, which is then observed to undergo esterification reactions on existing SOA. We will synthesize the gas phase precursor and investigate the esterification equilibrium and rate constants for the reactions in model solutions that mimic the composition of SOA using nuclear magnetic resonance analytical methods.  These measurements will allow for a more detailed quantitative modeling of isoprene-derived SOA in the atmosphere.

Other Interests: Devouring large quantities of music, drinking tea, enjoying silent film comedies, playing piano and racquetball (not simultaneously) reading, running.


Dylan Bleier  '15   Ithaca, NY      Advisor:  Matthew Elrod

Research Project:  Reactions of the Oxidation Products of Pinene-Derived Hydrocarbons on Secondary Organic Aerosol

Description:  Biogenic hydrocarbons (such as isoprene and pinene) play a role in both tropospheric ozone and secondary organic aerosol (SOA) formation, and are thus linked to air pollution and global climate change. We are interested in studying the kinetics of reactions of pinene-derived oxidation intermediates that may take place in SOA environments.  These processes are hypothesized to explain the various organic species that are observed in atmospheric SOA. This work will allow for a more detailed quantitative modeling of biogenic-derived SOA in the atmosphere.

Other Interests:  Acoustic and electric guitar; The Beatles; squash, racquetball, and ultimate frisbee; backpacking and outdoor survival; The Stephanie Miller Show and This American Life; The New York Times and The Huffington Post; politics/current events, solar energy production, environmental issues, chemistry, physics.


William Burke  '15   Alpharetta, GA     

Advisor:  Robert Thompson

Research Project:  Ethanol in blood by headspace gas chromatographic analysis

Description: The measurement of ethanol in blood is important to determine whether or not a driver was intoxicated at the time of an accident or roadside stop by a police officer. In the laboratory, the accepted method for ethanol is headspace analysis using gas chromatography. Ethanol vapor is generated from the blood that partly fills a sealed vial, and after equilibrium is reached 500 µL of the headspace (gas) is removed for injection into the chromatograph. The students will develop a manual sampling method for ethanol, optimizing factors such as temperature, time, addition of salt, stirring/shaking, and amount of internal standard (n-propanol). Artificial blood will be created, and the amount of ethanol in that blood will be determined. The final goal is a validated method and experiment for use in a forensic analytical chemistry course.

Other Interests: At Oberlin,the observatory is an adventure in itself on rainy/snowy evenings. Cartoon/Animation/Anime club after the observatory is the cleanest funnest way to spend a Friday night in my experiences here. Can eat eight Stevenson burgers in one sitting. I enjoy Kendal visits.

Yihui Chen  '13   Singapore, Singapore      Advisor:  Norm Craig

Honors Project:  Analysis of the Rotational Structure in High-Resolution Infrared Spectra

Description:  Our primary goal is to obtain accurate equilibrium structures for molecules in which π-electron delocalization plays an important role in modifying the structure. Molecules being studied are trans-hexatriene and the cis,cis and trans,trans isomers of 1,4-difluorobutadiene. Essential to this work is finding rotational constants for a suite of isotopically substituted species, which have been synthesized at Oberlin College. The rotational constants come from the detailed analysis of the rotational structure in high-resolution (0.0015 cm-1), gas-phase infrared spectra, which are recorded at Pacific Northwest National Laboratory. Current work is on the spectra of trans,trans-1,4-difluorobutadiene-1-d1 and trans-hexatriene-3-d1. Pattern-recognition software and other powerful computer programs are essential for finding believable paths of spectral subbands in the exceedingly dense jungle of lines in any band, the first step in the analysis.

Other Interests:  Jesus, education access, the intersection of science and religion, productive unproductivity, (listening to/playing) music, reading eating sleeping.


Lauren Choban  '16   From: Westlake, OH     

Advisor:  Jason Belitsky

Research Project:  Environmental Applications of Melanin-Based Materials Including Human Hair

Description: Melanins are ubiquitous but poorly understood biological pigments, which have fascinating chemical properties that can be mimicked with synthetic analogs and/or directly exploited for environmental applications including binding and sensing heavy metals and organic pollutants.  Our previous work has included synthetic and natural melanin coatings (derived from human hair) as lead-binding agents. This Winter Term we will explore (1) melanin-inspired synthetic materials that change color upon binding metal ions; (2) an aggregation-based assay probing the interactions of organic compounds with synthetic melanin; and (3) develop a second-generation coating derived from human hair that incorporates both melanin and protein components of hair (keratin) for targeting arsenic. 

Other Interests: Swimming, reading and baking


Sean Dembowski  '13   Pasadena, CA      Advisor:  Rebecca Whelan

Honors Project:  Synthesis of Biologically Functionalized Iron Oxide Nanoparticles

Description:  A promising strategy for cancer treatment is focused hyperthermia, in which tumor cells are transiently exposed to high temperatures, promoting their destruction. One way to achieve localized heating involves magnetic nanoparticles with surfaces covered by affinity molecules. Interaction of the affinity molecules with their target (CA125 in our case) immobilizes the nanoparticle onto a cancer cell. Application of an oscillating magnetic field increases the temperature of the nanoparticle by as much as 40˚C, “melting” the cell membrane. Under mild conditions, this melting reversibly perforates the cell, enabling the introduction of drugs or material for gene therapy. With more vigorous heating, cells can be killed outright. In a pilot study, 100% of prostate cancer cells targeted in this way were dead after 7 min in a magnetic field. Non-cancer cells subjected to identical treatment remained viable. Aptamers are only beginning to be used in applications of this sort, and they have yet to be examined in the treatment of ovarian cancer. Our work will demonstrate the use of aptamer-based targeting of ovarian cancer cells by coated magnetic nanoparticles for focused heating and destruction. This project is supported by the National Cancer Institute.

Other Interests:  Track & Field, Taiko Drumming, Swing and Blues Dancing, Juggling


Ethan Dempsey-Whiting  '13    From: Kettering, OH

Advisor:  Robert Thompson

Research Project:  Identification and age of oils in paintings by gas chromatography - mass spectrometry

Description: Our goal is to develop a teaching experiment for analytical chemistry with the focus on an oil painting and whether or not it is genuine based on the drying oil used and its apparent age. The nature and age of the oils in an oil painting can be determined or estimated from analysis of the lipids in the pigment binder. A tiny bit of the paint can be made soluble, treated with reagent to create esters from the fatty acids, and analyzed by gas chromatography - mass spectrometry to reveal the number, type, and relative amounts of fatty acids present. This information can provide a clue as to the original drying oil used, be it linseed oil or walnut oil or other natural oil. The information can also indicate the approximate age of the painting since oxidation products, e.g. dicarboxylic acids from monocarboxylic acids, increase with time.

Joe Duprey  '13   Bainbridge Island, WA      Advisor:  Jesse Rowsell

Research Project:  Method Development in the Synthesis and Characterization of Microporous Copper Carboxylates

Description:  HKUST-1 is a brightly colored microporous material formed from dimeric copper(II) tetracarboxylate clusters. Linking these clusters through trimesate moities leads to the formation of channels within the solid. These channels have the capacity to trap small molecules like alcohols, water and dihydrogen. I am working to develop an efficient way to synthesize HKUST-1 by determining how time, temperature, reaction stoichiometry and crystal seeding affect the crystal growth. To characterize the products, I am employing various forms of crystal structure and compositional analysis, including X-ray diffraction, FT-IR, diffuse reflectance UV-vis, thermogravimetric analysis and solvent exchange. The goal is to find which methods of synthesis and analysis will be most instructive in an inorganic teaching laboratory. 

Other Interests:  Bicycles and Italian Food


Rae Eaton  '13   Portland, OR      Advisor:  Rebecca Whelan

Honors Project:  Selection and Characterization of DNA Aptamers for Ovarian Cancer Biomarker HE4

Description:  DNA aptamers are oligonucleotides that recognize and bind targets of interest. An ongoing focus of the Whelan lab is the selection of aptamers for ovarian cancer biomarkers, with intended applications in novel diagnostic and therapeutic strategies. The aim of this project is to select an aptamer for HE4, a newly discovered ovarian cancer biomarker. HE4 has been found to complement the canonical cancer biomarker (CA125), and on the strength of its potential to detect cases of ovarian cancer missed by the CA125 assay, it was recently approved by the FDA for clinical use. We are using capillary electrophoresis-based systematic evolution of ligands by exponential enrichment (CE-SELEX) to identify DNA oligos with affinity for HE4. This approach has been shown by others to increase the speed and efficiency of the selection process. This work is supported by the National Cancer Institute.

Other Interests:  Tea, Fiber Arts, Bread, Sherlock Holmes, Human Diseases


Henrik Ehrhardt  '13   Oswego, NY      Advisor:  Mike Nee

Honors Project:  TACN-Silica Hybrid Materials

Description:  1,4,7-Triazacyclononane (TACN) is a versatile ligand for a range of metal ions. We are seeking to synthesize mesoporous materials with TACN incorporated within the pores. It is hoped that the manganese(III) complex of this incorporated TACN can act as an oxidation catalyst. We are trying two approaches to incorporating the TACN in mesoporous silica materials. One approach is to prepare mesoporous silica with chloropropyl groups in the pores then bonding the TACN to the propyl groups.

Other Interests: Blues dancing




Aaron Garfinkel  '14    From: San Francisco, CA

Advisor:  Robert Thompson

Research Project:  Ethanol in blood by headspace gas chromatographic analysis

Description: The measurement of ethanol in blood is important to determine whether or not a driver was intoxicated at the time of an accident or roadside stop by a police officer. In the laboratory, the accepted method for ethanol is headspace analysis using gas chromatography. Ethanol vapor is generated from the blood that partly fills a sealed vial, and after equilibrium is reached 500 µL of the headspace (gas) is removed for injection into the chromatograph. The students will develop a manual sampling method for ethanol, optimizing factors such as temperature, time, addition of salt, stirring/shaking, and amount of internal standard (n-propanol). Artificial blood will be created, and the amount of ethanol in that blood will be determined. The final goal is a validated method and experiment for use in a forensic analytical chemistry course.

Other Interests: Lifting things. Climbing things. Looking inside of things.  Also, reading, climbing, drawing and dancing (badly) out of the public eye.

Jessica Hubert  '16   From: Chicago, IL     

Advisor:  Jason Belitsky

Research Project:  Environmental Applications of Melanin-Based Materials Including Human Hair

Description: Melanins are ubiquitous but poorly understood biological pigments, which have fascinating chemical properties that can be mimicked with synthetic analogs and/or directly exploited for environmental applications including binding and sensing heavy metals and organic pollutants.  Our previous work has included synthetic and natural melanin coatings (derived from human hair) as lead-binding agents. This Winter Term we will explore (1) melanin-inspired synthetic materials that change color upon binding metal ions; (2) an aggregation-based assay probing the interactions of organic compounds with synthetic melanin; and (3) develop a second-generation coating derived from human hair that incorporates both melanin and protein components of hair (keratin) for targeting arsenic. 

Other Interests: Ultimate frisbee and reading


Ryan (Ted)  Hunter  '16    From: San Diego, CA

Advisor:  Jason Belitsky

Research Project:  Environmental Applications of Melanin-Based Materials Including Human Hair

Description: Melanins are ubiquitous but poorly understood biological pigments, which have fascinating chemical properties that can be mimicked with synthetic analogs and/or directly exploited for environmental applications including binding and sensing heavy metals and organic pollutants.  Our previous work has included synthetic and natural melanin coatings (derived from human hair) as lead-binding agents. This Winter Term we will explore (1) melanin-inspired synthetic materials that change color upon binding metal ions; (2) an aggregation-based assay probing the interactions of organic compounds with synthetic melanin; and (3) develop a second-generation coating derived from human hair that incorporates both melanin and protein components of hair (keratin) for targeting arsenic. 


Michael Jacobs  '15   Dayton, OH      Advisor:  Matthew Elrod

Research Project:  Gas Phase Oxidation Kinetics and Mechanisms for Atmospherically Relevant Epoxide Intermediates

Description:  Isoprene, 2-methyl-1,3 butadiene, is the most abundant non-methane hydrocarbon present in the atmosphere. This volatile alkene, produced mainly by trees, undergoes gas phase reactions to form epoxide intermediates. The oxidation of isoprene to epoxide intermediates is related to both tropospheric ozone and secondary organic aerosol (SOA) formation, and thus linked to air pollution and global climate change. We are interested in determining the mechanism and rate constants for the reactions of atmospherically relevant isoprene epoxide intermediates with OH radicals. Specifically, we are investigating the daytime OH radical initiated process using our lab's unique turbulent flow chemical ionization mass spectrometer (TF-CIMS).  These measurements will allow a determination of whether gas phase processes dominate the fate of epoxide intermediates, or whether aerosol phase processes.

Other Interests:  Watching the Cincinnati Reds play, reading, and watching movies


Edmund Korley  '16    From: Adfienu,Ghana/Newark, NJ

Advisor:  Jason Belitsky

 Research Project:  Environmental Applications of Melanin-Based Materials Including Human Hair

Description: Melanins are ubiquitous but poorly understood biological pigments, which have fascinating chemical properties that can be mimicked with synthetic analogs and/or directly exploited for environmental applications including binding and sensing heavy metals and organic pollutants.  Our previous work has included synthetic and natural melanin coatings (derived from human hair) as lead-binding agents. This Winter Term we will explore (1) melanin-inspired synthetic materials that change color upon binding metal ions; (2) an aggregation-based assay probing the interactions of organic compounds with synthetic melanin; and (3) develop a second-generation coating derived from human hair that incorporates both melanin and protein components of hair (keratin) for targeting arsenic. 

Other Interests: Traversing nature, serving the disadvantaged, recreational basketball.


Eint Kyi  '15   From: Yangon, Myanmar (Burma)     

Advisor:  Mike Nee

 Research Project:  Functionalized Cucurbiturils

Description: Cucurbiturils are barrel-shaped, cyclic polymers of glycourils connected by methylene bridges. They are useful container molecules and can serve as a host for a wide range of cationic guests. Unfortunately, curcurbiturils are essentially insoluble in organic solvents and only slightly soluble in water. We are synthesizing functionalized cucurbiturils to both increase the solubility of the cucurbiturils and to provide a site for chemically modification of the cucurbituril, such as immobilization to solid supports such as silica gel or attachment of polyethylene glycol chains.

Other Interests: Likes cooking with friends, walking around Oberlin, working in the lab, reading, going to the gym, working for OSWELL



Holden Lai  '15   Hong Kong      Advisor:  Mike Nee

Research Project:  Synthesis of More Water-Soluble Substitiuted Cucurbiturils

Description:  Abstract: Cucurbiturils are macrocyclic barrel-shaped molecules that can act as nanocontainers for guest molecules, especially cationic guests. The low solubility of unsubstituted cucurbiturils limits their utility. Cucurbiturils are relatively unreactive so direct substitution of groups on the cucurbituril is difficult. We are seeking to synthesize more water-soluble cucurbiturils by synthesizing oligomeric precursor molecules that can be closed into substituted cucurbiturils with a substituted glycoluril unit.

Other Interests:  Percussion, Running, Talking, Love Poems


Sophie Lewandowski  '16   From: Readington, NJ     

Advisor:  Jason Belitsky


Research Project:  Environmental Applications of Melanin-Based Materials Including Human Hair

Description: Melanins are ubiquitous but poorly understood biological pigments, which have fascinating chemical properties that can be mimicked with synthetic analogs and/or directly exploited for environmental applications including binding and sensing heavy metals and organic pollutants.  Our previous work has included synthetic and natural melanin coatings (derived from human hair) as lead-binding agents. This Winter Term we will explore (1) melanin-inspired synthetic materials that change color upon binding metal ions; (2) an aggregation-based assay probing the interactions of organic compounds with synthetic melanin; and (3) develop a second-generation coating derived from human hair that incorporates both melanin and protein components of hair (keratin) for targeting arsenic. 

Other Interests: Reading, Zumba, watching "Doctor Who" and going to music concerts on campus.


Molly MacInnes  '13   Albion, MI      Advisor:  Jesse Rowsell

Honors Project:  New Organosulfonate Complexes from Commodity Chemicals for the Assembly of Microporous Frameworks

Description:  The commodity dye intermediates H-Acid and chromotropic acid (both naphthalene derivatives) have potential chelating groups at the 4 and 5 positions, but their coordination chemistries are virtually unexplored. This project focuses on the bonding of these molecules with boron, aluminum, and selected transition metals; the synthesis of these coordination compounds, their structures and physical characteristics. They have the potential for construction of microporous frameworks through sulfonate groups at the 2,7 positions, which can be utilized to extend the bonding of these molecules to polarizable metal ions.

Other Interests:  riding horses and playing my flute


Melanie Malinas  '13   Ventura CA/Reno, NV      Advisor:  Manish Mehta

Honors Project:  Solid-State NMR Detection of Protein Folding Intermediates

Description:  The “folding funnel” theory of protein folding envisions that polypeptides fold on a energy landscape – a three-dimensional map where the horizontal coordinates of a point represent a particular conformation of the polypeptide, and the vertical coordinate represents the free energy of the polypeptide in that conformation – shaped like a rugged funnel, the fully-folded protein at the bottom of the funnel with the lowest energy. The folding protein can thus take many pathways to the bottom of the funnel, and doesn’t have a structurally well-defined single set of intermediates that it passes through. This theory is widely accepted in the protein folding community, yet no funnel has ever been mapped experimentally in more than one dimension. In this project, we aim to learn more about the folding landscape of a small, fast-folding protein known as Trp cage using solid-state NMR methods. In particular, we want to use a “freeze-quench” method whereby a protein solution is heated to denature the protein and is then very rapidly frozen in isopentane before it can refold. This method might capture a transient intermediate or intermediates in the folding landscape of Trp cage.

Other Interests:  Singing, musical theater, playing with cute animals and children, obsessing about Harry Potter, playing Scrabble, skiing, long walks, reading xkcd, spending time with wonderful people, and doing science, of course.


Molly Martorella  '14    From: Winchendon, MA

Advisor:  Mike Nee

Research Project:  TACN-Silica Hybrid Materials

Description: 1,4,7-Triazacyclononane (TACN) is a versatile ligand for a range of metal ions. We are seeking to synthesize mesoporous materials with TACN incorporated within the pores. It is hoped that the manganese(III) complex of this incorporated TACN can act as an oxidation catalyst. We are trying two approaches to incorporating the TACN in mesoporous silica materials. One approach is to synthesize TACN with three propyltrialkoxysilane "arms" then combining that with tetraalkoxylsilane in the presence of a polymeric template.

Other Interests: Playing on swings, watching food network, drinking coffee.


Carl Mitchell  '14   From: Princeton, NJ     

Advisor:  Mike Nee

Research Project:  TACN-Silica Hybrid Materials

Description: 1,4,7-Triazacyclononane (TACN) is a versatile ligand for a range of metal ions. We are seeking to synthesize mesoporous materials with TACN incorporated within the pores. It is hoped that the manganese(III) complex of this incorporated TACN can act as an oxidation catalyst. We are trying two approaches to incorporating the TACN in mesoporous silica materials. One approach is to synthesize TACN with three propyltrialkoxysilane "arms" then combining that with tetraalkoxylsilane in the presence of a polymeric template.


Rachel Nesnevich  '16    From: Chicago, IL

Advisor:  Jason Belitsky

Research Project:  Environmental Applications of Melanin-Based Materials Including Human Hair

Description: Melanins are ubiquitous but poorly understood biological pigments, which have fascinating chemical properties that can be mimicked with synthetic analogs and/or directly exploited for environmental applications including binding and sensing heavy metals and organic pollutants.  Our previous work has included synthetic and natural melanin coatings (derived from human hair) as lead-binding agents. This Winter Term we will explore (1) melanin-inspired synthetic materials that change color upon binding metal ions; (2) an aggregation-based assay probing the interactions of organic compounds with synthetic melanin; and (3) develop a second-generation coating derived from human hair that incorporates both melanin and protein components of hair (keratin) for targeting arsenic. 

Other Interests: Dance, Yoga


Conor Narovec  '15   From: Frazeysburg, OH    

Advisor:  Rebecca Whelan

Research Project:  Understanding the toxic and carcinogenic properties of cadmium

Description: This project is an ongoing collaboration with Professor Mary Garvin of the Oberlin College Biology Department. A cancer cluster is an aggregation of cancer cases in a particular population at a frequency beyond that predicated by chance, given the expected frequency of cancer for that region. In the cancer cluster that has been identified in Clyde, Ohio, a small rural community in northwestern Ohio, incidence of childhood cancer is statistically higher than would be predicted in that particular population by chance. Between 1996 and 2011, 36 cases of childhood cancer were reported within the cluster area, having a radius of 6.7 miles. This childhood cancer rate is nearly double, and statistically significantly higher than, that which would be predicted by chance alone. Since Summer 2012 Professor Garvin and her students have been collecting core samples from trees located in the Clyde cancer cluster area and examining these samples by inductively coupled plasma mass spectrometry (ICP-MS; analyses done in collaboration with environmental geochemist Johan Schijf at University of Maryland.) Tree ring analysis, or dendrochronology, is used to gain insight on chemicals present in the environment in the past. ICP-MS analyses reveal unusually high levels of cadmium, a toxic metal, in trees in the Clyde cancer cluster. We are engaging in an extensive literature-based research project on what is currently known about cadmium in the environment and its toxic and carcinogenic properties.

Christina Perez-Tineo  '13         Advisor:  Rebecca Whelan

Research Project:  Selection of DNA Aptamers for the Peptide Epitope of Ovarian Cancer Biomarker CA125

Description:  The selective detection of biomolecules in serum is an important tool for basic research and clinical applications. Traditionally, such assays have relied on antibody molecules as the basis of detection. In this project we will explore a relatively new class of affinity molecules—aptamers—and develop analytical assays that exploit their unique advantages. Aptamers are single-stranded nucleic acid molecules with recognition ability comparable to antibodies. The process of aptamer selection begins with a large random pool of oligonucleotides. The oligos are allowed to interact with the target protein of interest, and those that bind well to the target are separated from those that do not. Good binders are amplified by polymerase chain reaction, and the cycle of selection and amplification continues until the pool converges on a small number of excellent binders. This year, we will continue to work on the selection a DNA aptamer that recognizes a peptide that appears many times in CA 125, a protein that is widely used as an ovarian cancer biomarker. Capillary electrophoresis is used to separate and collect the population of good binders. This work is supported by the National Cancer Institute.

Other Interests:  Likes to read, knit and play La Cross


Eric Romani  '15    From: Lawndale, CA

Advisor:  Bill Fuchsman

Research Project:  I am helping to develop a new spectrophotometric assay for the ubiquitous biological oxidizing agents NAD and NADP.  Unlike currently available assays, the new assay works in the presence of large amounts of of the biological reducing agent NADH.






Jamie Shallcross  '14   From: Metuchen, NJ     

Advisor:  Rebecca Whelan

Research Project:  Computational modeling of a peptide domain from an ovarian cancer biomarker

Description: CA125 is an important biomarker, widely used in the diagnosis and monitoring of ovarian cancer. Recent structural elucidation of the protein revealed that it contains a large number of tandem repeat units, each 156 amino acids long, and within that repeat domain is a highly conserved 21-mer bounded on each end by cysteine residues. All known antibodies with affinity for CA125 bind to one of two unique sites within this 21-mer, suggesting that this relatively simple peptide could serve as a mimic for the intact protein during the development of CA125 assays. Previous efforts in the Whelan lab used solid-phase peptide synthesis to prepare the 21-mer peptide in pure form and characterize its secondary structure. In this project, we will use a molecular modeling toolkit to conduct in silico studies of the secondary structure of the most frequently synthesized 21-mer and several important sequence variants. This initial effort will complement existing spectroscopic data. We will then extend the modeling effort to the full 156-mer peptides, which have not yet been synthesized

Other Interests: I like cooking in OSCA, fiddling with computers, and theater.


Zack Sheldon  '15   From: Washington, District of Columbia       

Advisor:  Mike Nee

Research Project:  Functionalized Cucurbiturils

Description: Cucurbiturils are barrel-shaped, cyclic polymers of glycourils connected by methylene bridges. They are useful container molecules and can serve as a host for a wide range of cationic guests. Unfortunately, curcurbiturils are essentially insoluble in organic solvents and only slightly soluble in water. We are synthesizing functionalized cucurbiturils to both increase the solubility of the cucurbiturils and to provide a site for chemically modification of the cucurbituril, such as immobilization to solid supports such as silica gel or attachment of polyethylene glycol chains.

Shi Shi  '13        Advisor:  Rebecca Whelan

Research Project:  Characterization of Avian Alarm Odors

Description:  This project is a collaboration with Professor Julie Hagelin of Swarthmore College and the University of Alaska-Fairbanks. Little is known about the possible role of alarm odors—chemical messengers emitted by individuals under threat or attack—in bird species, though alarm odors have been characterized in insects and in reptiles. The objective of this work is to examine feces samples from chicks that were subjected to a fear-inducing stimulus and compare these samples to those from birds that were not frightened. We use solid-phase microextraction and gas chromatography-mass spectrometry to determine and quantify the volatile compounds in these samples. (Fun fact: the chemistry of fear was recently featured in the NY Times.)


Greg Tapper  '14    From: Potomac, MD

Advisor:  Jesse Rowsell

Research Project:  Oxidation/Hydrolysis Reactions of Naphthalenesulfonate Dye
Intermediates in Natural Waters

Description: I am researching the reactivity of the industrially important dye intermediate, H-Acid, which is produced in enormous quantities in China and India. The molecule is considered non-toxic, but it forms many colored byproducts upon reaction with water and air. These byproducts are reported to play central roles in wastewater contamination lawsuits within manufacturing communities in India. Reports describing the chemistry of these byproducts appear to be scarce or non-existent in the scientific literature. I am employing UV-vis and HPLC analytical methods to study the kinetics of these reactions with the goal of determining a robust method for purifying and crystallizing the byproducts. This will lead the way to structureelucidations and evaluations of the toxicities of these species.

Other Interests: Reading and rock climbing.


Will Thomas  '15   From: Cleveland, OH     

Advisor:  Mike Nee

Research Project:  Functionalized Cucurbiturils

Description: Cucurbiturils are barrel-shaped, cyclic polymers of glycourils connected by methylene bridges. They are useful container molecules and can serve as a host for a wide range of cationic guests. Unfortunately, curcurbiturils are essentially insoluble in organic solvents and only slightly soluble in water. We are synthesizing functionalized cucurbiturils to both increase the solubility of the cucurbiturils and to provide a site for chemically modification of the cucurbituril, such as immobilization to solid supports such as silica gel or attachment of polyethylene glycol chains.

Other Interests: Likes writing, drawing and playing various instruments.


Tae Kyu (Brian) Uhm  '14   Seoul, Korea      Advisor:  Rebecca Whelan

Research Project:  Selection of DNA Aptamers for the Peptide Epitope of Ovarian Cancer Biomarker CA125

Description:  CA125 is an important biomarker, widely used in the diagnosis and monitoring of ovarian cancer. Recent structural elucidation of the protein revealed that it contains a large number of tandem repeat units, each 156 amino acids long, and within that repeat domain is a highly conserved 21-mer bounded on each end by cysteine residues. All known antibodies with affinity for CA125 bind to one of two unique sites within this 21-mer, suggesting that this relatively simple peptide could serve as a mimic for the intact protein during the development of CA125 assays. Previous efforts in the Whelan lab used solid-phase peptide synthesis to prepare the 21-mer peptide in pure form and characterize its secondary structure. We are now using the peptide as the target in a capillary-electrophoresis-based aptamer selection process, to complement our ongoing work in selecting an aptamer that recognizes intact CA125. This work is supported by the National Cancer Institute

Other Interests:  Making good coffee, baking brownies, DJ-ing, dancing, and playing piano.


Megan Walkenhorst  '13   St. Louis, MO      Advisor:  Robert Thompson

Research Project:  Identification and age of oils in paintings by gas chromatography - mass spectrometry

Description: Our goal is to develop a teaching experiment for analytical chemistry with the focus on an oil painting and whether or not it is genuine based on the drying oil used and its apparent age. The nature and age of the oils in an oil painting can be determined or estimated from analysis of the lipids in the pigment binder. A tiny bit of the paint can be made soluble, treated with reagent to create esters from the fatty acids, and analyzed by gas chromatography - mass spectrometry to reveal the number, type, and relative amounts of fatty acids present. This information can provide a clue as to the original drying oil used, be it linseed oil or walnut oil or other natural oil. The information can also indicate the approximate age of the painting since oxidation products, e.g. dicarboxylic acids from monocarboxylic acids, increase with time.

Other Interests: Watching movies, cooking, reading, and hanging out with friends
Jamie Yelland  '13   Omak, WA      Advisor:  Peter Chivers

Honors Project:  Nickel-ligand Complex Recognition by the E. coli NikA protein.

Description:  Bacteria require transition metals for essential metabolic processes. These metals act as cofactors and must be acquired from the environment. E. coli use the five protein NikABCDE complex to import nickel ions, but the specific form of nickel that was transported has been elusive. We have recently discovered that nickel ions are transported into the cell in the form of a Ni-(L-His)2 complex. I am studying the equilibrium binding of Ni-(L-His)2 and related complexes to the purified NikA protein from E. coli and other bacterial species. I have developed a solution-based assay that will be used to compare the binding affinities of various Ni-ligand complexes with each other and with similar complexes formed by other transition metals to understand the properties of the Ni-(L-His)2 that are important for recognition by NikA

Other Interests:  Cycling, backpacking, fencing, Javanese gamelan, bluegrass and old-time banjo, home-brewing, riding motorcycles, exploring and adventuring.


Ruijie Yu  '14   From: Chendu, Sichuan/Szechuan, China     

Advisor:  Mike Nee

Research Project:  TACN-Silica Hybrid Materials

Description: 1,4,7-Triazacyclononane (TACN) is a versatile ligand for a range of metal ions. We are seeking to synthesize mesoporous materials with TACN incorporated within the pores. It is hoped that the manganese(III) complex of this incorporated TACN can act as an oxidation catalyst. We are trying two approaches to incorporating the TACN in mesoporous silica materials. One approach is to synthesize TACN with three propyltrialkoxysilane "arms" then combining that with tetraalkoxylsilane in the presence of a polymeric template.

Other Interests: Swing dance, anime, sleeping, skiing, laughing, music, green tea, cooking, peanut butter, playing the violin, yoga, and, oh...hanging out with friends!


Cassandra Zentner  '13   Irwin, PA      Advisor:  Jesse Rowsell

Honors Project:  Supramolecular Assembly of Microporous Molecular Crystals

Description:  Molecular crystals rarely sustain microporosity upon evacuation of solvents from the structure’s pores due to the weak interactions that determine the packing.  Recently, we observed a molecular crystal of 1,3,5-tris(4-carboxyphenyl)benzene (tcpb) that retained crystallinity even after the evacuation of the solvent.   We will be functionalizing tcpb with cyano groups and then nitro groups on the central ring, crystallizing the product and comparing it to the prototype tcpb crystal structure.   Another direction of the project is to co-crystallize tcpb with other rigid aromatic acids, namely benzene-1,4-dicarboxylic acid (terephthalic acid) and benzene-1,3,5-tricarboxylic acid.   Products will be characterized using powder x-ray diffraction, thermogravimetric analysis, nuclear magnetic resonance, and infrared spectroscopy. 

Other Interests:  Photography, cello