Chemistry / Biochemistry
Contact
Department Chair:
Rebecca Whelan

Administrative Assistant:
Patricia West, A263

Department Email:


Phone: (440) 775-8300
Fax: (440) 775-6682

Location:
Science Center A263
119 Woodland St.
Oberlin, OH, 44074

Office Hours: 8:30-noon 1:00-5:00pm

Winter Term 2011

Winter Term 2011

Erin  Adair  '14   Albuquerque, NM      Advisor:  Jesse Rowsell

Research Project:  Molecular Graphic Design

Description:  My winter term project will involve the preparation of animated instructional materials for chemical concepts. I will be combining widely-used animation software (Adobe Flash, Powerpoint) with molecular rendering packages (Mercury, CrystalMaker) to breathe life into the static images found in textbooks.

Other Interests:  Reading, drawing, baking

 

Vincent Alessi  '11   Ann Arbor, MI      Advisor:  Norman Craig

Honors Project:  Synthesis of Isotopomers of cis- and trans-Hexatriene and High-Resolution Molecular Spectroscopy

Description:  Deuterium and 13C isotopomers of the cis and trans isomers of 1,3,5-hexatriene, which are early members of the biologically important polyene series, are being synthesized, and ground state rotational constants are being found from the analysis of C-type bands in the high-resolution infrared spectra of the trans isomer and from microwave spectra for the cis isomer.  From rotational constants and quantum chemical calculations, semi-experimental equilibrium structures will be found with the goal of assessing the structural consequences of pi-electron delocalization at a resolution of 0.001 Å.  To date the 1,1-d2, trans-1-d1, and cis-1-d1 and the 1-13C1 isotopomers have been prepared.  A similar synthetic path should yield the 2-d1 species; new methods should give the other isotopomers. 

Other Interests:  Inventing stuff, art, yoga, innovation-based business, camping/hiking, biking, traveling. 

 

Jordan Attwood  '14   Cheshire, CT      Advisor:  William Fuchsman

Research Project:  Qualitative Tests for Reducing Sugars

Description:  We are comparing the reactions of four oxidizing agents (Ag(I) and Cu(II) in three different environments) with reducing sugars that have different structures.  All four types of reactions are qualitative tests that are reported to produce precipitates in the presence of reducing sugars but not in the presence of nonreducing sugars.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

Other Interests:  Is on the varsity Dive team and likes to play volleyball.

 

Amy Austin  '11   Litchfield, CT      Advisor:  Rebecca Whelan and Mary Garvin

Honors in Biology Project:  Characterization of the uropygial secretions of house sparrows, European starlings, and American robins

Description:  Culex pipiens, a mosquito that serves as the primary vector for West Nile virus in the eastern United States, have been shown to have species specific preferences when feeding on birds. When given the opportunity to choose from an American robin, house sparrow, or European starling, Culex will choose the robin. There are also demonstrated preferences in terms of age in Culex feeding patterns. The objective of this research is to determine the volatile and semivolatile chemical constituents of the uropygial secretions from these three species of bird. It is beginning to be understood that the uropygial secretion’s volatile and semivolatile compounds may serve as chemical signals. This study will investigate that particular phenomenon in the context of the feeding patterns of an important disease vector.  

Other Interests:  Hiking, beading and jewelry making, reading science-fiction and fantasy.

 

Eliot Bixby  '13   Portland, OR      Advisor:  Sean Decatur

Research Project:  Mechanism of γ-D-crystallin aggregation

Description:  γ-D-crystallin is a dimeric protein which belongs to a family of proteins found in the lens of the eye called crystallins. Because mature lens cells lack nuclei, and to properly focus light these proteins must exist in extremely high concentrations without aggregating, crystallins are exceptionally stable. However, when we induce aggregation of γ-D-crystallin, it forms amyloid fibrils similar in structure to those implicated in Parkinson's, Alzheimer's and many other neurodegenerative diseases. By isotope labeling subunits of the protein, and leaving others unlabeled, we can study in more detail changes in the secondary and tertiary structure of the protein as it aggregates. To do this we use Fourier Transform Infared Spectroscopy (FTIR) as well as an emerging technology known as 2 Dimensional FTIR (2D-IR) which is used by our collaborating lab at the University of Wisconsin Madison. Hopefully, by labeling different parts of the protein, varying the conditions which induce aggregation, and studying different aggregation-prone mutants, we can shed some light on the early formation of amyloid fibrils.  

Other Interests:  Cello, computer science, baking

 

Joseph Chang  '11   San Francisco, CA      Advisor:  William Fuchsman

Research Project:  Oxidation of Reducing Sugars by Ferricyanide Ions

Description:  I am comparing the reactions of ferricyanide ions with reducing sugars that have different structures.  Results from this quantitative test for reducing sugars can provide evidence for both the relative sensitivity of the test for different sugars and also the stoichiometry of the reaction.  I hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

 

Matthew Chaves  '11   Holliston, MA      Advisor:  Jesse Rowsell

Honors Project:  Semiconducting Microporous Coordination Frameworks

Description:  Coordination frameworks are currently receiving an enormous amount of attention for their potential applications in the fields of renewable energy and greenhouse gas sequestration. Tens of thousands of new crystalline structures have been reported in the past decade, some displaying record-breaking pore volumes that have been confirmed experimentally through gas adsorption measurements. It has been proposed that such materials could also be employed in small molecule sensors, but only a handful of materials have been shown to demonstrate electronic, optical or magnetic responses to adsorptives.   As a continuation of my honors project, I am examining evidence for semiconductivity in a cobalt(II) carboxylate framework that is sensitive to adsorbed water. This material is among a family of isostructural frameworks, in which none of the other members display this property. We hypothesize that solid solutions (i.e. mixed cation frameworks) will demonstrate varying band gaps based on composition, allowing control of the material’s response to gas molecules of interest. To test this hypothesis, I am exploring synthetic methods for preparing Mg-Co, Zn-Co and Ni-Co frameworks. The as-synthesized and solvent-free materials will be characterized by a battery of techniques, including powder X-ray diffraction, infrared and visible spectroscopy, thermogravimetric analysis, and atomic absorption spectroscopy.

Other interests: Brazilian Jiu Jitsu, swing dancing, cooking.

 

Charlie Cohen  '14   Pittsburgh, PA      Advisor:  William Fuchsman

Research Project:  Qualitative Tests for Reducing Sugars

Description:  We are comparing the reactions of four oxidizing agents (Ag(I) and Cu(II) in three different environments) with reducing sugars that have different structures.  All four types of reactions are qualitative tests that are reported to produce precipitates in the presence of reducing sugars but not in the presence of nonreducing sugars.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

Other Interests:  Reading and writing fantasy, video games, dungeons and dragons, playing guitar

 

Adam Darer  '12   Chestnut Ridge, NY      Advisor:  William Fuchsman

Research Project:  Qualitative Tests for Reducing Sugars

Description:  We are comparing the reactions of four oxidizing agents (Ag(I) and Cu(II) in three different environments) with reducing sugars that have different structures.  All four types of reactions are qualitative tests that are reported to produce precipitates in the presence of reducing sugars but not in the presence of nonreducing sugars.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

Other Interests:  Table Tennis, Playing Jazz Saxophone, Dabbling at the piano, Hiking, Canoeing, Beekeeping, and reading.

 

Clay Easterday  '11    Chardon, OH      Advisor:  Catherine Oertel

Honors Project:  Studies of Reversible Dehydration of Basic Lead Carboxylates

Description:  Basic lead acetate, Pb3O2(CH3COO)2·0.5H2O, is a compound that forms as a corrosion product when lead-based objects such as organ pipes are exposed to acetic acid.  In our laboratory, we have recently crystallized this compound using hydrothermal synthesis and determined its three-dimensional structure.  Use of variable-temperature powder X-ray diffraction showed that the compound undergoes rapid, reversible dehydration upon heating or exposure to vacuum.  A full understanding of the interaction of this compound with the atmosphere is important in establishing its role in the corrosion process and in considering storage or exchange of solvents within the structure.  Goals of this year’s work include determination of the structure of the dehydrated form of basic lead acetate; characterization of the dehydration behavior of basic lead maleate hydrate, a related compound that appears in the literature; and exploration of hydrothermal synthesis of additional basic lead carboxylates.

Other Interests:  Biking, clouds, hiking, climbing trees, reading, poor attempts at dancing, scanning electron microscopy, spreadsheets.

 

Rachel Eaton  '13   Portland, OR      Advisor:  Albert Matlin

Research Project:  Development of an Amine-Catalyzed Nazarov Cyclizatio

Description:  The Nazarov cyclization of cross-conjugated dienones (e.g. divinyl ketones) produces cyclopentenes from acyclic precursors.  Over the past several years this reaction has found wide use in the synthesis of natural products.  This project is investigating the ability of amines to catalyze the Nazarov reaction with the long-term objective of developing an enantio-selective variant using a chiral amine catalyst.

Other Interests:  Oldies (like movies and music), Goodies (like chocolate), and general merriment of life.

 

Micah Ellowitz  '12   El Passo, TX      Advisor:  Jason Belitsky

Research Project:  Pollutant-Binding Melanin-Based Coatings

Description:  Research in the Belitsky lab focuses on synthetic analogs of eumelanin, the black to brown pigment in humans, and on their potential as water purification agents.  Much of our previous work has targeted heavy metals, especially lead.  This Winter Term we are investigating the binding of organic compounds to melanin-based coatings using newly developed assays.  Targets include dyes and pollutants such as poly-chlorinated biphenyls (PCBs).  This work was inspired and enabled by the facile synthesis of pollutant model compounds using palladium-catalyzed chemistry, the subject of this year’s Nobel Prize in Chemistry.  We are also using related chemistry to synthesize inhibitors of melanin formation, for potential therapeutic applications. 

Other Interests:  Backpacking, squash, eating chem office candy, turning assignments in late, sleeping on couches, hanging with the gorgeous Erin Alcorn.

 

Hannah Fuson  '11   Granville, OH      Advisor:  Manish Mehta

Honors Project:  Determination of Chemical Shift Tensor Orientation of Small Peptides Using Rotational Echo Double Resonance and Single Crystal NMR

Description:  Complex niobium and tantalum oxides are useful as photocatalysts for processes including water-splitting.  A new niobate, K2Nb2O6, and its tantalum analogue, K2Ta2O6, have recently been prepared in our laboratory using hydrothermal reactions.  These compounds fall into the family of compounds known as defect pyrochlores, with the general stoichiometry A2M2O6.  Each is made up of a strongly bound [M2O6]2- network associated with loosely bound, exchangeable K+ ions.  Using ion-exchange reactions, we are replacing K+ with cations including Na+, Sn2+, and Mn2+, accessing new phases that cannot be made using high-temperature or hydrothermal methods.  The new compounds are being characterized using powder X-ray diffraction, SEM-EDS, UV-Vis spectroscopy, and thermal analysis.

Other Interests:  Rock climbing, hiking, kayaking, traveling, baking, playing cello and piano, chamber music, mountains, roller coasters, and caffeinating.

 

Joshua Greenfield  '11   Toledo, OH      Advisor:  Catherine Oertel

Honors Project:  Ion-Exchange Synthesis of Complex Niobium and Tantalum Oxides

Description:  Complex niobium and tantalum oxides are useful as photocatalysts for processes including water-splitting.  A new niobate, K2Nb2O6, and its tantalum analogue, K2Ta2O6, have recently been prepared in our laboratory using hydrothermal reactions.  These compounds fall into the family of compounds known as defect pyrochlores, with the general stoichiometry A2M2O6.  Each is made up of a strongly bound [M2O6]2- network associated with loosely bound, exchangeable K+ ions.  Using ion-exchange reactions, we are replacing K+ with cations including Na+, Sn2+, and Mn2+, accessing new phases that cannot be made using high-temperature or hydrothermal methods.  The new compounds are being characterized using powder X-ray diffraction, SEM-EDS, UV-Vis spectroscopy, and thermal analysis.   

Other Interests:  Loves circus arts, birdwatching/nature hiking, and photography

 

Alex Guevara  '14   West Nyack, NY      Advisor:  Catherine Oertel

Research Project:  Art and Chemistry of Pigments

Description:  Pigments are colored, insoluble chemical compounds that are suspended in oil- or water-based binders for application to surfaces.  Most have extended solid-state structures and can be prepared using solution or high-temperature methods.  We are using the blue compound Cu(NH3)4SO4·nH2O (familiar to many students who have synthesized it in Chem 101 or 103) and preparing additional pigments including Mn3+-doped InYO3.  The compounds are being characterized through powder X-ray diffraction.  Using skills learned in the art course “Introduction to Oil Painting,” Alex is preparing paints with these pigments and comparing their behavior on canvas to one another and to commercially available pigments.

Other Interests:  Fencing, drawing/painting, playing guitar, tennis, table tennis

 

Joe Hamilton  '12   Apollo, PA      Advisor:  Albert Matlin

Research Project:  Development of an Amine-Catalyzed Nazarov Cyclizatio

Description:  The Nazarov cyclization of cross-conjugated dienones (e.g. divinyl ketones) produces cyclopentenes from acyclic precursors.  Over the past several years this reaction has found wide use in the synthesis of natural products.  This project is investigating the ability of amines to catalyze the Nazarov reaction with the long-term objective of developing an enantio-selective variant using a chiral amine catalyst.

Other Interests:  I enjoy hiking, biking, watching movies, and cooking

 

Eric Hernandez  '11   Lubbock, TX      Advisor:  Michael Nee

Research Project:  Synthesis of Organic-Inorganic Hybrid Materials Based on TACN

Description:  New materials are being prepared that incorporate an organic portion, 1,4,7-triazacyclononane (TACN), as part of a silica framework. It is hoped the new materials will have a high surface area and have mesopores. These new materials may have interesting and new properties and be useful as hetereogeneous catalysts or chromatograghic supports.

 

Kevin Hu  '11   New York, NY      Advisor:  Rebecca Whelan

Honors Project:  Development of an ELISA for the peptide epitopes of ovarian cancer biomarker CA125

Description:  The ovarian cancer biomarker CA125 is an extremely large and complex protein, comprising dozens of smaller repeated domains that serve as the epitopes for recognition by antibodies. Recently the Whelan lab succeeded in synthesizing the most frequently occurring peptide epitope of CA125 and several important sequence variants. Structural characterization by infrared spectroscopy revealed that extent of aggregated beta-sheet formation was depending upon a single amino acid substitution (proline to serine in position 8). The objective of this study is to develop an enzyme-linked immunoassay to determine the affinity of these synthetic peptide epitopes for monoclonal antibodies with affinity for CA125 as it is found in serum. We are particularly interested in learning whether differences in antibody affinity correlate with previously described differences in structure. 

Other Interests:  Triathlon, Obertones (a cappella), Poetry, Etymology, Entomology, Etymology and Entomology, Medical Ethics, Swing Dance.

 

Benjamin Jakubowski  '11   St. Cloud, MN     Advisor:  Rebecca Whelan

Honors Project:  Characterization of the nonvolatile components of gray catbird uropygial secretions

Description:  This project is part of an ongoing collaboration with Mary Garvin in the Oberlin College Biology Department. The uropygial secretions of some bird species contain compounds ranging from the highly volatile to the extremely nonvolatile. Birds apply the secretions to their feathers during preening. The volatile and semivolatile compounds are hypothesized to serve as chemical signals, whereas the nonvolatiles likely function in maintaining and waterproofing plumage and may also regulate the release of the more volatile constituents. Previous collaborative work between the Whelan and Garvin labs identified a set of volatile and semivolatile compounds in the uropygial secretions of the gray catbird and also established that the levels of these compounds vary with age of the bird and with season/location. The objective of the current research is to characterize the nonvolatile compounds in gray catbird uropygial secretions. To accomplish this, we are using a gas chromatography-mass spectrometry to analyze secretion samples collected from free-ranging catbirds during summer 2010.

Other Interests:  I enjoy playing guitar, running, and porch-sitting.

 

Nathaniel Kadunce  '11   Beaver, PA      Advisor:  Jason Belitsky

Honors Project:  Synthesis of Indole Oligomers Related to Melanin

Description:  Compared to other biochemical entities that are well known to the general public, such as DNA, proteins, carbohydrates, much less is known is about the fundamental biochemistry of melanins.  Even the most basic details, such as the chemical structures of melanins, are uncertain.  Eumelanin, the black to brown pigment is humans, is a nano-structured assembly of dihydroxyindole oligomers.  This Winter Term we will be using palladium-catalyzed chemical reactions (the subject of this year’s Nobel Prize in Chemistry) and other metal-mediated reactions to construct indole oligomers as synthetic model compounds to understand eumelanin at the level of its individual components. 

Other Interests:  I like to play tennis, cook, hang out with people, read, and drink coffee

 

Colin Kelly  '13   Redmond, WA      Advisor:  Michael Nee

Research Project:  Amylose-CB[5] Studies

Description:  The interaction of the smallest known cucurbituril, CB[5], with amylose is being studied. The next two larger sized cucurbiturils, CB[6] and CB[7], form complexes with amylose. However, CB[8] does not bind to amylose. The size discrimination of amylose in binding cucurbiturils will be tested

Other Interests:  I enjoy playing music, watching south park, and hanging out with friends.

 

Simone Koster  '11   New York (NYC and/or Scarsdale)     

Advisor:  William Fuchsman

Honors Project:  Oxidation of Reducing Sugars by Dinitrosalicylate (DNS) Ions

Description:  We are comparing the reactions of DNS ions with reducing sugars that have different structures.  We are obtaining evidence about the stoichiometry of the reactions.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

Other Interests:  Horseback riding, baking, swimming, playing 'cello.

 

Zixin Lu  '13    Suzhou China      Advisor:  Catherine Oertel

Research Project:  Experiment Development:  Synthesis of Copper Inorganic-Organic Network Compounds

Description: Inorganic-organic network compounds, in which ditopic organic ligands form bridges between metal centers, have been the object of widespread study because of their structural diversity and applications in gas storage, sensing, and catalysis.  With the goal of developing a laboratory experiment for use in Chem 103 or Chem 213, we are using room-temperature and hydrothermal solution syntheses to prepare network compounds including either Cu+ or Cu2+ and bridging 4,4'-bipyridine ligands.  Such compounds have been previously reported in the literature, and adaptation for use in courses includes evaluating the feasibility and reproducibility of their syntheses.  We are also characterizing products using powder X-ray diffraction, UV-Vis spectroscopy, and thermogravimetric analysis. 

Other Interests:  Concerts, playing piano and eating Chinese food

 

Gordan MacCallum  '11   Buffalo, NY      Advisor:  Michael Nee

Research Project:  Synthesis of Organic-Inorganic Hybrid Materials Based on Porphyrins

Description:  New materials are being prepared that incorporate an organic portion, meso-tetraphenylporphyrin, as part of a silica framework. It is hoped the new materials will have a high surface area and have mesopores. These new materials may have interesting and new properties and be useful as hetereogeneous catalysts or chromatograghic supports.

Other Interests:  Adult swim, Hip Hop, Science!, The Daily Show, Food     (cooking, eating, etc)

 

Dimitri Macris  '12   The Woodlands, Texas      Advisor:  Rebecca Whelan

Research Project:  Selection and affinity characterization of a DNA aptamer for the peptide epitope of CA125

Description:  The ovarian cancer biomarker CA125 is an extremely large and complex protein, comprising dozens of smaller repeated domains that serve as the epitopes for recognition by antibodies. Recently the Whelan lab succeeded in synthesizing the most frequently occurring peptide epitope of CA125 and several important sequence variants. The objective of this research is to use these synthetic peptides as targets in the process of aptamer selection. Aptamers are single-stranded nucleic acid molecules chosen out of a large random pool of sequences by an iterative selection process in which the pool of DNA is allowed to interact with a protein or peptide target, then the DNA molecules that bind well to the target are isolated from those that do not. We are using capillary electrophoresis and laser-induced fluorescence to accomplish the selection process, and in between selection rounds, DNA is amplified by polymerase chain reaction, purified, and subjected to a single-stranding procedure to give a pool that is enriched with good binders. The final result will be a unique DNA sequence that binds with very high affinity to our peptide target. This aptamer may then be used to develop new detection methods for the peptide epitopes of CA125. 

Other Interests:  Water Polo, Receiving Massages, Dexter, CMF, The Way Things Work, and Inyang Udo-Inyang

 

Melanie Malinas  '13   Reno, NV      Advisor:  William Fuchsman

Research Project:  Oxidation of Reducing Sugars by Dinitrosalicylate (DNS) Ions

Description:  We are comparing the reactions of DNS ions with reducing sugars that have different structures.  We are obtaining evidence about the stoichiometry of the reactions.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

Other Interests:  Reading, music, performing, playing Scrabble, skiing and watching movies

 

Alison O'Connor  '12   Shaker Heights, OH      Advisor:  Rebecca Whelan

Research Project:  Characterization of alarm odors in chicks

Description:  This project is in collaboration with Julie Hagelin of the Swarthmore College Biology Department. 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 will use solid-phase microextraction and gas chromatography-mass spectrometry to determine and quantify the volatile compounds in these samples.

Other Interests:  Baking vegan goodies, tap dancing, and Joss Whedon shows

 

Laura Rios  '12   El Passo, TX      Advisor:  Robert Q. Thompson

Research Project:  Computational Study of the Relative Energies of Organic Radicals

Description:  Molecular orbital calculations are being used to determine the relative energies of a large series of organic based radicals.  Compounds being looked at include: saturated hydrocarbons (1˚, 2˚ and 3˚ radicals), conjugated radicals (e.g. benzylic and allylic) and compounds containing heteratoms (e.g. B, O, N, S).

Other Interests:  Knitting, reading, obscure Rabelais references, squash, electrons, cooking, nanoparticles"

 

Matthew Segal  '13   Arlington, MA      Advisor:  Jason Belitsky

Research Project:  Boronic Acid Inhibitors of Melanin Formation

Description:  In conjunction with the Belitsky lab’s continuing studies on the structures and functions of melanins, ubiquitous but poorly understood biological pigments, a new project has emerged from our finding a class of compounds (aryl boronic acids) that act as inhibitors of melanin formation by an unusual mechanism.  Such inhibition could have cosmetic, therapeutic, and materials applications.  While most inhibitors of biochemical pathways target particular enzymes, in this case the inhibitors target the substrates by means of reversible covalent bonds.  This Winter Term we will explore the molecular details of this process and develop second-generation inhibitors.

Other Interests:  Playing the banjo, making bread, cooking, and playing tennis

 

Eleanor Spielman-Sun  '14   Menlo Park, CA     

Advisor:  William Fuchsman

Research Project:  Qualitative Tests for Reducing Sugars

Description:  We are comparing the reactions of four oxidizing agents (Ag(I) and Cu(II) in three different environments) with reducing sugars that have different structures.  All four types of reactions are qualitative tests that are reported to produce precipitates in the presence of reducing sugars but not in the presence of nonreducing sugars.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

Other Interests:  Photography, drawing, reading, hiking

 

Petros Svoronos  '13   Gainesville, FL      Advisor:  Norman Craig

Research Project:  Gas Phase Raman Spectra of cis- and trans-1,2-Difluoroethylene; Synthesis of trans,trans-1,4-Difluorobutadiene

Description:  For use in testing advanced code for computing anharmonic and resonance corrections to harmonic vibration frequencies, a colleague in Moscow, Russia asked us to record, for the first time, the gas-phase Raman spectra of cis- and trans-1,2-difluoroethylene.  We used our Fourier transform Raman spectrometer, which has 1064-nm laser excitation, and a much simpler experimental setup than is customary for weak gas-phase spectra.  A second project has been completing the synthesis and purification of trans,trans-1,4-difluorobutadiene for use in high-resolution infrared spectroscopy.  The ultimate goal is obtaining a semi-experimental equilibrium structure of trans,trans-1,4-difluorobutadiene and its two isomers. 

Other Interests:  Reading, listening to music, pretending to be a sloth so I can justify sleeping all the time, and watching movies

 

Yue Tang  '13   Shanghai, China      Advisor:  William Fuchsman

Research Project:  Qualitative Tests for Reducing Sugars

Description:  We are comparing the reactions of four oxidizing agents (Ag(I) and Cu(II) in three different environments) with reducing sugars that have different structures.  All four types of reactions are qualitative tests that are reported to produce precipitates in the presence of reducing sugars but not in the presence of nonreducing sugars.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations.

Other Interests:  Reading and practicing Taichi.

 

Sophia Toraby  '11   Cos Cob, CT      Advisor:  Rebecca Whelan

Honors Project:  Selection of a DNA aptamer with affinity for the peptide epitope of CA125 

Description:  The ovarian cancer biomarker CA125 is an extremely large and complex protein, comprising dozens of smaller repeated domains that serve as the epitopes for recognition by antibodies. Recently the Whelan lab succeeded in synthesizing the most frequently occurring peptide epitope of CA125 and several important sequence variants. The objective of this research is to use these synthetic peptides as targets in the process of aptamer selection. Aptamers are single-stranded nucleic acid molecules chosen out of a large random pool of sequences by an iterative selection process in which the pool of DNA is allowed to interact with a protein or peptide target, then the DNA molecules that bind well to the target are isolated from those that do not. We are using capillary electrophoresis and laser-induced fluorescence to accomplish the selection process, and in between selection rounds, DNA is amplified by polymerase chain reaction, purified, and subjected to a single-stranding procedure to give a pool that is enriched with good binders. The final result will be a unique DNA sequence that binds with very high affinity to our peptide target. This aptamer may then be used to develop new detection methods for the peptide epitopes of CA125. 

Other Interests:  Knitting, singing, dancing, minesweeper, procrastination, skiing, frisbee, sleeping.

 

Herman Van Besien  '11   Chicago, IL.      Advisor:  Norman Craig

Research Project:  Gas Phase Raman Spectra of cis- and trans-1,2-Difluoroethylene; Synthesis of trans,trans-1,4-Difluorobutadiene

Description:  For use in testing advanced code for computing anharmonic and resonance corrections to harmonic vibration frequencies, a colleague in Moscow, Russia asked us to record, for the first time, the gas-phase Raman spectra of cis- and trans-1,2-difluoroethylene.  We used our Fourier transform Raman spectrometer, which has 1064-nm laser excitation, and a much simpler experimental setup than is customary for weak gas-phase spectra.  A second project has been completing the synthesis and purification of trans,trans-1,4-difluorobutadiene for use in high-resolution infrared spectroscopy.  The ultimate goal is obtaining a semi-experimental equilibrium structure of trans,trans-1,4-difluorobutadiene and its two isomers. 

Other Interests:  I enjoy playing the piano and guitar, talking to people, and reading. I am also learning Korean at a rate that will make me fluent by age 50.

 

Alex Watanabe  '14   Honolulu, HI      Advisor:  Drew Meyer

Research Project:  Charge-Transfer Multiplet Calculations used to Analyze Core-hole Electronic States

Description:  The electronic structure of many transition metal complexes often has a profound effect on the chemical properties of the system.  One powerful tool to extract information about the electronic structure of these systems is x-ray spectroscopy.  The high energy of x-ray photons allows the excitation of core electrons in bulk, complex systems with elemental specificity.  The electronic structure of the excited molecular state can depend strongly on the nature of the core-hole, and often, electronic states will be split into a series of states, known as multiplets.  In order to computationally describe the electronic spectra of systems after interaction with x-ray photons, a scheme must be derived that takes the core-hole into account.  Charge-transfer multiplet calculations take into account the interaction of the metal center with a ligand field as well as mixing of several charge transfer states in the presence of a core-hole.

 Other Interests: Playing the violin especially chamber music. I enjoy hanging out with friends.

 

Gabrielle White-Dzuro  '12   Toronto, ON      Advisor:  Catherine Oertel

Research Project:  Synthesis and Diffraction Studies of Basic Lead Carboxylates

Description:  Basic lead acetate, Pb3O2(CH3COO)2·0.5H2O, is a compound that forms as a corrosion product when lead-based objects such as organ pipes are exposed to acetic acid.  In our laboratory, we have recently crystallized this compound using hydrothermal synthesis and determined its three-dimensional structure.  Use of variable-temperature powder X-ray diffraction showed that the compound undergoes rapid, reversible dehydration upon heating or exposure to vacuum.  We are preparing a second basic lead acetate, Pb4O(CH3COO)2·H2O, in polycrystalline form and comparing its dehydration behavior compared to that of Pb3O2(CH3COO)2·0.5H2O.  In addition, we are optimizing collection of powder X-ray diffraction data for Pb3O2(CH3COO)2·0.5H2O and basic lead formate, Pb2O(CHOO)2, to minimize the effects of preferred orientation in collecting high-quality patterns.

Other Interests:  Tennis, baking, swimming.

 

Jaie Woodard  '11   Jackson, MI      Advisor:  Manish Mehta

Research Project:  Computational Studies of Peptide-Solvent Interactions

Description:  Small biological molecules, such as di- and tripeptides, lend themselves well to quantitative computational analysis, as well as experimental investigation. The small tripeptides we are studying are chains of three alanine and/or glycine amino acids. I am using a combination of computational techniques to investigate the secondary structure of these molecules in their solvated state. Molecular dynamics simulations use calculated forces and Newtonian laws of motion to map the trajectories of systems of atoms over periods of nanoseconds or picoseconds.  Ab initio and semiempirical calculations numerically solve the Schrödinger equation, using quantum mechanical principles to calculate various molecular properties. 

Other Interests:  Horn playing, music composition, Wagner operas, Mahler symphonies, physics, math, Bach cello suites, history/philosophy of science, competitive walking, Schubert Lieder, Beethoven piano concerti, movies, women’s gymnastics.

 

Ruijie  Yu  '14   Chendu, Sichuan/Szechuan, China      Advisor:  William Fuchsman

Research Project:  Qualitative Tests for Reducing Sugars

Description:  We are comparing the reactions of four oxidizing agents (Ag(I) and Cu(II) in three different environments) with reducing sugars that have different structures.  All four types of reactions are qualitative tests that are reported to produce precipitates in the presence of reducing sugars but not in the presence of nonreducing sugars.  We hope to obtain information that might distinguish between the generally accepted hypothesis that reducing sugars undergo aldehyde-to-carboxylate oxidations and the alternative hypothesis that reducing sugars undergo carbanion-to-carbocation oxidations. 

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

Research Project:  Synthesis and Characterization of Lanthanide Carboxylate Frameworks for Hydrogen Adsorption Spectroscopy

Description:  Coordination frameworks are currently receiving an enormous amount of attention for their potential applications in the fields of renewable energy and greenhouse gas sequestration. Tens of thousands of new crystalline structures have been reported in the past decade, some displaying record-breaking pore volumes that have been confirmed experimentally through gas adsorption measurements. Despite several years of intense global research, none of these materials exhibits the necessary properties for practical storage of molecular hydrogen, a non-carbonaceous energy carrier that is integral in the transition to renewable energy technologies in the next century. Through an ongoing collaboration with the FitzGerald lab (Department of Physics and Astronomy), we are examining the quantum mechanical behavior of H2 in the pores of solid materials using low temperature FTIR spectroscopy. Results of these studies will supplement guidelines for the design of improved materials through a detailed understanding of the interactions between H2 and surface atoms. I am currently optimizing the synthesis and desolvation processes for an isostructural series of materials assembled from benzene-1,3,5-tricarboxylate and large cations such as Y3+ and the lanthanides. After characterizing the products using powder X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis, we will confirm their porosity using gas adsorption measurements. Promising samples are then poised for analysis by low-temperature diffuse reflectance infrared spectroscopy under a range of hydrogen gas pressures.  

Other Interests:  Photography, cello.