CHEMISTRY DEPARTMENT

The 2002-2003 year was the second year of our gradual transition to a new curriculum. We’ve now completely restructured our introductory level courses, and will begin the process of making the transition in our upper level curriculum as well in the coming academic year. This has been a challenging and exciting process for us all (learning the new upper level course numbers may present the biggest challenge of all!). We will be very interested to see how the changes we have put into place affect our students’ progression through our major; we’re excited about the prospects and looking forward to getting feedback from our students.

We were very pleased to welcome several new faces to the Chemistry Department this year: Amy Gehring (’94), Dieter Bingemann, and George “Tony” Truran all joined our department this year. Tony Truran’s position in the department is a new one. He is serving as a half-time laboratory instructor in our organic and introductory courses, as well as providing us with some much-needed technical support in our upper level laboratory courses. All three have gotten off to a strong start, and we’re very happy to have them join us. On a sadder note, Assistant Professor Joe Chihade, who was on his AP leave this year, has informed us of his resignation. He will be accepting a tenure-track appointment at Carleton College beginning next year. Chihade has been an active and productive member of our department and he will be missed. We wish him the very best of luck in his future endeavors. Though we are sorry to see Chihade leave, we are grateful for the opportunity to welcome Professor Hodge Markgraf back to our department as a visiting faculty member for one year. Professor Markgraf will teach Organic Chemistry: Intermediate Level (CHEM 251) in fall 2003, and Heterocyclic Chemistry (CHEM 246), a course for which he plans to develop an entirely new lab program, in the spring of next year. We are all excited to welcome him back to the department yet again, and are thrilled that a new crop of students will have the opportunity to learn from such an inspiring and energetic teacher.

This year we continued to participate in the lectureship program under the sponsorship of the Class of 1960 Scholars Program. Three distinguished scientists were invited to campus to meet with our students and present a seminar. Professor Michael Doyle of the University of Arizona, Professor Paul Wender of Stanford University and Professor Katja Lindenberg of the University of California-San Diego were the 1960 Scholar speakers this year. Twelve students were selected by the faculty to be Class of 1960 Scholars during 2003 and to participate in the seminar program which includes: a preliminary meeting with the Scholars and Chemistry Department faculty member to discuss some of the papers of the seminar speaker; attendance at the seminar/discussion; and an opportunity for further discussion with the seminar speaker at an informal reception or dinner. The students selected for 2003-04 are:

Over the course of the year, as is our tradition, a number of awards were presented to chemistry students for outstanding scholarship. Gillian Sowden ’06, Ashleigh Theberg ’06 and Hang “Grace” Song ’06 received the CRC Awards as the outstanding students in CHEM 151, CHEM 153, and CHEM 155 respectively. Anthony Gulati ’04 and Marie-Adele Sorel ’05 were recognized for their achievements in organic chemistry with the Polymer Chemistry Award and the Harold H. Warren Prize respectively. Steven Scroggins ’04 won the American Chemistry Society Analytical Division Award, while the American Chemistry Society Connecticut Valley Section Award for sustained scholastic excellence went to Jason Leith ’03. Finally, the American Institute of Chemists Student Award for outstanding scholastic achievement was awarded to Alison Peet ’03.

At Class Day activities before graduation, the John Sabin Adriance Prize was awarded to Erica C. Dwyer ’03 as the senior chemistry major who maintained the highest rank in all courses offered by the department. In addition, during Class Day, Kudawashe Mutyambizi ’03 was announced as recipient of the Leverett Mears Prize in recognition of outstanding scholastic achievement. The James F. Skinner Prize, for achieving a distinguished record in chemistry and showing promise for teaching and scholarship, was presented to Jennifer L. Roizen ’03.

During the summer of 2003, 35 Williams College chemistry majors were awarded research assistantships to work in the laboratories of departmental faculty. In addition, two students were selected to participate in summer research programs established between our department and the University of Leiden and Rensselaer Polytechnic Institute.

Assistant Professor Dieter Bingemann joined the Chemistry Department in July 2002 after working as an Assistant Scientist at the University of Wisconsin in Madison. During the fall semester, Professor Bingemann taught Concepts of Chemistry: Advanced Section (CHEM 153), and in the spring Physical Chemistry: Structure and Dynamics (CHEM 302), the second semester of the physical chemistry sequence. His research is focused on the dynamics in heterogeneous systems, such as supercooled liquids or polymers. Professor Bingemann started setting up his new lab with the able help of Alison Peet ’03. Alison advanced the lab rapidly from unpacking shipping crates toward the successful observation of a single molecule using fluorescence microscopy. Single molecule spectroscopy will be used as the main tool to investigate heterogeneities in this lab in the future. This work will continue this summer with the help of Noah Capurso ’05 and John Harris ’05, as well as Gerry Lindo ’04 as a thesis student in the upcoming academic year.

In spring of 2003, Professor Bingemann attended the annual meeting of the American Chemical Society in New Orleans. He also presented a “Science Lunch” talk in the spring and acted as a reviewer for the Journal of Chemical Physics.

Professor Raymond Chang Professor Raymond Chang continues to serve on the editorial board of The Chemical Educator. He team-taught Current Topics in Chemistry (CHEM 155), in the fall semester with Professor Peacock-López, who was the organizer of the course.

Assistant Professor Joe Chihade enjoyed a sabbatical year working with Karin Musier-Forsyth at the University of Minnesota continuing his research on aminoacyl-tRNA synthetases. These crucial enzymes ensure the accurate translation of the genetic code by linking amino acids only to tRNAs bearing the correct anticodons. Chihade built on work carried out at Williams by Daniel Clayburgh ’01 and Alix Partnow ’02 on the alanyl-tRNA synthetases that function in mitochondria of humans and the nematode worm C. elegans. These two enzymes, though closely related, use strikingly different strategies to recognize their RNA substrates. In the Musier-Forsyth lab, Chihade has also begun new work on the ability of prolyl-tRNA synthetase to fix its mistakes by removing amino acids from incorrectly charged tRNAs. Back in Williamstown, Kevin Hsueh ’03 worked on a collaborative project with Professor Wendy Raymond in the Biology Department to characterize a protein of unknown function that interacts genetically with the RNA modification enzyme PUS4.

In July, Chihade accompanied Kristen LeChevet ’02 to the Beckman Scholars Symposium in Newport Beach, where she presented her work on site-specific derivatization of RNAs. On a mission to see more than one Newport, Chihade also attended the Gordon Conference on Nucleic Acids at Salve Regina University in Rhode Island in the spring, where he presented a poster on the mitochondrial alanyl-tRNA synthetases.

Assistant Professor Amy Gehring joined the Chemistry Department in July 2002. In the fall, Professor Gehring taught Biochemistry I - Structure and Function of Biological Molecules (CHEM 321), in the spring semester, she taught Enzyme Kinetics and Reaction Mechanisms (CHEM 310), and along with Professor Lovett, team-taught Topics in Biochemistry and Molecular Biology (CHEM 406). Working with honors students Erica Dwyer ’03 and David Lewis ’03, Professor Gehring conducted research directed towards understanding the regulation of differentiation and concurrent antibiotic production in the model bacterial organism Streptomyces coelicolor. Also contributing to this research were Winter Study students Ian McCormick ’03 and Virginia Newman ’04 and research assistant Nadria Gordon ’06. Professor Gehring also began a collaboration with Professor Richardson in the Chemistry Department to isolate and identify a polyketide natural product produced by a mutant strain of S. coelicolor; independent study student Alison Stewart ’03 and research assistant Chris Thom ’06 participated in this work.

In other news, Professor Gehring gave birth to her first child, Olivia, in May 2003. After a few weeks of needed rest, Professor Gehring will be back working with summer research student Ian McCormick ’03.

Professor Lawrence J. Kaplan (<http://www.williams.edu/Chemistry/lkaplan/>) was on a mini-sabbatical in the fall 2002. He was an adjunct visiting professor at the University of Central Florida. He worked with colleagues in the UCF Chemistry Department and the National Center for Forensic Science as well as colleagues at the Florida Department of Law Enforcement. He continues to administer the Center for Workshops in the Chemical Sciences (CWCS; <http://chemistry.gsu.edu/CWCS/>) along with the co-directors. CWCS, established with a $1.85 million grant from the National Science Foundation, sponsors many workshops including Metals in Biology, Chemistry and Art, Environmental Chemistry, Computational and Theoretical Chemistry, Molecular Genetics, Nuclear Magnetic Resonance Spectroscopy and Forensic Science.

The response to Kaplan’s forensic science workshop was so high that he taught two five-day workshops during the summer of 2002 at Williams. The workshops provide an understanding of the application of forensic science to all aspects of undergraduate chemistry instruction. Sixteen participants from colleges and universities as well as community colleges became criminalists for each week. They processed crime scenes and analyzed evidence such as glass and soil, fibers and fingerprints, drugs and alcohol, blood and bullets, and, of course, DNA. This summer, due to overwhelming demand again, Kaplan will be conducting two weeklong sessions of the workshop.

In conjunction with colleagues from a number of departments, Kaplan taught in the introductory course in the new Legal Studies Program. The course Processes of Adjudication (LGST 101) provides a multidisciplinary overview of how disputes are resolved within specific social systems. Kaplan taught the unit on evidence and the admissibility of scientific evidence. In recognition of his contributions to forensic science and forensic science education in particular, Kaplan was promoted to full member in the American Academy of Forensic Sciences at their 55th annual meeting in February.

Professor Charles Lovett continued to serve as Director of the Science Center, Chair of the Science Executive Committee, Chair of the Divisional Research Funding Committee, and Director of the Summer Science Program for Minority Students.

Professor Lovett continued his research on the mechanism of ComK-mediated regulation of the recA gene in the bacterium Bacillus subtilis supported by a $330,000 grant from the National Science Foundation. Last summer Williams College students Pamela Choi ’05, Candice Li ’05, Nosirudeen Quadri ’03, Ila Sheren ’05, and Kamille Williams ’03 worked on this research as full-time research assistants. Also participating in this research and providing invaluable assistance was Thomas O’Gara, now in his fifteenth year as research technician in the Lovett lab. During the academic year, Professor Lovett directed Marsha Lynch ’03 and Kamille Williams ’03 as independent research students and Kuda Mutyambizi ’03 as a senior honor student working on the ComK project. Professor Lovett also directed students Nora Au ’03, Sean Margolis ’04, Nora Matell ’06, and Emily Wasserman ’06 in a winter study research project aimed at characterizing ComK DNA binding mutants.

Last summer, Professor Lovett taught the Chemistry lectures component of the Williams College Summer Science Program for Minority Students. Together with Professor David Richardson, he also supervised the fifth year of science camp for elementary school students and teachers.

In the fall semester, Professor Lovett taught Concepts of Chemistry (CHEM 151), and in the spring semester AIDS: The Disease and Search for a Cure (CHEM 115). He also team-taught, Topics in Biochemistry and Molecular Biology (CHEM 406), with Professor Gehring.

Professor Lovett coordinated the formation of a new curricular program in Bioinformatiics, Genomics, and Proteomics (BiGP) and submitted a proposal to the Sherman Fairchild Foundation for $500,000 to support the development of the program.

During the past year, Professor Lovett served as a reviewer for Molecular Microbiology, the Journal of Bacteriology, and the Journal of Biological Chemistry. He also served as a reviewer for the National Science Foundation Biological Sciences Division, and as a consultant for the Sherman Fairchild Foundation’s Scientific Equipment Grant Program.

Professor emeritus J. Hodge Markgraf supervised the honors thesis of Patrick W. Zimmerman ’03. The focus of their work was a new method of preparing benzocanthinones, which are pentacyclic alkaloids with antibacterial properties. This summer three students will continue this project and extend the methodology to a new route to sampangines, which are naturally-occurring tetracyclic alkaloids with antimalarial and cytotoxic properties. During the spring semester Salem Fevrier ’05 worked part-time on a project related to new analogs of tacrine, a compound used in the treatment of Alzheimer’s disease. Professor Markgraf served as a reviewer for the Journal of Organic Chemistry and Industrial & Engineering Chemistry Research.

Professor Lee Park returned from a semester’s leave in the fall, and took over as chair of the Chemistry Department. In the fall, she taught Inorganic and Organometallic Chemistry (CHEM 305), and in the spring team-taught Instrumental Methods of Analysis (CHEM 304), with Professor Jay Thoman, as well as a laboratory section in Organic Chemistry: Introductory Level (CHEM 156). During Winter Study, she taught Science for Kids with Jenna MacIntire.

Park has enjoyed a fairly productive year in terms of progress on a variety of research projects; she had four students involved in her lab over the year, and anticipated three publications based on work completed during this time. Her research has been supported by a $161,000 NSF-RUI grant. During the summer of 2002, two students, Steve Scroggins ’04 and Teddy McGehee ’05, were the first two students to participate in a newly established collaborative summer research program with faculty in the Chemistry Department at RPI. They worked with Professors Yvonne Akpalu and Chang Ryu for the first several weeks of the summer, then returned to Williams and worked in Park’s lab for another five weeks. In Park’s lab, they worked on synthesizing and characterizing a series of metallomesogenic complexes using a bipyridyl ligand system developed by Carrie Jones ’02 and Susan Fulmer ’02, the previous year. They were able to extend the use of these bipyridyl ligands to Fe(II), Mn(II), and Co(II). A manuscript that includes their summer research efforts is currently in preparation.

Both Steve and Teddy returned to Park’s lab during Winter Study. Steve worked with another Winter Study research student, Beth Landis ’05, on developing an experiment for use in CHEM 305. This project was written up (with Professor Mark Schofield) and has been accepted for publication in The Chemical Educator. Over Winter Study, Teddy worked on characterizing a series of donor-acceptor mesogenic complexes that are the basis of an on-going collaboration with Professor Darren Hamilton at Mt. Holyoke College. This work was presented as a poster at the National ACS meeting in New Orleans, and is the basis of another manuscript that is currently in preparation.

Laurel Hensley ’03, returned to Park’s lab over the academic year as an honors student. Laurel’s work involved wrapping up some of the bipyridyl ligand-related work that she’d been involved in, as well as moving in some new directions. In particular, she began exploring different means of oxidizing/doping the platinum (II) complexes that have been developed in the Park lab, both by chemical means, as well as by more traditional doping approaches involving Co(II) congeners. Laurel’s work was also presented as a poster at the National ACS meeting in New Orleans over spring break.

Park has also kept busy with other professional activities this year. She has continued to serve as a reviewer and panelist for NSF, ACS-PRF, Research Corporation, Benjamin Cummings Publishers. Journal of the American Chemical Society, Chemistry of Materials, and Macromolecules. She has also been involved in an outreach program in which she has been teamed up with two teachers (Bill Dodd and Paul Jebb) from Ticonderoga High School in Fort Ticonderoga, New York.

Professor Peacock-López taught Current Topics in Chemistry (CHEM 155). In addition, during the 2002-03 academic year, Professor Peacock and Mount Greylock Regional High School’s AP chemistry instructor Scott Burdick organized and taught an AP lab experience at Williams College. The AP chemistry students came five times during the year to perform some of the experiments from the Williams introductory chemistry lab program. Lastly, Professor Peacock-López continued his efforts in teaching chemistry to children. This year, Professor Peacock-López gave demonstrations to seven graders from the Springfield, MA, area and helped with the science outreach program that bring fifth graders to the Chemistry Department for hand on demonstrations during National Chemistry Week.

Professor Peacock-López continued his research in complex dynamical chemical and biochemical mechanisms. In work related to the self-replication molecules, he studied a self-replicating mechanism with complementary template and triplex formation. Analyses extended to pattern formation and population dynamics. In the latter case, his lab studied a three-level trophic system with intraspecies interaction, which seemed to stabilize the system diminishing the chance of chaotic trajectories.

Ten years ago Rebeck observed that a mixture of complementary fragments like adenine ribose (AR), biphenyl imide (BI) and thymine yields two self-complementary self-replicating molecules ARBI and ART. Of the two, ART is a better self-replicator than ARBI. Lately Peacock-López studied the dynamic behavior of two competitive reactions that yield self-replicating molecules when the system is kept away from equilibrium. The dynamic properties of self-replicating systems have an impact in understanding the evolution of self-replicating RNA. It has been suggested that prebiotic chemistry created oligonucleotides at random. Of these molecules, some oligonucleotides were able to join nucleotides and perhaps eventually catalyzed their own replication. Recent work by Nicolaou with palindromic oligonucleotides has strengthened this possibility. Somehow, the better self-replicators overcome others and evolve into ribozymes and possibly into self-replicating RNA. However, the role of natural selection is not clearly understood; therefore, he explores the dynamic properties of two competitive self-replicators and the possibility of coexistence or extinction of the two species. It is important to understand the differences in self-replication efficiency and its effects on the system dynamics. His results shed some light on possible mechanisms of self-replicating molecular evolution.

Peacock-López also served as a reviewer for the National Science Foundation and The Chemical Educator.

During the 2002-03 academic year, Professor David Richardson enjoyed his first full year of not being department chair. On the research front, he supervised the work of several students throughout the year. In the summer of 2002, Peta-Gaye Burnett ’03 began her year-long senior honors research working on a collaborative project between Professor Richardson and Professor Dan Lynch’s lab involving the development of a simple, efficient, and sensitive method for the identification and quantification of ceramide samples isolated from plant or animal cell membranes. Also working in the Richardson lab during the summer were Nisha David ’05 and Jude Dumfeh ’04. These students teamed up to continue work on collaboration between Professor Richardson and Professor Hank Art on the isolation of allelopathic agents from “hay-scented fern,” a plant that grows widely in Hopkins Forest. In the fall semester, this project was continued by Marshall Dines ’03, the first student to pursue this work as a senior honors thesis project. Marshall’s very labor-intensive studies were also assisted by Analia Sorribas ’06 an invaluable work study in the Richardson lab throughout the year. Finally, in the fall semester, Alison Stewart ’03 helped the Richardson lab begin a new collaboration with Professor Amy Gehring’s lab. Alison’s project (which was continued in the spring semester by Chris Thom ’06) involved the isolation and structure determination of colored pigments, which are produced by the bacterium Streptomyces coelicolor. During Winter Study Period, Professor Richardson supervised the research of John Harris ’05 pursued in the department’s course Introduction to Research in Organic Chemistry (CHEM 023). John worked on the verification of a synthetic method that is being considered for publication in Organic Syntheses. The method he investigated involved Pd-catalyzed Suzuki coupling of vinyl boronic acids with aryl chlorides. Professor Richardson also supervised the purchase and installation of the department’s new 500 MHz nuclear magnetic resonance spectrometer. Finally, Professor Richardson served as a reviewer for the Journal of Organic Chemistry and for The Chemical Educator.

Professor Richardson’s teaching responsibilities for the year included two courses that he had not had the opportunity to teach for many years. In the fall semester, he taught Organic Chemistry: Intermediate Level (CHEM 251), the second semester introductory organic chemistry course that is part of the department’s new introductory curriculum. In the spring semester, he taught Synthetic Organic Chemistry (CHEM 303/342). In July, he taught the chemistry laboratory portion of the Williams College Summer Science Program for Minority Students and, together with Professor Chip Lovett, he hosted the department’s Summer Science Camp program for local 4th and 5th graders. Professor Richardson also served as chair of the Olmsted Committee.

Assistant Professor Mark Schofield continued his research on the development and synthesis of metalloenzyme mimics while on assistant professor leave last fall. During the summer of 2002, David Chung ’02 continued his thesis work on the development of nickel macrocycles to serve as functional models for the active site of methylcoenzyme M reductase (MCR). This enzyme, which is found in Archaea, is responsible for the production of over a billion tons of methane per year. David used a combination of electrochemical, computational, and reactivity studies to evaluate the suitability of these models and identified a particular macrocycle for chemical reactivity studies, reproducing the oxidation state range predicted for the native enzyme and preparing an important methyl nickel derivative that is a close relative to the putative intermediated in MCR. David was joined in the lab by Jim Enterkin ’05, who worked on the synthesis of a new class of platinum complexes that, it is hoped, will serve as new anti-cancer drugs. Joining the lab this summer to continue this work are Ned Wydysh ’04 who will conduct his thesis research in Professor Schofield’s lab, and Erwin van der Geer, who is visiting Williams from the Netherlands as part of the Williams/Leiden University exchange program.

After returning from leave, Professor Schofield taught Introduction to Physical and Inorganic Chemistry (CHEM 256), the last introductory course in the “sandwich” model of the new chemistry curriculum. Although unlikely to appear as an option on the walls of Papa Charlie’s Deli, students were tantalized by a mixture of coordination chemistry, kinetics/mechanism and thermodynamics both in lecture and the new laboratory program (also salami, but we won’t go there...).

In addition to these on-campus activities, Professor Schofield continued his professional activities outside Williamstown. In August 2002, he attended the National ACS meeting in Boston and in March 2003, he presented his work at the National ACS meeting in New Orleans. This July he will attend the Gordon Research Conference on Cobalamin Chemistry in Waterville, ME, and after a five-day hiatus in Williamstown, the 11th International Conference on Biological Inorganic Chemistry in Cairns, Australia. Professor Schofield also served as a reviewer for Inorganic Chemistry, Journal of the American Chemical Society Proceedings of the National Academy of Sciences, and the National Science Foundation.

This spring saw the introduction of Introduction to Physical and Inorganic Chemistry (CHEM 256) to the curriculum. This completes the new four-semester introductory series. Dr. Skinner taught the majority of labs for this course, following teaching in Concepts of Chemistry (CHEM 151) in the fall.

Dr. Skinner’s research uses electron spin resonance (ESR) to date fossils. In the summer of 2002, she had three Williams students, Sara Martin ’05, Dean Laochamroonvorapongse ’03 and Terry-Ann K. Suer ’05 in her lab. Students also participated in her research during January as part of Winter Study.

In April 2003, Dr. Skinner attended two professional meetings being held serially in Tempe, AZ. The first, the Paleontology Society, she presented the results from her study of the Late Stone Age at Olduvai Gorge, Tanzania. Her date of 55,000 years ago makes this one of the earliest such sites. Later in the week, she presented a study on a Neanderthal site in the Caucasus on which Sara Martin is a co-author.

Next spring Dr. Skinner will offer a tutorial course on scientific method in archaeology and paleontology. This will increase the number of lower-level Division III tutorials. Dr. Skinner continues as News and Features Editor of the Council on Undergraduate Research Quarterly.

After welcoming twin daughters Keiko and Amaya into the world in July 2002, Tom Smith spent this fifth year as an Assistant Professor pursuing his research in organic synthesis and methods development along with senior honors student, Jennifer Roizen ’03. In April, Jenny and future thesis student Vicky Bock ’04 traveled to New Orleans, LA, to present a poster at the National Meeting of the American Chemical Society.

Jenny continued a project begun by former honors student Emily Balskus ’02 on the asymmetric total synthesis of hennoxazole A, an antiviral natural product isolated from a marine sponge. Hennoxazole A has been shown to be highly active against the herpes simplex virus (HSV-1, IC50 = 0.6 /ML). Jenny advanced the forefront of this approach toward the total synthesis of this interesting natural product by five steps.

Another project underway in the Smith lab is directed at a general asymmetric synthesis of the kavalactones. These natural products, including kavain, are the active constituents of the kava plant, which has been used for centuries in South Pacific cultures for its sedative and muscle relaxing effects. Modern interest in the compounds from this herbal tonic stems from their reported ability to relieve anxiety. Previous work by thesis students Mabel Djang ’01 and Alan Velander ’02 has led to the first asymmetric synthesis of (+)-kavain and a three-step synthesis of (+)-dihydrokavain. Summer student Kathleen Carroll ’05 will put the finishing touches on this project in preparation for publication.

Honors student Adrian Dowst ’04 will continue a project toward the asymmetric total synthesis of jerangolid D, an antifungal natural product isolated from myxobacteria, in which the methods developed for kavalactone synthesis are extended to the assembly of both the -lactone and cis-dihydropyran portions of this molecule. Professor Smith also received a grant from the National Science Foundation, Asymmetric Synthesis of Pyran-Based Natural Products, for $177,308 to continue this work.

In the classroom this year, Professor Smith took on two new teaching posts. In the fall semester, he taught Fighting Disease: The Evolution and Operation of Human Medicine (CHEM 111). This course provided an introduction to concepts in medicinal chemistry, biochemistry, and pharmacology to 30 eager non-chemistry majors. A final poster presentation by the class covered topics ranging from the origins and treatment of African river blindness to an analysis of methods of birth control administration to the use and abuse of creatine and anabolic steroids by athletes. In the spring semester, Professor Smith taught Organic Chemistry: Introductory Level (CHEM 156) to 110 potential chemistry majors and premedical students. A full recovery is expected. Professor Smith looks forward to another productive and invigorating year of teaching and research.

Working with Adam Steeves ’02, Professor Jay Thoman continued research on the behavior of chlorofluorocarbon substitute molecules with chemically significant amounts of energy. Working during summer 2001 and on a senior thesis project, Adam measured the vibrational overtone spectroscopy of a series of hydrofluorocarbons, concentrating on the fire-suppressant molecule 1,1,1,2,3,3,3-heptafluoropropane. While most of the measurements were made using long-path (up to 20m) absorption, Adam also implemented a laser-based technique known as cavity ringdown spectroscopy, which provides an equivalent path length of kilometers. Cavity ringdown spectroscopy now works much more straightforwardly in Thoman’s lab, thanks to the acquisition of a new Nd:YAG-pumped dye laser system in May 2002.

Working with Jason Leith ’05, Brain Saar ’05, and Saroj Bhattarai ’05, Professor Jay Thoman continued research on the behavior of small molecules with chemically significant amounts of energy. In summer 2002, the team investigated the vibrational overtone spectroscopy of gaseous and liquid methanol and ethanol using the sensitive laser-based technique of cavity ringdown spectroscopy. They demonstrated the advantages and limitations of using a quartz cell held at Brewster’s angle in comparison to a cell in which the sample is held in contact with the (expensive!) ringdown mirrors. During the academic year, Leith continued as a thesis student and Saar as a work-study student. They probed the vibrational overtones of hydrofluorocarbons, making extensive measurements on the hydrofluoroethanes, and identifying the extent to which Fermi resonance explains the frequencies and intensities of the observed transitions.

In the fall semester, Thoman taught Physical Chemistry: Thermodynamics (CHEM 301) for the first and last time. With the introduction of the new chemistry curriculum, the physical chemistry sequence is reversed from a phenomenological approach (thermodynamics first) to a molecular approach (quantum mechanics first). With help from Professor Peacock-López, Thoman introduced a new computational laboratory in which students learn the fundamentals of the software package Mathematica. He also introduced a new laboratory exercise using the differential scanning calorimeter to investigate phase transitions in ammonium nitrate and several polymers. During Winter Study, Thoman sponsored Brain Saar ’05 in Introduction to Environmental Science Research (CHEM 026), and again taught Glass and Glassblowing (CHEM 016). In the spring, Thoman co-taught two classes Instrumental Methods of Analysis (CHEM 304) with Professor Lee Park and Introduction to Environmental Science (ENVI 102) with Geosciences Professor Heather Stoll.