Photo of McMahon | Woods Group Members

Group Members

Faculty and Staff

Robert McMahon

Credentials: Ph.D. University of California, Los Angeles 1985

Position title: Professor

Email: robert.mcmahon@wisc.edu

Address:
Department of Chemistry, Room 6209A
University of Wisconsin-Madison
1101 University Avenue
Madison, WI 53706

ORCID-iD iconhttps://orcid.org/0000-0003-1377-5107

Robert J. McMahon was born in Mendota, Illinois in 1958. He received a B.S. degree in Chemistry from the University of Illinois at Urbana-Champaign in 1980. He performed undergraduate research with Professor Stanley G. Smith into the mechanism and stereoselectivity of lithium aluminum hydride reduction of ketones. McMahon received a Ph.D. degree in Organic Chemistry from the University of California, Los Angeles in 1985, working with Professor Orville L. Chapman on the mechanisms of carbene rearrangements. From 1985-1988, McMahon investigated excited-state electron transfer as a postdoctoral research associate with Professor Mark S. Wrighton at the Massachusetts Institute of Technology. McMahon accepted a position on the faculty in the Department of Chemistry at the University of Wisconsin-Madison in 1988 and was promoted to full professor in 1997. He was named an Associate Editor of the Journal of Organic Chemistry in 2000 and a Fellow of the American Association for the Advancement of Science in 2003.

R. Claude Woods

Credentials: Ph.D. Harvard University 1965

Position title: Professor

Email: rcwoods@wisc.edu

Phone: 608-262-2892

https://www2.chem.wisc.edu/users/woods

Claude Woods was born March 24, 1940 in Atlanta, Georgia. He graduated with a BS in Chemistry from Georgia Institute of Technology in 1961. He obtained an AM degree (1962) and then a PhD degree (1965) in Physical Chemistry from Harvard University. He served for two years on active duty as a Lieutenant in the US Naval Reserve (1965-1967), during which time he was an officer instructor in Chemistry at the US Naval Academy in Annapolis, Maryland. He was a faculty member at the University of Wisconsin-Madison in the Department of Chemistry for fifty three years: Assistant Professor (1967-1973), Associate Professor (1973-1977), and Professor (1977-2020), retiring in August, 2020. His major research areas are high resolution spectroscopy, quantum chemistry, astrochemistry, and plasma processing and diagnostics. In 1984 he shared the Nobel Laureate Signature Award for Graduate Education in Chemistry, awarded by the ACS for the outstanding PhD thesis in Chemistry in the United States, with his graduate student Christopher Gudeman. In 1997 he received the Pharmacia-Upjohn Excellence in Teaching Award from the Department of Chemistry, and in 2013 he received the Undergraduate Mentoring Award in Physical Sciences from the University of Wisconsin-Madison.

Brian Esselman

Credentials: Ph.D. University of Wisconsin–Madison 2012

Position title: Organic Chemistry Lecturer and Assistant Laboratory Director

Email: brian.esselman@wisc.edu

ORCID-iD iconhttps://orcid.org/0000-0002-9385-8078

https://www2.chem.wisc.edu/users/besselman

Brian first came to the University of Wisconsin–Madison in the fall of 1995 as a college freshman and received his B.S. in Chemistry and Chemistry-Secondary Education in December of 2000.  In May 2004, he received an M.S. in Educational Psychology from the University of Wisconsin.  He completed his UW–Madison education with a Chemistry Ph.D. in 2012 on the Computational and Spectroscopic Investigation of Species of Astrochemical Relevance.  During his last two years of graduate school he played an important role in the updating and upgrading of the mm-wave spectrometer used by the group and led the analysis of the pyridazine rotational spectrum.

While in graduate school, Brian collaborated with Nick Hill in the undergraduate organic laboratory to implement computational chemistry as an integral part of the undergraduate curriculum.  This naturally led to Brian’s current position as an organic chemistry instructor and laboratory director at UW–Madison.  His research interests have expanded to include chemical education and curriculum development.  In 2017, he was awarded the Harvey Spangler Award for Technology Enhanced Instruction by the College of Engineering, The Early Career Award by the College of Letters & Science, and the Taylor Teaching Award by the Department of Chemistry.  Since graduating, he has continued to collaborate with Bob and Claude, mentor graduate and undergraduate students in research, and investigate the spectroscopy of several molecules.  He was given the GSFLC mentor award in 2019 for his work with graduate students in the group and teaching assistants in the organic laboratory.

Graduate Students

Matisha Dorman

Credentials: Ph.D. Candidate

Position title: 5th Year Graduate Student

Email: dorman3@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6207

ORCID-iD iconhttps://orcid.org/0000-0003-3802-6719

Matisha received a B.S. in Chemistry from the University of West Florida in 2016. During her undergraduate career, she worked in Dr. Karen Molek’s research lab. There, she studied the chemical kinetics of asphaltene adsorption onto nanoparticles using a home build MALDI mass spectrometer. She spent the summer of 2015 in Madison with the McMahon group and came back for graduate school to call the group home. Currently, she is working to optimize and prepare the group’s rotational spectrometer for ion spectroscopy work which will pave the way for more projects in the future. When not enjoying the sciences, Matisha spends time with her husband and two dogs, exploring Madison and keeping them out of trouble.

Recent Publication:

Dorman, P. M.; Esselman, B. J.; Park, J. E.; Woods, R. C.; McMahon, R. J. Millimeter-Wave Spectrum of 4-Cyanopyridine in its Ground State and Lowest-Energy Vibrationally Excited Dyad, ν20 and ν30J. Mol. Spectrosc. 2020, 369, 111274.  View Article

Madison Fellows

Credentials: Ph.D. Student

Position title: 4th Year Graduate Student

Email: mdfellows@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6212

Madison received a B.A. in Chemistry and Spanish from Grinnell College in 2017. During her undergraduate career, she interned at the CRF at Sandia National Laboratory, where she studied radical reaction pathways, in addition to NREL, where she investigated the effect of biofuel pyrolysis on catalysts. At Grinnell, she studied aerosol formation and catalyst chemistry with Herbierto Hernandez. Since joining the McMahon group, Madison has been studying astrochemically relevant compounds through computation and rotational spectroscopy. Outside of chemistry, Madison enjoys doing yoga, cooking, and watching cute animal videos.

Samuel Kougias

Credentials: Ph.D. Candidate

Position title: 7th Year Graduate Student

Email: kougias@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6207

ORCID-iD iconhttps://orcid.org/0000-0002-9877-0817

Sam received a B.S. in Chemistry from the University of Wisconsin – Oshkosh in 2014. While at UW Oshkosh, Sam worked under Dr. Kevin Crawford on a project involving HPLC method development for the separation of carotenoid pigments extracted from cell stains native to the Fox River. Additionaly, Sam worked under Dr. William F. Wacholtz to synthesize symmetrical bridging thiolate ligands used in closed-shell luminescent zinc (II) dimers. Since joining the McMahon group in 2016, Sam has worked on the synthesis and characterization of astrochemically relevant nitriles that are structural isomers of pyridine. Chemistry aside, Sam enjoys woodworking, fishing, camping, and committing antics.

Recent Publication:

Kougias, S. M.; Knezz, S. N.; Owen, A. N.; Sanchez, R. A.; Hyland, G. E.; Lee, D. J.; Patel, A. R.; Esselman, B. J.; Woods, R. C.; McMahon, R. J. Synthesis and Characterization of Cyanobutadiene Isomers – Molecules of Astrochemical Significance. J. Org. Chem. 2020, 85 (9), 5787-5798.  View Article

 

Vanessa Orr

Credentials: Ph.D. Candidate

Position title: 7th Year Graduate Student

Email: vorr@chem.wisc.edu

Phone: 608-262-0599

Address:
Chemistry Building, 6207

ORCID-iD iconhttps://orcid.org/0000-0003-0247-7075

Vanessa received a B.S. in Chemistry and a minor in Mathematics from California Lutheran University in 2014. While there she worked on the optimization of direct arylation, a type of palladium-catalyzed cross coupling, under the advisement of Dr. John F. Tannaci. Since joining the McMahon | Woods group, she has been working in the rotational spectroscopy sub-group. In collaboration with Kaori Kobayashi’s Group and John F. Stanton, she is working on the semi-equilibrium structure determination of thiophene. This project involves analysis of 20+ isotopologues and applying computational methods presented in the pyrimidine project to a sulfur-containing heterocycle. The vibrational states of thiophene below ~1100 cm-1 have been analyzed as a separate project. Another on-going project centers on the analysis of the vibrational states of the anti-clinal conformer of 4-cyano-1,2-butadiene, which was synthesized by Sam K. with the help of undergraduate researchers and was recently published in JOC. This molecule involves the internal rotation of an asymmetric top with an asymmetric frame, and interesting coupling of the harmonics of the vibrational states that correspond to this rotation. When not working on chemistry, Vanessa enjoys singing, listening to music, walking by the Madison lakes, and traveling.

Recent Publication:

Orr, V. L.; Esselman, B. J.; Dorman, P. M.; Amberger, B. K.; Guzei, I. A.; Woods, R. C.; McMahon, R. J. Millimeter-wave Spectroscopy, X-ray Crystal Structure, and Quantum Chemical Studies of Diketene – Resolving Ambiguities Concerning the Structure of the Ketene Dimer. J. Phys. Chem. A. 2016, 120 (39), 7753-7763.  View Article

Andrew Owen

Credentials: Ph.D. Candidate

Position title: 6th Year Graduate Student

Email: aowen4@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6207

ORCID-iD iconhttps://orcid.org/0000-0001-5903-1651

Andrew received a B.S. in Chemistry from the University of North Dakota in 2015. During his time there, he worked under Professor Irina Smoliakova on an organic synthesis project related to renewable fuels as part of an REU program. After that, he worked under Professor Jerome Delhommelle on a project to characterize hydrogen sulfide phase properties using molecular dynamics simulations. Finally, he worked under Professor Mark Hofmann to carry out structure determinations of various antimony oxides using ab initio calculations.

In the McMahon group, Andrew applies computational methods and his understanding of quantum mechanics to support current and future research projects. This includes explaining the observed diastereoselectivity in the synthesis of cyanobutadienes, predicting the stability of the carbon condensation products of highly unsaturated carbon chains, and implementing a priori predictions of vibration-rotation coupling for rotational spectroscopy. Recently his focus has been on applying improved theoretical methods to the structure determinations of hydrazoic acid and pyridazine, and analyzing the dependence of the structures on the isotopologues used to obtain them.

Andrew spends a lot of his free time reading books, playing board games with his girlfriend, and trying to find the missing puzzle pieces that her cat stole.

Recent Publication:

Kougias, S. M.; Knezz, S. N.; Owen, A. N.; Sanchez, R. A.; Hyland, G. E.; Lee, D. J.; Patel, A. R.; Esselman, B. J.; Woods, R. C.; McMahon, R. J. Synthesis and Characterization of Cyanobutadiene Isomers – Molecules of Astrochemical Significance. J. Org. Chem. 2020, 85 (9), 5787-5798.  View Article

Houston Smith

Credentials: Ph.D. Student

Position title: 3rd Year Graduate Student

Email: hhsmith2@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6212

ORCID-iD iconhttps://orcid.org/0000-0002-3762-1842

Houston received a B.S. in Chemistry from Emory University in 2018. During his time there, he worked with Dr. Widicus Weaver to experimentally create and study interstellar ice analogues. Since joining the McMahon group, he has been working in the rotational spectroscopy sub-group. Currently, he is working on the semi-experimental equilibrium structure determination of methacrylonitrile. This structure determination involves the analysis of 20+ isotopologues accounting for internal rotation within each and applying computational corrections to determine highly precise semi-experimental structural parameters for the molecule. Another current project is a least-squares fit of a Coriolis-coupled dyad of the two lowest-energy vibrationally excited states of 2-cyanopyrimidine. This least-squares fit requires a two-state Hamiltonian to adequately model the experimental spectrum. When not doing research, Houston enjoys playing video games, spending time with family, and traveling.

Samuel Wood

Credentials: Ph.D. Candidate

Position title: 4th Year Graduate Student

Email: sawood5@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6207

ORCID-iD iconhttps://orcid.org/0000-0001-8204-2770

Samuel Wood received his B.S. from Iowa State University in 2016. While at ISU, Sam studied self-assembling organic radicals under the advisement of professor Arthur H. Winter. Since joining the group, Sam’s research has focused on heavy atom tunneling and synthesis of astrochemically relevant compounds. Outside of the lab, Sam enjoys yoga, camping, and cooking.

Recent Publication:

Nunes, C. M., Viegas, L. P., Wood, S. A., Roque, J. P. L., McMahon, R. J., Fausto, R. Heavy-Atom Tunneling Through Crossing Potential Energy Surfaces: Cyclization of a Triplet 2-Formylarylnitrene to a Singlet 2,1-Benzisoxazole. 2020, Ang. Chem. Int. Ed. manuscript accepted.  View Article

Maria Zdanovskaia

Credentials: Ph.D. Candidate

Position title: 5th Year Graduate Student

Email: zdanovskaia@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6212

ORCID-iD iconhttps://orcid.org/0000-0001-5167-8573

Maria Zdanovskaia received a B.S. in Psychology and Certificate in Mathematics from UW – Madison, but decided to pursue physical organic chemistry in graduate school.  She has been studying the rotational spectroscopy of small aromatic heterocycles and substituted aromatic compounds.   She has employed organic syntheses, rotational spectroscopy, and computational chemistry to determine the precise equilibrium (reSE) structures of 1H- and 2H-1,2,3,-triazoles, thiazole, and pyridine.  These precise equilibrium structures use the rotational constants of many isotopologues and coupled-cluster calculations to produce the most accurate molecular structures possible by current methods.

Additionally, Maria has measured, assigned  as well the rotational spectra of benzonitrile and its isomer phenyl isocyanide, two compounds of astrochemical interest.  She has obtained least-squares fits of their two lowest energy vibrationally excited states, which form a Coriolis-coupled dyad.  These dyad fits allow for a highly precise determination of the vibrationally energy difference due to the transitions involved in sharp resonances and nominally forbidden interstate transitions.  Using a sample of 2-cyano-1,3-butadiene prepared by Sam K., Maria has obtained the rotational spectrum of the ground state and the Coriolis-coupled dyad of its two lowest energy fundamentals for the first time.

Maria assisted in the measurement, assignment, and least-squares fitting 2-chloropyridine and 2-chloropyrazine.  Due to the many well-isolated vibrationally excited states accessible for these molecules, spectroscopic constants for over 20 vibrational states were obtained.  These works allowed for a comparison between the experimental and computational vibration-rotation interaction constants.

Maria is also engaged in developing materials for chemical education using computational molecular modeling, including a website generated for organic laboratories at collaborating community colleges that is free for use by all interested individuals.  She has also worked with a couple of high school teachers to help implement the use of computational chemistry at the high school level.  When not doing chemistry, Maria enjoys dancing, jigsaw puzzles, various crafts, writing Excel macros, and instigating innocent mischief.

Recent Publication:

Zdanovskaia, M. A.; Esselman, B. J.; Woods, R. C.; McMahon, R. J., The 130 – 370 GHz Rotational Spectrum of Phenyl Isocyanide (C6H5NC). J. Chem. Phys. 2019, 151, 024301.  View Article

Undergraduate Students

Taylor Adkins

Credentials: Undergraduate Researcher

Position title: 2nd Year Undergraduate Student

Email: tkadkins@wisc.edu

Phone: (608) 262-0599

Address:
Chemistry Building, Room 6212

Taylor is a second year undergraduate student studying chemical engineering and strongly considering a double major in chemistry. She is looking at the rotational spectra of mono- and di- deuterated thiazole’s vibrationally excited states. The hope is to discover how deuteration effects the spectroscopic constants of the vibrational states of thiazole. Outside of science, Taylor enjoys gardening, watching movies, and spending time in nature.