Chemistry Department
Timothy Barnum profile photo

Timothy Barnum

Job Title
Assistant Professor of Chemistry
ISEC 257

Areas of expertise

Physical chemistry, Molecular spectroscopy, Computational chemistry, Rydberg states

Research interests

Our team uses quantum chemical calculations and high resolution rotational spectroscopy to probe the structure and dynamics of interesting small molecules, especially reactive intermediates involved in combustion and other high energy chemical systems. Student researchers in our group can develop skills in a wide range of areas dependent on interest, including vacuum instrument design and fabrication, computerized data collection, computational chemistry, microwave electronics and signal analysis, and assignment and fitting of spectroscopic data. We also interface with the GOTHAM collaboration, which seeks to identify and understand the presence of complex organic molecules in the interstellar medium.

Teaching interests

CHM 101 Introductory Chemistry I & Lab
CHM 351 Kinetics and Thermodynamics & Lab
CHM 352 Quantum Chemistry & Lab

Additional media

Publications & Recent Funding

  • Publications
    • Mishra P, Hull AW, Barnum TJ, McGuire BA, Field RW. Chirped-pulse Fourier-transform millimeter wave rotational spectroscopy of furan in its ν10 and ν13 excited vibrational states. J. Mol. Spec. 2022, 388, 111686.
    • Barnum TJ, Siebert MA, Lee KLK, Loomis RA, Changala PB, Charnley SB, Sita ML, Xue C, Remijan AJ, Burkhardt AM, McGuire BA, Cooke IR. A search for heterocycles in GOTHAM observations of TMC-1. J. Phys. Chem. A. 2022, 126, 2716-2728.
    • Barnum TJ, Clausen G, Jiang J, Coy SL, Field RW. Long-range model of vibrational autoionization in core-nonpenetrating Rydberg states of NO. J. Chem. Phys. 2021, 155, 244303.
    • Barnum TJ, Lee KLK, McGuire BA. Chirped-pulse Fourier transform millimeter-wave spectroscopy of furan, isotopologues, and vibrational excited states. ACS Earth Space Chem. 2021, 5(11), 2986-2994.
    • Barnum TJ, Herburger H, Grimes DD, Jiang J, Field RW. Preparation of high orbital angular momentum Rydberg states by optical-millimeter-wave STIRAP. J. Chem. Phys. 2020, 153(8), 084301.
    • Bergmann K, Nägerl HC, Panda C, Gabrielse G, Miloglyadov E, Quack M, Seyfang G, Wichmann G, Ospelkaus S, Kuhn A, Longhi S, Szameit A, Pirro P, Hillebrands B, Zhu X-F, Zhu J, Drewsen M, Hensinger WK, Weidt S, Halfmann T, Wang H-L, Paraoanu GS, Vitanov NV, Mompart J, Busch T, Barnum TJ, Grimes DD, Field RW, Raizen MG, Narevicius E, Auzinsh M, Budker D, Pálffy A, Keitel CH. Roadmap on STIRAP applications. J. Phys. B. 2019, 52(20), 202001.
    • Jiang J, Barnum TJ, Coy SL, Field RW. Analysis of vibrational autoionization of CaF Rydberg States. J. Chem. Phys. 2019, 150(15), 154305.
    • Transue WJ, Yang J, Nava M, Sergeyev IV, Barnum TJ, McCarthy MC, Cummins CC. Synthetic and spectroscopic investigations enabled by modular synthesis of molecular phosphaalkyne precursors. JACS. 2018, 140(51), 17985-17991.
    • Grimes DD, Barnum TJ, Zhou Y, Colombo AP, Field RW. Coherent laser-millimeter-wave interactions en route to coherent population transfer. J. Chem. Phys. 2017, 147(14), 144201.
    • Grimes DD, Coy SL, Barnum TJ, Zhou Y, Yelin SF, Field RW. Direct single-shot observation of millimeter-wave superradiance in Rydberg-Rydberg transitions. Phys. Rev. A. 2017, 95(4), 043818.
    • Zhou Y, Grimes DD, Barnum TJ, Patterson D, Coy SL, Klein E, Muenter JS, Field RW. Direct detection of Rydberg-Rydberg millimeter-wave transitions in a buffer gas cooled molecular beam. Chem. Phys. Lett. 2015, 640, 124-136.
    • Fusco D, Barnum TJ, Bruno AE, Luft JR, Snell EH, Mukherjee S, Charbonneau P. Statistical analysis of crystallization database links protein physico-chemical features with crystallization mechanisms. PLoS ONE. 2014, 9(7), e101123.
    • Barnum TJ, Medeiros N, Hinrichs RZ. Condensed-phase versus gas-phase ozonolysis of catechol: A combined experimental and theoretical study. Atmos. Environ. 2012, 55, 98-106.

  • Recent Funding
    • American Chemical Society Petroleum Research Fund Undergraduate New Investigator, 66472-UNI6, Identification and structure determination of reactive intermediates in the reactions of NOx and resonance-stabilized hydrocarbon radicals, $55,000, 9/1/2023 - 8/31/2025.

Academic credentials

B.A., Drew University; Ph.D., MIT; Postdoc, MIT