Timothy S. Zwier

Biography

Tim Zwier joined Sandia National Laboratories’ Combustion Research Facility (CRF) in January 2020 after spending much of his independent research career in academia. Zwier had served as PhD research advisor for more than 40 graduate students and about a dozen post-doctoral research associates. His research interests span the areas of large-molecule spectroscopy and chemical dynamics. With other Gas Phase Chemical Physics program (GPCP) staff at Sandia, he is developing and using modern tools of gas-phase chemical physics to probe the spectroscopy and dynamics of molecules that can undergo conformational isomerization, structural isomerization, and/or chemical reaction on complex potential energy surfaces.

Current Research

We prepare and study molecules under state-resolved conditions to gain insight to their structures, relative energies, interconversion, and reaction at the highest levels of detail and quantitative accuracy. Double resonance measurements involving microwave, infrared, and ultraviolet spectra of individual isomers serve as a foundation for pump-probe experiments following selective electronic or infrared excitation of individual isomers.

Studies of the infrared and ultraviolet spectroscopy of large molecular ions and complexes are carried out in a versatile, multi-stage mass spectrometer shown in Figure 1 that incorporates a cryo-cooled ion trap. Single-conformation IR and UV spectra are recorded using IR-UV double resonance photofragment spectroscopy.

Our research group also uses a broadband chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer (Figure 2) outfitted for photoionization time-of-flight mass spectrometry (TOFMS). The TOFMS is used to optimize conditions for production of specific reactive intermediates before recording broadband microwave spectra over the 2-18 GHz range under those conditions. We are also developing a cryo-cooled buffer gas cell as an alternative means of studying reactive intermediates.

Research Interests

Gas phase molecular spectroscopy, chemical dynamics, conformational isomerization, multi-chromophore molecules, excited state spectroscopy and photochemistry, structural characterization of free radicals and reactive intermediates, studies of ions in molecular cavities, and atmospheric sulfur oxidation chemistry. Google Scholar

Professional Organizations & Leadership

• Purdue University
  • M.G. Mellon Distinguished Professor of Chemistry: 2007 to 2018
  • Department Head, Department of Chemistry: 2013 to 2017
  • Department Head, Department of Chemistry: 2004 to 2008
  • Professor of Chemistry: 1997 to 2006
  • Assistant, Associate Professor of Chemistry: 1988 to 1997
• Calvin College
  • Assistant Professor of Chemistry: 1983 to 1988
• The Journal of Physical Chemistry Letters
  • Senior Editor: 2010 to 2019
• The Journal of Physical Chemistry
  • Senior Editor: 2003 to 2009

Awards

Featured Publication

Molecular Cage Reports on Its Contents: Spectroscopic Signatures of Cryo-Cooled K⁺– and Ba²⁺-Benzocryptand Complexes

Casey D. Foley, Cole D. Allen, Kendrew Au, Chin Lee, Susan B. Rempe, Pengyu Ren, Edwin L. Sibert III, and Timothy S. Zwier

The Journal of Physical Chemistry A 2023, 127, 30, 6227-6240 (A: Structure, Spectroscopy, and Reactivity of Molecules and Clusters)

Publication Date (Web): July 21, 2023

DOI: 10.1021/acs.jpca.3c03457

Google Scholar Publications

2023

2022

2021

2020

Other Publications

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