Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Jason A. Widegren (Fed)

Research Chemist, NMR Facility Manager

Dr. Widegren attended The Colorado College and graduated with a B.A. in chemistry. During the summers he did undergraduate research on photocatalytic oxidations with Professor John L. Falconer in the Chemical Engineering Department at the University of Colorado. His graduate studies were done in the Chemistry Department at Colorado State University with Professor Richard G. Finke. His Ph.D. thesis focused on the synthesis and catalytic properties of metal nanoparticles. After graduate school, he spent a year as a visiting professor at Adams State University, where he taught classes in general and analytical chemistry. He began his career at NIST with NRC and PREP Postdoctoral Fellowships, during which he studied the thermophysical properties of ionic liquids with postdoctoral advisor, Dr. Joseph W. Magee. He is currently the NMR Facility Manager for NIST Boulder and the Group Safety Representative for the Fluid Characterization Group. Dr. Widegren is also part of a new team and research program at NIST that received the Innovations in Measurement Science Award, funding to develop spectroscopic measurements of intermolecular interactions in solution. Away from work, he enjoys gardening, beekeeping and traveling.

Google Scholar Citation Page

Research Areas:

NMR spectroscopy at controlled temperatures and pressures

Dr. Widegren’s current research with NMR spectroscopy is focused on measurements in which temperature, pressure, and mixture composition must be determined simultaneously. Applications include measurements of vapor-liquid equilibrium of refrigerant mixtures, competitive gas adsorption on activated carbon, and the pressure dependence of chemical separations. This work has included improvements to measurements of mixture composition for gas-phase and multiphasic samples. It also strives to improve the fundamental metrology associated with temperature and pressure measurements in the presence of high magnetic fields. A noteworthy new project is to use NMR spectroscopy to validate the performance of electric-acoustic spectroscopy, which is a method being developed at NIST to measure intermolecular interactions in solution:…

Vapor pressure measurements of low-volatility, unstable compounds

Another active area of research is the measurement of vapor pressures for low-volatility compounds. This work is largely focused on the optimization of apparatus design and measurement methodology so that low-uncertainty measurements on unstable compounds are possible. Recently, we invented dynamic vapor microextraction (DVME) for these high-accuracy measurements and ultimate deployment to in-the-field vapor detection.  Applications include measurements on taggants for explosives (where vapor pressures are important for detection), biodiesel esters (where vapor pressures are needed for bio-refinery design), organic aerosol formers (where vapor pressures are needed for climate modeling), and cannabinoids (where vapor pressures are needed for breathalyzer development).

Other thermophysical property measurements

Dr. Widegren also studies the thermal stability of organic compounds, enthalpies of adsorption, and permeation through polymers.


●Innovations in Measurement Science Award, NIST (2020)

● Material Measurement Laboratory Outreach Award (2018)

● NIST Safety Award (2010)

● PREP Postdoctoral Fellowship, University of Colorado/NIST (2005)

● National Academy of Sciences/National Research Council (NAS/NRC) Postdoctoral Fellowship (2003)

● Union Carbide Corporation's Student Innovation Recognition Award (2001)

● Merck Award for the outstanding chemistry graduate, Colorado College (1994)


Created September 19, 2019, Updated December 8, 2022