Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory, or Berkeley Lab, have observed how methane distributes excess energy, providing insight into the evolution of molecular structures.
The research explores the interplay between light and matter in a methane molecule, according to Enrico Ridente, co-author of the study published in Science and a campus doctoral student. Ridente added that studying changes to the relaxation of methane after absorbing light explains why cations in methane are stable.
“We can now explain how the molecule distorts after losing an electron and how the energies of the electrons respond to these changes,” said Diptarka Hait, the other co-author of the study and a campus doctoral student, in a press release.
Ridente said his research team was able to time-resolve, or observe the changes to methane with respect to time, when conducting the study. He explained this was the first research that “characterized” these particular molecular distortions from their beginning to completion.
He added that studying a molecule’s vibrational changes can provide insight into how light can be used as a means to “finely tune” the dissociation of a molecule.
“This research proved that it is possible to time-resolve and observe ultrafast molecular distortions and that the effect of geometrical distortions has implications that were unknown before,” Ridente said in an email.
The study used an experimental technique known as soft X-ray transient absorption, which Ridente described as the “perfect tool” to make observations in real time. He added tabletop laser measurements and density-functional theory calculations were also used to conduct the study.
He noted this research focuses on “Jahn-Teller distortions,” or distortions that occur in both the solid and gas phases. Ridente said the team of researchers behind this study chose to examine a “fundamental” example of the impact that geometrical distortions can have on a small molecule.
“The strong collaboration and exchange of ideas between theory and experiment has been crucial to interpret the results,” Ridente said in the email.
Ridente initially gained interest in the subject after observing that geometrical distortions are found everywhere in nature. He also shared his desire to explore how the shape of a molecule impacts its chemical and physical properties.
When asked about future plans for the research, Ridente said he hopes to explore the cause of coherent dynamics that were observed after a fast geometric distortion in the study. He also noted wanting to apply the knowledge he gained from this research to other types of distortions.
“We would like to investigate more complex systems and try to observe transient species and geometries that cannot be observed with more traditional techniques,” Ridente said in the email.