In a significant scientific advancement, researchers have successfully captured the first-ever imaging of an individual electron during a chemical process, utilizing ultrafast X-ray pulses. This groundbreaking achievement, published on August 20, 2025, in the journal Physical Review Letters, provides unprecedented insight into the fundamental mechanisms driving chemical reactions.
The team focused on observing the dynamic movement of a valence electron at the precise moment of ammonia molecule dissociation. This new approach overcomes previous limitations where X-ray scattering techniques primarily interacted with inner electrons, leaving the crucial valence electrons largely unobserved. Ian Gabalski, the lead author of the study, highlighted the profound implications of this work, suggesting that a deep understanding of valence electron behavior could optimize pharmaceutical development, foster more stable chemical technologies, and lead to the creation of advanced materials.
The experiment was conducted at the SLAC National Accelerator Laboratory, utilizing the Linac Coherent Light Source (LCLS). The ammonia molecule was chosen for its light atomic composition, which minimizes interference from inner electrons, thereby enhancing the clarity of the observed signal. The process involved exciting an electron in the ammonia molecule with ultraviolet radiation, initiating dissociation, and then using precisely timed X-ray beams to capture the electron cloud's movements.
Within the framework of quantum mechanics, electrons are understood as probability clouds. The researchers employed computer modeling to describe these clouds, and as X-ray waves passed through them, they scattered and interfered. This allowed for the reconstruction of images that tracked the electron's movements, with comparisons to theoretical models confirming the pivotal role of valence electrons in the observed changes.
Looking ahead, the research team plans to adapt this technology for more complex, three-dimensional environments, potentially leading to practical applications in fields such as regenerative medicine. This advancement marks a pivotal moment in the ability to observe and understand the fundamental processes shaping our world at the atomic level.