Researchers have documented the ultrafast motion of electrons that drive the making and breaking of chemical bonds, including two processes never before captured on their natural timescales.
Key takeaways:
- Researchers used SLAC’s X-ray laser to image early electron movement at attosecond timescales in what’s known as an “impulsively ionized” molecule.
- They captured two processes never before seen in real time: Coster-Kronig decay and quantum electron coherence.
- Experimental results contradicted leading computer simulations, forcing theorists to incorporate additional complexity for more accurate predictive models.
All chemistry starts with a push from electrons. In the early moments of a chemical reaction, it’s the movement of electrons that initiates the breaking of old chemical bonds and forging of new ones, transforming one molecule into another.
When an electron is removed from a molecule faster than the molecule can react – called “impulsive ionization” – the other electrons in the molecule enter excited quantum states that evolve on ultrafast timescales. Scientists have long sought to map the ultrasmall, ultrafast electronic motions behind chemical reactions on their natural timescales.
Now, researchers at the Department of Energy’s SLAC National Accelerator Laboratory have created a movie of early electron motion in an impulsively excited molecule. Each frame captures changes happening in mere attoseconds, just billionths of a billionth of a second. Their results, published in Nature Physics, map the early steps of a photochemical reaction, similar to the reactions that drive countless processes – from X-ray interactions in medical settings to cosmic ray collisions in the upper atmosphere. Their results reveal steps of these processes never before resolved in time.
Read more on the SLAC website