Captured the 'One Trillionth of a Second' When Atoms Bond

[Asia Economy Reporter Junho Hwang] Domestic researchers have succeeded in real-time observation of the entire process in which atoms bond to form molecules. It is expected that by advancing this technology to observe the reaction processes of various catalysts or proteins at the atomic level, it will contribute to the development of highly efficient catalysts or new drugs. The research team led by Associate Director Hyochul Lee of the Nano Materials and Chemical Reactions Research Group at the Institute for Basic Science announced that their research results were published on the 25th (local time) in the international academic journal Nature.

Capturing the Moment of Bonding from Atoms to Molecules

The research team succeeded for the first time in the world in real-time observation of the temporal and spatial changes of atoms moving minutely at the scale of several angstroms (one hundred millionth of a centimeter) within a fleeting moment of several femtoseconds (one quadrillionth of a second).

The team observed the formation process of a gold trimer molecule using an improved experimental technique and structural change modeling analysis method that allowed them to see faster movements than before. To observe the femtosecond moment, they used a special light source, the X-ray free-electron laser (femtosecond X-ray pulse) of the Pohang 4th generation synchrotron radiation accelerator.

As a result, they clarified that the two chemical bonds connecting three gold atoms linearly do not form simultaneously; instead, one bond rapidly forms first within 35 femtoseconds, and the remaining bond forms sequentially after 360 femtoseconds.

The gold trimer is a compound composed of three gold atoms. In aqueous solution, the atoms are scattered nearby, and when exposed to light (laser), they react and begin chemical bonding.

Through this experiment, the team also observed that after chemical bonds are formed, the atoms do not remain fixed in place but undergo vibrational motion where the distances between atoms increase and decrease.

Potential Applications in Developing Highly Efficient Catalysts and New Drugs

The research team plans to elucidate the progress of various chemical reactions at the atomic level, including reactions occurring in large molecules such as proteins and catalytic molecules.

Senior researcher Jonggu Kim, the first author, said, "As a result of continuous research from a long-term perspective, we were able to complete the 'femtosecond X-ray diffraction method' that directly tracks the vibrations and reaction pathways of reacting molecules." He added, "In the future, by revealing the mechanisms of various organic and inorganic catalytic reactions and biochemical reactions occurring inside the body, we will be able to provide fundamental information for developing efficient catalysts and new drugs related to protein reactions."