Scientists capture the first images of atoms that bind and break
Scientists capture the first images of the union and breakdown of ATOMS in real time at a scale half a million times smaller than the width of a human hair
- Scientists from the United Kingdom and Germany filmed atoms that bind and break in the nanoscale
- The video shows two rhenium atoms that vibrate inside a ‘test tube’ of carbon nanotubes
- The video helps to understand the dynamics of individual molecules in real time.
Scientists have captured the first images of atoms joining on a scale approximately half a million times smaller than the width of a human hair.
Using advanced microscopy methods, the team of researchers from the United Kingdom and Germany captured the breakdown of a chemical bond between two rhenium atoms.
The video shows the two atoms to the left of the footage, between 0.1 and 0.3 nanometers, which appear as black spots as they join and break.
Atoms are “the building blocks of the world” and the matter around us is composed of layers and layers of atoms, unless they are a single layer material such as graphene.
Ultimately, everything is controlled by the way atoms interact: they represent explosions, chemical processes within the human body and how the sun generates energy.
Now, this rupture and formation of the two links has been recorded in an atomic scale film.
Scroll down to watch the video
The two rhenium atoms are on a scale the size of a human hair, between 0.1 and 0.3 nanometers.
“It was surprisingly clear how the two atoms move in pairs, which clearly indicates a link between them,” said Dr. Kecheng Cao, a research assistant at the University of Ulm in Germany, who performed the imaging experiments.
“It is important to note that as Re2 moves down the nanotube, the length of the link changes, indicating that the bond becomes stronger or weaker depending on the environment around the atoms.”
Filming chemical bonds that break or form in real time is a big challenge due to its nanoscopic size.
The team used a method called transmission electron microscopy (TEM), where a beam of high-energy electrons shines through a very thin sample.
In this case, the researchers used carbon nanotubes as a sample: atomically thin hollow carbon cylinders with molecular scale diameters (1-2 nm), as “miniature test tubes” for atoms.
“Nanotubes help us trap atoms or molecules, and position them exactly where we want,” said Professor Andrei Kholbystov, professor of nanomaterials at the University of Nottingham.
‘In this case we trap a pair of rhenium atoms (Re) joined to form Re2.
“Because rhenium has a high atomic number, it is easier to see in TEM than the lighter elements, which allows us to identify each metal atom as a dark spot.”
3D illustration of an atom, which is the smallest constituent unit of ordinary matter that has the properties of a chemical element
Once united, it is shown that the atoms of Re2 vibrate, distorting their circular shape to become ovals and stretching the bond between them.
The atoms finally broke down and the vibrations ceased, but a little later the atoms joined again, forming a Re2 molecule.
“What makes it challenging is that transition metals, like Re, can form bonds of different order, from simple to quintuple bonds,” said Dr. Stephen Skowron, Postdoctoral Research Assistant at the University of Nottingham.
‘In this TEM experiment we observe that the two rhenium atoms are linked primarily through a quadruple bond, providing new fundamental ideas in transition metal chemistry.
“The bonds between metal atoms are very important in chemistry, particularly to understand the magnetic, electronic or catalytic properties of materials.”
The team believes that electron microscopy can become a general method to study chemical reactions, similar to the spectroscopic methods widely used in chemistry laboratories, which use light rays.
The researchers, from the University of Nottingham and the University of Ulm, Germany, detailed their achievements in the journal Science Advances.
WHAT IS ELECTRONIC TRANSMISSION MICROSCOPY?
The transmission electron microscope is a very powerful tool for materials science.
A high energy electron beam shines through a very thin sample.
In this case, the sample is carbon nanotubes (CNT): cylindrical molecules of rolled sheets of single-layer carbon atoms (graphene).
The interactions between electrons and atoms can be used to observe characteristics such as structure.
It provides accurate images of the atomic positions and the activation of chemical reactions due to the energy transferred from the fast electrons of the electron beam to the atoms.
An image is formed from the interaction of electrons with the sample as the beam is transmitted through the sample.
The technique is used globally to observe the characteristics of micro and nanoparticles.