For the first time observed carbon binding with only one electron: revolutionary discovery for textbooks
For the first time observed carbon binding with only one electron: revolutionary discovery for textbooks
Believe chemist Bindings, so -called covalent bonds, arise when atoms divide one or more electron pairs. Now researchers have made the first observations of simple electron covalent bonds between two carbon atoms.
This unusual binding behavior has already been observed between some other atoms, but scientists are particularly enthusiastic to see it in carbon. Carbon is the basic component of life on earth and an important part of industrial chemicals, including medicines, plastics, sugar and proteins. The discovery was published on September 25th in the magazine Nature 1 .
"The covalent binding is one of the most important concepts in chemistry, and the discovery of new types of chemical bonds has great potential to expand the comprehensive areas of chemical Science," says chemist Takuya Shimajiri from the University of Tokyo, which was part of the research team for carbon binding.
Most chemical bonds in molecules consist of a single pair of electrons that are shared between atoms. This is called covalent simple bonds. In particularly strong ties, atoms could share two electron pairs in a double bond or three pairs in a triple bond. However, chemists know that atoms interact in many other species and they hope to better understand what a chemical bond is by studying unusual binding types at the edge of the possible
Pauling’s suggestion
The concept of simple electron covalent bonds goes back to 1931 when the chemist Linus Pauling suggested it. At the time, however, chemists did not have the tools to observe such bonds, says Marc-Etienne Moret, chemist at the University of Utrecht in the Netherlands. These bonds are difficult to observe even with modern analysis techniques. "The situation in which only one electron forms a bond is very unstable," explains Moret. "This means that the binding can easily break and has a strong tendency to either emit or capture an electron to restore a straight number of electrons."
In 1998, scientists 2 A simple electron bond between two phosphorus atoms; Moret was part of a group that 3 2013 made a bond between copper and boron. Chemists have theorized that these unusual ties could possibly appear in short -lived intermediate structures that appear during chemical reactions. But in order to observe these moody bonds, chemists have to stabilize a connection that contains them. A stable connection that contains a simple electron C-C bond has so far escaped chemists.
Shimajiri says the key to observing the simple electron carbon binding was the careful design of a molecule that would stabilize it. The research team, to which the chemist Yusuke Ishigaki from Hokkaido University belonged, created a molecule that provides a stable “shell” from connected carbon rings that holds the carbon-carbon binding together in its center. This central binding is stretched to a relatively long length for a C-C bond, which makes it vulnerable to lose an electron in an oxidation reaction and to generate the elective simple electron bond.
stable binding
In order to grasp this connection in a stable, observable form, they crystallized. If the oxidation is carried out in the presence of iodine, the reaction provides a violet salt, whereby the stable shell of the molecule holds the simple electron C-C bond together inside. Then they used various analysis techniques to characterize the molecule and bond. Shimajiri notes that the connection is extremely stable under everyday conditions.
"In several chemical reactions, the participation of simple electron bonds has been proposed, but so far they have remained hypothetical," says Shimajiri. The creation of stable connections that contain these bonds could help researchers better understand what happens during these reactions.
Guy Bertrand, chemist at the University of California in Santa Barbara, was part of the team that made the simple electron bond in phosphorus. He says it is important to see this in carbon. "Every time you do something with carbon, this has a greater impact than with any other element," he explains.
Shimajiri hopes that the description of the simple electron carbon binding will help chemists to better understand the basic nature of chemical bonds. "We want to clarify what a covalent bond is - more precisely, at which point a bond is qualified as a covalent and at what point." Shimajiri, T. et al. Nature https://doi.org/10.1038/s41586-024-07965-1 (2024). canac, y. et al. Science 279, 2080–2082 (1998). Moret, M.-E. et al. J. Am. Chem. Soc. 135, 3792–3795 (2013).