For a little more than a century, chemists have believed that strong atomic links called covalent bonds are formed when atoms share one or more electron pairs. Now, researchers have made the first observations of single-electron covalent bonds between two carbon atoms.

Analysis using X-ray diffraction revealed an unprecedented closeness between the carbon atoms, hinting at the presence of single-electron covalent bonds. This groundbreaking discovery opens up new possibilities in the realm of chemical bonding and molecular structure.

Covalent bonds, in which two atoms are bound together by sharing a pair of electrons, form the scaffolding that underpins the majority of organic compounds. In 1931, the Nobel Laureate Linus Pauling suggested that covalent bonds made from just a single,

Chemists at Hokkaido University have experimentally confirmed the existence of a single-electron carbon-carbon bond for the first time (Nature 2024, DOI: 10.1038/s41586-024-07965-1 ). Linus Pauling proposed the concept of one-electron covalent bonds in 1931, but direct evidence of their existence in carbon systems had proved elusive.

At Hokkaido University in Japan, researchers led by Takuya Shimajiri and Associate Professor Yusuke Ishigaki have made the first-ever observation of a