A group of researchers at the University of Tokyo have spent years testing the limits of chemical bonds. And now, after years of work, they’ve finally explored an idea originally proposed in 1931: a chemical bond formed using just a single electron. This, of course, poses quite a conundrum, as many believe single-electron chemical bonds can’t exist.
That’s because all of the current known covalent bonds—where atoms connect by sharing their electrons—must contain two, four, six, or eight electrons. However, in 1931, Linus Pauling theorized that a covalent bond could exist with atoms sharing a single electron.
However, creating a new single-electron chemical bond isn’t easy. To find out if it is possible, researchers started with a covalent bond that already exists with two electrons. They then removed one of those electrons by using a chemical reaction. They used a large hydrocarbon with long bonds between its carbon atoms to help ensure the energy cost would be too great for an electron from elsewhere to replace the one they removed.
While past experiments to try to remove electrons from covalent bonds haven’t quite panned out, the group was able to stabilize their bond enough to actually take an analysis of it using X-rays of the atom and even several different kinds of light.
Based on how it bounced off the bond, the researchers believe they were able to achieve an actual stable single-electron bond. Of course, the real benefit here is studying how these one-electron bonds might change chemical reactions altogether. But the researchers also have other questions.
For starters, the researchers involved hope to further clarify exactly what a covalent bond is and then determine what exactly causes a bond to qualify as covalent, at which point it doesn’t qualify as such. The researchers have published their findings in the journal Nature.
