Scientists have believed for decades that the body forms a very unstable molecule called a carbene from vitamin B1, or thiamine. The carbon atoms of these molecules have six electrons instead of the usual eight. This makes them extremely reactive and short-lived. In aqueous medium, carbenes have half-lives that can be as brief as picoseconds or nanoseconds.
Ronald Breslow, a chemist from 1958, proposed the idea.
This idea was almost unthinkable in 1958. Researchers struggled because carbenes are too unstable to be observed directly. This is especially true in an environment rich with water like the body.
This mystery is finally solved, 60 years after it was first posed.
Chemists have proved an old theory on vitamin B1 after decades of research. They may have also laid the foundation for a sustainable way to make drugs.
Vincent Lavallo and his team of University of California Riverside researchers have done what seems impossible. They synthesized stable carbenes in water. Then they isolated them from the solution.
Finally, the glass tubes were sealed, but the carbenes remained intact.
This is the first instance that anyone has ever been able observe a carbene stable in water,” said Lavallo. People thought it was crazy. Breslow had it right.
The findings of the study were published by Science Advances.
How did they do it?
A protective molecule was created, which Lavallo refers to as a “suit armor” that surrounds the carbene and prevents it from reacting or reacting with other substances. The team used this design strategy to allow the molecule, which is normally unstable to stay long enough for detailed study.
Scientists have demonstrated the stability of carbene using techniques like nuclear magnetic resonance (NMR) and X-ray Crystallography. This is strong proof that these molecules are present in water.
We were not trying to prove a theory, but rather exploring the chemistry of these molecules. Varun Raviprolu is the first author of this study. But it turned out that our research confirmed exactly what Breslow had proposed so many years before.
The discovery could change the way we produce key chemicals. Carbenes are catalysts in catalysis.
They enable chemical reactions that can be used to produce medicines, fuels and other materials. These processes are usually dependent on toxic substances. This new method could enable these reactions to occur in water.
Water is the best solvent because it’s plentiful, non-toxic and environmental friendly. Raviprolu said. If we can make these powerful catalysers work in water, it’s an important step towards greener chemistry.”
This discovery also helps scientists better understand the chemistry that occurs inside cells which contain a large amount of water. Researchers may be able to investigate other chemical transitory intermediates by stabilizing these ephemeral molecule.
There are many other intermediates that we have never isolated, like this.” Lavallo said. We may be able, with our protective strategy, to finally see and understand them.
Lavallo’s achievement is a significant milestone for a long career of studying the tricky molecules.
Just 30 years ago people believed that these molecules could not be created. He said.
Now we can put them in bottles with water. Breslow was correct in his statements.
The discovery has a wider message for Raviprolu:
If we invest more in science, something that is impossible today could be possible tomorrow.
Journal Reference
- Varun Tej Raviprolu, Aaron Gregory, Isaac Banda, Scott G. McArthur, Sarah E. McArthur, William A. Goddard, Charles B. Musgrave, Vincent Lavallo.
Breslow’s theory confirmed: A stable carbene in liquid water. Science Advances, 2025; 11 (15) DOI: 10.1126/sciadv.adr9681
