Researchers from Julius-Maximilians-Universität Würzburg, under the direction of Professor Holger Braunschweig, a boron specialist, have created a molecule with a boron-carbon triple bond, known as a “boryne,” which is an orange solid at room temperature. Along with characterizing the novel molecule, the scientists conducted preliminary reactivity tests. The findings are published in the journal Nature Synthesis.
Structure of the world's first molecule with a triple bond between boron (B) and carbon (C). Image Credit: Rian Dewhurst/Universität Würzburg
Their similar electrical characteristics, boron, carbon, nitrogen, and oxygen, can all form chemical triple bonds with one another. Examples include the nitrogen gas in the earth's atmosphere, which has two nitrogen atoms, and the gas carbon monoxide, which comprises one carbon and one oxygen atom.
Triple bonds between all four elemental combinations are recognized by chemistry but not between boron and carbon. This is surprising because boron and carbon have had stable double bonds for a long time. Furthermore, numerous molecules have triple bonds between two atoms of carbon or boron.
Boron Atom in an Uncomfortable Situation
The boron atom and carbon atoms are arranged linearly in the new molecule.
In combination with the triple bond, this is about as uncomfortable as it gets for boron, requiring very special conditions.
Rian Dewhurst, Study Co-Author, Julius-Maximilians-Universität Würzburg
This explains why creating a triple bond of this kind for the first time has taken so long.
What interests the Würzburg chemists about the new molecule is that “Compounds in which individual atoms feel ‘uncomfortable’ often show a very interesting reactivity,” explained Maximilian Michel, the Doctoral Student who made the molecule in the laboratory.
The team is now concentrating its future efforts on this exact reactivity. In the end, this could lead to new chemical synthesis tools. The results may also contribute to a better understanding of chemical structures and bonds.
Inspiration for Other Researchers
Another benefit that is often overlooked: Basic research like ours inspires other researchers to put their efforts and imagination into synthesizing compounds that might seem improbable. World-changing advances often emerge from these kinds of crazy ideas.
Rian Dewhurst, Study Co-Author, Julius-Maximilians-Universität Würzburg
For instance, the well-known product superglue happened by accident during attempts to make transparent plastics, while Teflon was found during research initially intended to develop new refrigerants.
Journal Reference:
Michel, M., et al. (2025) The synthesis of a neutral boryne. Nature Synthesis. doi.org/10.1038/s44160-025-00763-1.