Scientists accidentally solve a chemistry mystery that lasted 60 years
After more than 60 years of unsuccessful attempts, scientists have finally isolated stable examples of elusive boron-oxygen molecules once considered too unstable to capture. The surprising breakthrough, achieved using relatively simple chemical reactions, could pave the way for an entirely new class of exotic compounds.
Key points
- Scientists at the University of Würzburg found a way to produce and isolate oxoboranes, molecules unstable for over 60 years.
- The oxoboranes formed unexpectedly from reactions between a diboracumulene and various ketones.
- The team prepared three different oxoboranes and is now testing how widely the method applies.
Researchers at the University of Würzburg in Germany have produced and isolated oxoboranes, unusual molecules that had been considered too unstable to study under ordinary laboratory conditions for more than 60 years. The work was led by Professor Holger Braunschweig, with computational support from Professor Ashwini K. Phukan's team at Tezpur University in India, and was published in Nature Chemistry.
Oxoboranes contain a triple bond between boron and oxygen. Chemists had pursued them since at least the early 1960s, detecting and trapping them only under extreme conditions or inferring their existence indirectly.
An accidental discovery
Two doctoral students, Lukas Lubczyk and Christian Markl, were separately studying reactions between a diboracumulene and various ketones. Both noticed distinctive orange or yellow solids forming, and oxoboranes turned out to be the main products even though other outcomes had seemed more likely.
Lubczyk said the result came as a surprise, noting that he never expected the diboracumulene to react that way, "let alone with multiple different, simple substrates."
Nearly everybody in the field had given up on oxoboranes, as they were thought to be just too unstable to be isolated.
— Holger Braunschweig
Three compounds prepared
Using the new method, the scientists prepared three different oxoboranes, suggesting the approach could reach a wider range of these molecules. The team is now examining how broadly the technique can be applied, including whether similar strategies could produce other elusive compounds.
Braunschweig said most researchers in the field had abandoned oxoboranes as too unstable to isolate, and the team was stunned to see them form spontaneously and persist long enough to be studied. Funding came from the German Research Foundation, the German Academic Exchange Service and India's Department of Science & Technology.
