Crystals make an elusive boron–oxygen bond accessible
· BehindLines newsroom
Chemists have obtained three oxoboranes stable enough to isolate as crystals at room temperature. These molecules contain a triple bond between boron and oxygen, which is difficult to preserve in free compounds. The study, published on 27 October in Nature Chemistry, was presented by the University of Würzburg on 28 October. This is a recent result, rather than a discovery announced on 8 November.
From a trace to a sample
The experiment's value lies in what researchers can now examine. Chemists have sought oxoboranes since the 1960s. Earlier experiments detected them under particular conditions or produced forms stabilised by other chemical partners. Isolating these new compounds allows their structure and reactions to be studied directly.
Lukas Lubczyk and Christian Markl, working in Holger Braunschweig's team, reacted a diboracumulene with reagents bearing a carbonyl group. The resulting coloured solids offered an unexpected lead. The Würzburg team worked with Ashwini K. Phukan's team at Tezpur University on the calculations.
Short, strong bonds
The paper describes particularly short bonds and links their stability to the molecule's electronic environment. According to the abstract published by Nature Chemistry, the boron–oxygen bond lengths range from 1.208 to 1.217 ångströms, which the authors describe as short bonds.
For fundamental research, the change is tangible. Having a compound that can be isolated opens up experiments that were previously difficult. It does not, however, provide a commercial material ready for use or a demonstrated industrial application. The next question is which transformations this family of molecules makes possible, and how far the method can be extended.