Boroles get a stability boost

10-Aug-2015 - Germany

Boroles could be a highly interesting class of materials for practical use in photovoltaic or LED applications – if it weren't for the molecules' extreme instability. Chemists from Würzburg have now discovered a powerful stabiliser.

Boroles are boron containing molecules that have great electron-accepting ability. This makes them excellently suited for materials that could bring further improvements to photovoltaics or OLEDs. But so far, boroles have had one major drawback: They are highly unstable and decay virtually immediately when in contact with water or oxygen.

Chemists at the University of Würzburg have now made an important step forward: Todd Marder and fellow chemists at the Institute of Inorganic Chemistry have significantly stabilised borole molecules by adding a so-called fluoromesityl group, which makes the highly sensitive boroles about 600 times more resistant to water. As a result, the molecules are stable for ten to twelve hours compared to just one minute without the stabilising group. Their electron-accepting ability is fully preserved.

Now the new molecules' robustness will be verified in further tests. The fluoromesityl boroles have proved to be heat resistant and easily vapourable. Therefore, the Würzburg chemists are now eager to investigate whether the novel boroles can be vapour deposited on substrates in wafer-thin films. This would be a major prerequisite for technological applications. Moreover, the scientists are looking for other molecule groups that might stabilise boroles even more efficiently.

Original publication

Zuolun Zhang, Robert M. Edkins, Martin Haehnel, Marius Wehner, Antonius Eichhorn, Lisa Mailänder, Michael Meier, Johannes Brand, Franziska Brede, Klaus Müller-Buschbaum, Holger Braunschweig, and Todd B. Marder, "Taming the beast: fluoromesityl groups induce a dramatic stability enhancement in boroles", Chemical Science, 2015

https://www.chemeurope.com/en/news/154011/boroles-get-a-stability-boost.html