UK scientists synthesise p-block metallacarboranes with two different architectures. 

Alan Welch and his team from Heriot-Watt University in Edinburgh have synthesised p-block metallacarboranes and reveal some unique experimental information on the relative trans influences on facial carbon and boron atoms in the cage. For the first time, Welch shows an experimental way of assessing the relative strengths of Sn-B and Sn-C bonds in supraicosahedral metallocarboranes. 

Evidence on the relative strengths of the Sn-B and Sn-C bonds can be gauged through the orientiation of the bipyridyl ligands to specific cage atoms. In this case the ligands are trans, with the ligands pointing towards the carbon atoms in the cage showing that Sn-C interactions are weaker than Sn-B. 

'We see great future potential in using the positioning of a wide variety of exopolyhedral ligands to signal unique experimental information on cluster bonding, in a range of cluster types,' explains Welch. 'In developing this new area we will combine our experimental work (synthesis and structure determination) with the results of DFT calculations,' he adds. 

Mary Badcock