Scientists in Singapore have used Raman spectroscopy to identify unstable organometallic clusters in solution.

Many organometallic species, which are important in metal-catalysed organic synthesis, exist at very low concentrations and cannot be isolated from solution. This makes their characterisation difficult.

Marc Garland and colleagues at the National University of Singapore used Raman spectroscopy to reveal the spectrum of an organometallic compound in a dilute solution containing a number of other compounds. The researchers compared their results to the Raman spectrum that they had predicted using computer calculations. They found that the experimental and predicted spectra matched well. 'This allowed us to identify the dilute species present and obtain a good structural assignment without using x-ray diffraction,' said Garland.

The team's research focuses on the investigation of homogeneous catalytic reactions using spectroscopy, said Garland. Their aims are to identify the intermediate species in reactions, to help calculate the reaction kinetics. 'The big hurdle has been the deconvolution of the complex in situ spectra where a multiple of species are present simultaneously,' said Garland.   

The researchers plan to delve even deeper into the properties of these unstable species. 'The determination of all their time dependant concentrations and important physical parameters will allow us to have a better understanding of the complex catalytic events,' said Garland.
 
Jenna Wilson