Haute-couture catalysts

Tailor-made ligands have allowed researchers to develop a unique catalytic system.

Piet van Leeuwen and his team, from the University of Amsterdam, The Netherlands, and the Universidade Federal do Rio Grande do Sul, Brazil, have prepared a rhodium catalyst with a ligand specially designed to allow the catalyst to perform well when used in an ionic liquid system. The big advantage of this system is that it is a two-phase, easy to separate system. This allows the products from the catalysis (in this case the hydroformylations of hexene and octene) to be removed and the catalyst to be recycled.

The ligand, a phenoxaphosphino-modified Xantphos-type ligand was designed and made so that, according to van Leeuwen, ’in this system the catalyst resides in the ionic liquid’. van Leeuwen has high hopes for the system, and says that ’the catalyst combines the best of all worlds in terms of selectivity, rate, separation technology and catalyst stability’.

Katharine Sanderson