Polymer-supported complexes. Part 4. Decarbonylation of polystyrene-anchored dicarbonyl rhodium(I) complexes and applications as catalysts in cyclohexene hydrogenation

Abstract

Comparative decarbonylation studies have been carried out on polymer-supported [Rh(CO)₂L](L = a polymer resin functionalised with pentane-2,4-dionate or ethyldithiocarbamate) and [RhCl(CO)₂L](L = a polymer resin functionalised with ethylamine or diphenylphosphine) complexes under various conditions. The complexes respond differently to thermal or photochemical treatments as well as in their reactions with NO and hydrogen. The amine and dithiocarbamato-derivatives undergo reversible decarbonylation and evidence for involvement of an intermediate for the amine derivatives is supplied by i.r. spectroscopy. The catalytic activities of these complexes are primarily determined by the ease with which loss of carbon monoxide takes place, and also whether the rhodium–polymer bond remains intact or not under hydrogenation conditions.