IRIDIUM COMPOUNDS IN HOMOGENEOUS HYDROGENATION.

Abstract

Iridium is generally considered to be a less effective catalyst than the other platinum metals but when highly co-ordinatively unsaturated species of it are prepared they appear to be exceptionally active hydrogenation catalysts, even for reduction of sterically hindred olefins. A mechanism for this reaction has been postulated based on low temperature magnetic resonance evidence. As the reaction proceeds, catalytically inactive hydrogen bridged cluster compounds are formed but work is in progress to counter this deactivation by physically separating the catalytic centers on a polymer support.