Cluster formation as the cause of deactivation of carbonyl-rhodium catalysts in hydroformylation of olefins*

Summary 1. Carbonyl-rhodium catalysts—under conditions of hydroformylation of olefins without one or several reagents, are deactivated as a result of irreversible formation of polynuclear clusters. 2. The composition and properties of clusters formed during deactivation and the rate and mechanism of cluster-formation depend on the medium, in which the process takes place. Hydrogen has the most marked effect. 3. Cluster formation takes place in stages. The first stages of this process yields clusters with relatively low MW, they can during hydroformylation take part in the removal of clusters, which results in partial reactivation of the catalyst.