Rhodium carbonyl duster

Rode et al. [64] investigated propylene hydroformylation by such a catalyst and measured the infrared spectra of the functioning catalyst. They conduded that the rhodium carbonyl duster was not the catalytically active spedes, but, instead, a mononuclear rhodium spedes was suggested to be the active spedes. 

Tri-/ -carbonyl-nonacarbonyltetrarhodium is the starting material for the synthesis of a large number of rhodium carbonyl duster compounds. ... 

Ichikawa et al. [207, 208] prepared mixtures of rhodium and iridium carbonyls in zeolite Y by reductive carbonylation of their salts. The carbonyls were suggested to be [Rh cIr6. (CO)i6] on the basis of infrared, EXAFS, and other results. The complexity of the mixture made it difficult to determine which clusters were present and in what proportions. The duster mixture was decarbonylated, giving clusters that were suggested to be Rhir clusters of various compositions. 

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