Rhodium, chlorotris structure

Chlorotris(triphenylphosphine)rhodium(I) forms [RhCl (02)(PPh3) ] (n = 2, 3) or [RhCl(02)(PPh3)2]2. The last complex is six coordinate and has structure (31). Ligand oxidation can also occur. A diagnostic test for the presence of O2 ligands is a band at 870-900 cm, attributable to vo-o, in the IR spectrum. 

Decarbonylation of (-I-)-(/ )- -methyl-2,2-diphenylcyclopropanecarbaldehyde (3, X = Me) also occurs upon treatment with chlorotris(triphenylphosphane)rhodium in refluxing benzoni-trile for 16 hours. Retention or partial racemization is observed depending on the structure of... 

Since the intermediacy of a-siloxyalkyl rhodium complex III (see Scheme 4) is strongly suggested in the hydrosilylation of terpene ketones catalyzed by chlorotris-(triphenylphosphine)rhodium(I) (7), such an intermediate most likely plays a key role in the asymmetric induction of the present system. The fundamental premise is to assume a square-pyramidal structure of the a-siloxyalkyl-rhodium intermediate VI, as shown in equation (18), on the basis of the established structures of dihydrido [46] and of silylhydrido [14, 32c, 47] complexes derived from the Wilkinson s rhodium(I) complex. 

---