Organorhodium(I) and -rhodium(III) complexes containing the ligand 1,1,1-tris((diphenylphosphino)methyl)ethane (triphos)

Article abstract of DOI:10.1021/om00110a011

Treatment of the complex [Rh(CO)₂(triphos)]PF₆ (triphos = MeC(CH₂PPh₂)₃) with the ligands L (L = PMe₃, PMe₂Ph, PEt₃, P(n-Bu)₃, P(OMe)₃, t-BuNC) resulted in the formation of complexes of the type [Rh(CO)L(triphos)]PF₆. The analogous complexes of PPh₃, ethylene, and propylene could not be prepared in this way but were synthesized by displacing molecular hydrogen from the complex [RhH₂(CO)(trip-hos)]PF₆, prepared by the photochemical oxidative addition of H₂ to [Rh(CO)₂(triphos)]PF₆. The σ-bonded organorhodium(I) complexes RhR(CO)(triphos) (R = Me, Ph) were prepared by treating RhCl(CO)(triphos) with the appropriate alkyllithium reagent, and these compounds in turn were found to react readily with CO to form the acyl complexes Rh(RCO)(CO)(triphos). Addition of anhydrous HCl to the complex RhCl(CO)(triphos) resulted in the formation of a mixture of RhHCl₂(CO)(triphos) and RhCl₃(triphos), while addition of excess chlorine, bromine, or iodine to [Rh(CO)₂(triphos)]PF₆ resulted in the formation of the rhodium(III) complexes [RhX₂(triphos)]PF₆ (X = Cl, Br, I). These reacted in turn with methyllithium to form RhMe₃(triphos), and with a variety of neutral ligands L to form the series [RhX₂L(triphos)]PF₆.