Some addition compounds of chlorobis(triphenylphospine)iridium(I)

Abstract

The synthesis and properties of chlorobis(triphenylphospine)iridium(I), IrCl(PPh 3) 2, and some of its addition products are reported. With ethylene, IrCl(C 2H 4)(PPh 3) 2 is formed. Indications have been found pointing to the formation, at low temperature, of the unstable bis(ethylene) adduct IrCl(C 2H 4) 2(PPh 3) 2. With one equivalent of allene, IrCl(C 3H 4)(PPh 3) 2 is formed. The reaction product with excess of allene is IrCl(C 6H 8)(PPh 3) 2, in which the 2,2′-bi-σ,π-allyl ligand is present. In the presence of an excess of ethylene, IrCl(C 2H 4)(PPh 3) 2 forms with molecular oxygen IrCl(C 2H 4(O 2)(PPh 3) 2, in which ethylene can be replaced by other ligands. With sulfur dioxide, IrCl(C 2H 4)(PPh 3) 2 and IrCl(C 3H 4)(PPh 3) 2 form the adducts IrCl(C 2H 4)(SO 2)(PPh 3) 2 and IrCl(C 3H 4)(SO 2) (PPh 3) 2. The stability of five-coordinated compounds of the type IrCl(PPh 3) 2XY is discussed on the basis of the donor and acceptor properties of the ligands X and Y.