A SF(5) Derivative of Triphenylphosphine as an Electron-Poor Ligand Precursor for Rh and Ir Complexes

The synthesis of the triarylphosphine, P(p-C(6)H(4)SF(5))(3) containing a SF(5) group, has been achieved. The experimental and theoretical studies showed that P(p-C(6)H(4)SF(5))(3) is a weaker σ-donor when compared with other substituted triarylphosphines, which is consistent with the electron-withdrawing effect of the SF(5) moiety. The studies also revealed a moderate air stability of the phosphine. The σ-donor capabilities of P(p-C(6)H(4)SF(5))(3) were estimated from the phosphorus-selenium coupling constant in SeP(p-C(6)H(4)SF(5))(3) and by DFT calculations. The behavior of P(p-C(6)H(4)SF(5))(3) as ligand has been investigated by the synthesis of the iridium and rhodium complexes [MCl(COD){P(p-C(6)H(4)SF(5))(3)}], [MCl(CO)(2){P(p-C(6)H(4)SF(5))(3)}(2)] (M = Ir, Rh), or [Rh(µ-Cl)(COE){P(p-C(6)H(4)SF(5))(3)}](2), and the molecular structures of [IrCl(COD){P(p-C(6)H(4)SF(5))(3)}] and [Rh(µ-Cl)(COE){P(p-C(6)H(4)SF(5))(3)}](2) were determined by single X-ray diffraction. The structures revealed a slightly larger cone angle for P(p-C(6)H(4)SF(5))(3) when compared to other para-substituted triarylphosphines.