Rhodium complexes containing the hybrid P,O ligand PPh2NHC(O)Me or its anion, [PPh2NC(O)Me]–Dedicated to Dr Jean-Marie Basset on the occasion of his 60th birthday, with our congratulations and best wishes.

Abstract

The coordination behaviour of the heterofunctional phosphine ligand PPh₂NHC(O)Me towards Rh(I) is reported and examples of neutral and cationic complexes containing mono- or bi-dentate modes of coordination are found. The X-ray structure of [Rh{PPh₂NHC(O)Me}(CO)Cl]·CH₂Cl₂ (1·CH₂Cl₂) shows that the P,O-chelate is almost planar and coplanar with the Rh(I) square-plane. An unusual example of coordination is found in the dimer [Rh{μ-PPh₂NC(O)Me}(CO)]₂ (2), which contains the bidentate, anionic ligand that bridges two rhodium atoms via the oxygen; it is probable that the neutral ligand can form similar complexes, such as 11 and 12. Displacement of the P,O ligand by CO or RNC ligands occurs in 1 but not in 2.