Palladium(II) complexes containing a pyridinyliminophosphorane ligand
A series of new pyridinyliminophosphorane bidentate ligands with different steric environments [(2-C6H4N)PPh2= NAr (NPN)] and their methylpalladium complexes PdClMe(NPN)] were prepared. From the crystal structure analysis it is evident that the alkyl ligands are always trans to the pyridinyl nitrogen donor, revealing a σ-donating ability of the iminophosphorane. However, the two Pd-Cl bonds in [PdCl2(NPN)] are essentially the same length. Cationic palladium complexes catalyzed the copolymerization of norbornene/ethylene as well as CO/norbornene. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.