A number of cyclometalated palladium(II) complexes [PdCl(pyC6H4)(L)] containing amino-pyridine or acetylamino-pyridine co-ligands (L) have been prepared from the reaction of [Pd(pyC6H4)(μ-Cl)]2 with two equivalents of these ligands. Crystal structures of four examples have been carried out, each showing a distorted square planer geometry around palladium with the amino- or acetylamino-pyridine ligand being coordinated via nitrogen atom and lying almost perpendicular to the square-plane. Similarly, [PdCl(pyC6H4)(κ1-dppmO)] and [PdCl(pyC6H4)(κ1-dppeO)] result from reactions of [Pd(C6H4py)(μ-Cl)]2 with Ph2PCH2P(O)PPh2 (dppmO) and Ph2PCH2CH2P(O)PPh2 (dppeO) respectively. Here the phosphine ligand is attached via only phosphorus, however, removal of the chloride upon addition of AgNO3 lead to the formation of [Pd(pyC6H4)(κ2-dppmO)][NO3] and [Pd(pyC6H4)(κ2-dppeO)][NO3] in which the ligands are believed to bind in a chelate fashion.
