Six complexes of two series were studied as the catalyst precursors for CO/ethylene copolymerization by using catalytic evaluation method and EXAFS technique.The first series of the complexes has general formular (L)Pd(OCOCF3)2 in which L is DPPPr,DPPBu or DPPEt.The second series of the complexes has general formular (DPPPr)Pd(A)2 in which A-is CF3COO-,P-CH3PhSO3-,Cl-or CH3COO-.The results showed that suitable ligands have relatively strong coordination ability to palladium(Ⅱ) center.Suitable anoins belonging to strong acids,have excellent stability on cationic palladium(Ⅱ),and easy to leave away to give coordination vacant to comonomers.
