Synthesis and characterization of tridentate phenoxy‐imine ligand [ N , N , O ] nickel(II) and palladium(II) complexes and their catalytic behaviors in vinyl polymerization of norbornene

In this study, new complexes LNiCl( 1 ), LNiBr( 2 ), LNiI( 3 ), and LPdCl( 4 ) (L = 4,6‐di‐ tert ‐butyl‐2‐( N ‐(quinolin‐8‐yl)iminomethyl)phenolato) have been synthesized and characterized. X‐ray diffraction studies on Complexes 1 and 4 revealed that N, N, O, and halogen atoms coordinated to metal, with a nearly square planar geometries in all cases. All these complexes are robust and exhibit high activities for the addition polymerization of norbornene (NB) with methylaluminoxane as cocatalyst [up to 47.62 kg PNB(mmol of Ni) −1 h −1 ] and also lead to various activities and molecular weights of polynorbornenes under different reaction conditions. It is noteworthy that Complexes 1 and 4 show better activity under higher reaction temperature of 80°C. However, Complex 2 showed lower activity, and Complex 3 was found nearly inert toward NB polymerization, probably, because of thermal instability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009