In this study, new complexes LNiCl(1), LNiBr(2), LNil(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 polynorbomenes under different reaction conditions. It is noteworthy that Complexes 1 and 4 show better activity under higher reaction temperature of 80 degrees C. However, Complex 2 showed lower activity, and Complex 3 was found nearly inert toward NB Polymerization, probably, because of thermal instability. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 1642-1650, 2009