Vinyl-polymerization of norbornene with novel anilido-imino nickel complexes/methylaluminoxane: Abnormal influence of polymerization temperature on molecular weight of polynorbornenes

Polynorbornenes obtained by anilido-imino nickel complexes 1-4/MAO catalytic systems show broad and bimodal molecular weight distribution (MWD) below 50 °C, and average molecular weight of polynorbornenes increases and MWD is narrowed with the increase in the temperature. This abnormal result could be attributed to the equilibrium shift between two active species in toluene.