Catalysis Letters, Vol.139, No.3-4, 90-96, 2010
Bis(Pyrazolyl)Pyridine Late Transition Metal Complexes as Single-Site Catalysts for Ethylene Polymerization to Highly Linear Polyethylene
The synthesis, characterization of the halide complexes LMX (n) (M = Co (1), Fe (2); X = Cl; n = 2); (M = Ni (3), X = Br, n = 2) bearing 2,6-bis(3,5-dimethylpyrazol-1-ylmethyl)pyridine ligand (L) and ethylene polymerization behaviour of these complexes are described. Complexes 1-3 display reasonable activity for ethylene polymerization on treatment with activated methylaluminoxane (MAO), produce single-site catalysts that polymerized ethylene to highly linear polyethylene (PE). Molecular weights (M (w)) of the polymers produced are in the range (0.7-1.4) x 10(6) g mol(-1) with relatively narrow molecular weight distribution (2.1-2.8).