Synthesis,Structure and Norbornene Polymerization Catalyzed by Nickel(Ⅱ) Complex Bearing N,O-bis(1-(6-ethylpyridin-2-ylimino)-methylenyl)naphthalen-2-ol Ligand

The title complex bis{1-{[(6-ethyl-2-pyridinyl)imino]methylenyl}-2-naphthalenolato-N,O}-nickel(Ⅱ)(C36H32N4O2Ni) has been synthesized by the reaction of 1-{[(6-ethyl-2-pyridinyl)imino]methylenyl}-2-naphthalenol with Ni(CH3COO)2·4H2O, and characterized by IR spectrum, elemental analysis and TG. The complicated space structure has been confirmed by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 11.410(4), b = 14.382(4), c = 18.121(6) , β = 97.147(6)°, V = 2950.5(16) 3, C36H32N4O2Ni, Mr = 611.37, Z = 4, Dc = 1.376 g/cm3, μ = 0.698 mm-1, F(000) = 1280, the final R = 0.0519 and wR = 0.1493(Ⅰ 2δ(Ⅰ)). This title compound was used as precatalysts for the polymerisation of norbornene. When activated with MAO, the complex exhibited excellent catalytic activity up to 1.98 × 107 g of PNB(mol of Ni)-1 h-1 with high monomer conversion.