A series of nickel complexes {NOONR}Ni（A： R=Me; B： R=t-Bu; C： R=OMe） based on salicylalde- hyde-imine ligands was synthesized through Schiff base condensation and metal complexation reaction. Upon activation with...A series of nickel complexes {NOONR}Ni（A： R=Me; B： R=t-Bu; C： R=OMe） based on salicylalde- hyde-imine ligands was synthesized through Schiff base condensation and metal complexation reaction. Upon activation with methylalurninoxane（MAO）, nickel complexes A--C all exhibited good catalytic activity[turnover frequency=5.2×10^5-16.3×10^5 g/（mol Ni-h）] and oligomer selectivity（above 85%, mass fraction） in ethylene oligomerization. In addition, C8--C12 olefins occupied an important proportion in the products of oligomers. Under the conditions of 4.0 MPa, 25℃ and A1/Ni molar ratio of 275, the catalytic selectivity of A/MAO system toward C8-C12 was about 30. 1%（mass fraction）, and the content of C8--C12 a-olefins was consistently above 70%. Furthermore, besides the ligand environment, the catalytic properties of A-C were substantially affected by experimental parameters, such as the reaction pressure, reaction temperature and A1/Ni ratio.展开更多
文摘A series of nickel complexes {NOONR}Ni（A： R=Me; B： R=t-Bu; C： R=OMe） based on salicylalde- hyde-imine ligands was synthesized through Schiff base condensation and metal complexation reaction. Upon activation with methylalurninoxane（MAO）, nickel complexes A--C all exhibited good catalytic activity[turnover frequency=5.2×10^5-16.3×10^5 g/（mol Ni-h）] and oligomer selectivity（above 85%, mass fraction） in ethylene oligomerization. In addition, C8--C12 olefins occupied an important proportion in the products of oligomers. Under the conditions of 4.0 MPa, 25℃ and A1/Ni molar ratio of 275, the catalytic selectivity of A/MAO system toward C8-C12 was about 30. 1%（mass fraction）, and the content of C8--C12 a-olefins was consistently above 70%. Furthermore, besides the ligand environment, the catalytic properties of A-C were substantially affected by experimental parameters, such as the reaction pressure, reaction temperature and A1/Ni ratio.
