Synthesis And Ethylene Oligomerization Of Late Transition Metal Catalysts

Olefin polymerization and oligomerization catalyzed by late transition metal complexes have attracted great attentions in both academic and industrial research. Late transition metal complexes are recently developed high active non-metallocene system.On the base of the investigation about the late transition metal catalysts, I designed and synthesized three novel series of iron, nickel and cobalt catalysts containting N, N or N, O, N ligands. My research work was mainly composed of four parts:In the first part, a series of new cobalt and nickel complexes L2M2X2 (M=Co or Ni, X=C1) bearing 2-(2-pyridyl)benzimidazole ligands(L) were synthesized. Treatment of the complexes L2M2X2 with methylaluminoxane(MAO) leads to active catalysts for oligomerization of ethylene with catalytic activities in the range of 5.78 103-7.50 103gC2H4/molCo-h-atm for Co complexes, and0.52 105-1.14 105gC2H4/molNi-h-atrn for the nickel complexes. The oligomers were olefins from C4 to C6.In the second part, a series of new nickel complexes LMX2 (M= Fe, Co or Ni, X=C1 or Br) bearing 2-acetylbis(imino)benzimidazole ligands(L) were synthesized. Treatment of the complexes LMX2 with methylaluminoxane(MAO) leads to active catalysts for oligomerization of ethylene with catalytic activities in the range of 1.13 104-2.01 104gC2H4/molM-h-atm for Iron and Cobalt complexes, The oligomers were olefins from C4 to C6. And catalytic activities are in the range of 0.71 105-2.58 105gC2H4/molNi-h-atm for the nickel complexes. The oligomers were olefins from C4 to C20- At the same time, some polyethylene was obtained.In the third part, a series of new cobalt complexes LMX2 (M=Co, X=C1) bearing 2,6-bis(imino)phenoxy ligands(L) were synthesized. The crystal structure of complex 3 has been determined by single-crystal X-ray diffraction study. Treatment of the complexes LMX2 with methylaluminoxane(MAO) leads to active catalysts for oligomerization of ethylene with catalytic activities in the range of 1.14 104-3.95 104gC2H4/molCo-h-atm for Co complexes. The oligomers were olefinsfrom C4 to C6.In the fourth part, a series of new cobalt and nickel complexes LMX2 (M=Co or Ni, X=C1) bearing 2,6-bis(imino)phenoxy ligands(L) were synthesized. Treatment of the complexes LMX2 with methylaluminoxane(MAO) leads to active catalysts for oligomerization of ethylene with catalytic activities in the range of 1.78 103-3.65 103gC2H4/molCo-h-atm for Co complexes, and1.98 104-4.57 104gC2H4/molNi-h-atm for the nickel complexes. The oligomers were olefins from C4 to C6.