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By treating disodium(thiophenedirnethylene)dicyclopentadienide C_4H_2S(CH_2C_5H_4Na)_2 with two equivalent of CpTiCl_3 or CpZrCl_3 DME at 0℃ in THF,two new thiophenedimethylene bridged binuclear metallocenes [Cl_2MC_5H_5][C_5H_4CH_2C_4H_2SCH_2C_5H_4][C_5H_5MCl_2](M=Ti 3,M=Zr 4)were synthesized in high yield and their structures were characterized by ~1H-NMR.These complexes were used as catalysts for ethylene polymerization in the presence of methylaluminoxane(MAO).The effects of polymerization temperature,time,concentration of catalyst,molar ratio of MAO/Cat on polymerization were studied in detail.The catalytic activities of thiophenedimethylene bridged binuclear metallocene catalysts(3,4)reached 2.44×10~5 g PE mol~(-1)·cat~(-1)·h~(-1),9.61×10~5 g PE mol~(-1)·cat~(-1)·h~(-1) respectively,which are higher than that of pheneyldimethylene bridged binuclear metallocene catalysts and much higher than that of corresponding mononuclear metallocenes(Cp_2TiCl_2 and Cp_2ZrCl_2).The molecular weight distribution curves of polyethylenes produced by binuclear metallocene catalysts(3,4)and by mononuclear metallocene catalyst have only single peak,but the former(MWD=3.5-4.7)is obviously broader than the latter(MWD=2.0-2.2).
Two thiophenediriethylene bridged binuclear metallocenes [Cl_2MC_5H_5] [C_5H_4CH_2C_4H_2SCH_2C_5H_4] [C_5H_5M_4] (M = Ti 3, M = Zr 4) were synthesized in high yield and their structures were characterized by ~ 1H-NMR. These complexes were used as catalysts for ethylene polymerization in the presence of methylaluminoxane (MAO). The effects of polymerization temperature, time, concentration of catalyst, molar ratio of MAO / Cat on polymerization were studied in detail. The catalytic activities of thiophenedimethylene bridged binuclear metallocene catalysts (3,4) reached 2.44 × 10 ~ 5 g PE mol ~ (-1) cat ~ (-1) · h ~ ( -1), 9.61 × 10 ~ 5 g PE mol ~ (-1) · cat ~ (-1) · h ~ (-1) respectively, which are higher than that of pheneyldimethylene bridged binuclear metallocene catalysts and much higher than that of corresponding mononuclear metallocenes (Cp_2TiCl_2 and Cp_2ZrCl_2) .The mole cular weight distribution curves of polyethylenes produced by binuclear metallocene catalysts (3,4) and by mononuclear metallocene catalysts have only single peak, but the former (MWD = 3.5-4.7) is obviously broader than the latter (MWD = 2.0-2.2).