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- W2040891107 abstract "The imido complexes CpV(N-2-MeC6H4)Cl2 (1), Cr(N-tBu)2Cl2 (2), CpNb(N-2-tBuC6H4)Cl2 (3) and Mo(N-tBu)2Cl2 (4) have been tested as procatalysts for the polymerisation of ethylene in combination with diethylaluminium chloride or methylaluminoxane (MAO) co-catalysts. The vanadium precursors give the highest activities but are short-lived, while the chromium system gives a long-lived catalyst of moderate activity. The niobium and molybdenum derivatives gave relatively low activities under all test conditions. The polyethylene generated by the vanadium and chromium catalysts is of high molecular weight with little branching. The dialkyl complexes Cr(N-tBu)2(CH2Ph)2 (5), Cr(N-2,6-Pri2C6H3)2(CH2Ph)2 (6), Cr(N-2,6-Pri2C6H3)2Me2 (7), Mo(N-tBu)2(CH2Ph)2 (8), Mo(N-2,6-Pri2C6H3)2(CH2Ph)2 (9), (C5Me5)Nb(N-2,6-Pri2C6H3)Me2 (10) and (C5Me5)Ta(N-tBu)(CH2Ph)2 (11) have been prepared by treatment of the dihalide precursors with appropriate alkylating reagents and investigated as precursors to well-defined cationic alkyl catalysts. Treatment of (5) with [Ph3C][B(C6F5)4] affords the cationic η2-benzyl species [Cr(N-tBu)2(η2-CH2Ph)][B(C6F5)4] (12) while its reaction with [PhNMe2H][B(C6F5)4] liberates toluene to give a mixture of the mono and bis(dimethylaniline) adducts [Cr(N-tBu)2(η2-CH2Ph)(NMe2Ph)][B(C6F5)4] (14) and [Cr(N-tBu)2(η2-CH2Ph)(NMe2Ph)2][B(C6F5)4] (15). Complex 12 reacts with trimethylphosphine to give the mono-phosphine adduct [Cr(N-tBu)2(η2-CH2Ph)(PMe3)][B(C6F5)4] (13). Solutions containing cationic species (12, 14, 15) are active for ethylene polymerisation in the absence of co-catalyst, affording high-molecular-weight polyethylene with relatively broad molecular-weight distributions." @default.
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- W2040891107 date "1999-12-01" @default.
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- W2040891107 title "Transition metal imido catalysts for ethylene polymerisation" @default.
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- W2040891107 cites W1986989732 @default.
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- W2040891107 cites W1993593636 @default.
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- W2040891107 cites W2029359904 @default.
- W2040891107 cites W2029442115 @default.
- W2040891107 cites W2036665297 @default.
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- W2040891107 doi "https://doi.org/10.1016/s0022-328x(99)00452-0" @default.
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