caa a22 4500 475761987 CHVBK 20180406123554.0 cr unu---uuuuu 170329e20000201xx s 000 0 eng 10.1007/BF02494677 doi (NATIONALLICENCE)springer-10.1007/BF02494677 Effect of substituents on the catalytic properties of bis(cyclopentadienyl)zirconium dichloride complexes with polymethylaluminoxane and AlBu1 3/CPh3B(C6F5)4 cocatalysts in ethylene polymerization [Elektronische Daten] [A. Panin, O. Babkina, N. Bravaya] The catalytic properties of the complexes (RCp)2ZrCl2 (R=H, Me, Pri, Bun, Bui, Me3Si,cyclo-C6H11), and Me2SiCp*NBuiZrCl2 (Cp*=C5(CH3)4) combined with the AlBui 3−CPh3B(C6F5)4 cocatalyst in ethylene polymerization were studied. The specific activity of the substituted bis-cyclopentadienyl complexes decreases in the sequence: Me>Pri>Bun>Bui>Me3Si>cyclo-C6H11, which corresponds to the activity sequence for these complexes activated by polymethylaluminoxane (MAO) but is 4-20 times lower in absolute value. Comparison of the polyethylene samples obtained in the presence of the same complexes with MAO and AlBui 3−CPh3B(C6F5)4 cocatalysts showed that polyethylene with much higher molecular mass, melting point, and crystallinity is formed in the presence of the ternary catalytic systems, and this indicates a different nature of the active sites of the catalytic systems. The effective activation energy of polymerization (≈3.6 kcal mol−1), first order with respect to monomer and ≈0.4 order with respect to organoaluminum component, was found for the (PriCo)2ZrCl2−AlBui 3−CPh3B(C6F5)4 catalytic system. It was proposed on the basis of the kinetic data that AliBu3 enters into the composition of the active site to form a bridged heteronuclear cationic complex. Kluwer Academic/Plenum Publishers, 2000 metallocene catalysts nationallicence zirconocenes nationallicence ethylene polymerization nationallicence kinetics of polymerization nationallicence active site nationallicence perfluorophenyl borates nationallicence polymethylaluminoxane nationallicence effect of substituents nationallicence Panin A. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432, Chernogolovka, Moscow Region, Russian Federation aut Babkina O. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432, Chernogolovka, Moscow Region, Russian Federation aut Bravaya N. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432, Chernogolovka, Moscow Region, Russian Federation aut Russian Chemical Bulletin Kluwer Academic Publishers-Plenum Publishers 49/2(2000-02-01), 303-309 1066-5285 49:2<303 2000 49 11172 https://doi.org/10.1007/BF02494677 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02494677 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Panin A. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432, Chernogolovka, Moscow Region, Russian Federation aut NATIONALLICENCE 700 1- Babkina O. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432, Chernogolovka, Moscow Region, Russian Federation aut NATIONALLICENCE 700 1- Bravaya N. Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432, Chernogolovka, Moscow Region, Russian Federation aut NATIONALLICENCE 773 0- Russian Chemical Bulletin Kluwer Academic Publishers-Plenum Publishers 49/2(2000-02-01), 303-309 1066-5285 49:2<303 2000 49 11172 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer