215818-31-8Relevant academic research and scientific papers
Preparation of doubly-silylene-bridged zirconocene alkyl complexes, (Me2Si)2{η5-C5H 2-4-CHMe2}{η5-C5H-3,5-(CHMe 2)2}ZrR2(R = CH3, CH2Ph) and investigations of their activity in 1-pentene polymerization.
Veghini, Dario,Day, Michael W.,Bercaw, John E.
, p. 226 - 232 (1998)
The syntheses of the doubly-[SiMe2]-bridged zirconocene complexes, (Me2Si)2{η5-C5H 2-4-CHMe2}{η5-C5H-3,5-(CHMe 2)2}ZrR2 (R = Cl (2); R = CH2Ph (3); R = CH3 (4)) are described. The structure of (Me2Si)2{η5-C5H 2-4-CHMe2}{η5-C5H-3,5-(CHMe 2)2}-Zr(CH2Ph)2 (3) has been examined by single crystal X-ray diffraction methods. It crystallizes in the triclinic space group P-1, with a = 9.900(2), b = 11.818(2), c = 15.320(3) A?, α = 105.02(3), β = 92.56(3), γ = 105.23(3)° and Z=2. Compounds 3 and 4 are active stereospecific pre-catalysts for the [Ph3C] [B(C6F5)4] co-catalyzed polymerization of 1-pentene. Polymerization reactions at low temperature in liquid monomer produced poly(1-pentene) with syndiotactic microstructure and narrow molecular weight distribution. By contrast, in 1-pentene/toluene solutions a broad molecular weight distribution is observed. Under all conditions examined 2/MAO systems produced high molecular weight, highly syndiotactic poly-1-pentene with narrow molecular weight distributions.
