Excellent Stereoregular Isotactic Polymerizations of Propylene with C2-Symmetric Silylene-Bridged Metallocene Catalysts
- 1 October 1989
- journal article
- Published by Oxford University Press (OUP) in Chemistry Letters
- Vol. 18 (10) , 1853-1856
- https://doi.org/10.1246/cl.1989.1853
Abstract
New C2-symmetric silylene-bridged metallocene compounds, [Me2Si(η5-RnC5H4−n)(η5-R′nC5H4−n)]MCl2 (M = Zr, Hf; Rn, R′n = Me, t-Bu, 2,4-Me, 2,3,5-Me3), were synthesized together with C1-symmetric ones (M = Zr, Hf; Rn = 2,3,5-Me3, 2,4-Me2, 3,4-Me2, t-Bu, Me; R′n = Me, H) for comparison and employed as the catalysts for isotactic polymerization of propylene in combination with methylaluminoxane. The C2-symmetric metallocenes bearing methyl groups at 2- or 5-positions gave polymers of the highest melting point (160–163 °C) and stereospecificity ([mmmm]: 97–99%).This publication has 4 references indexed in Scilit:
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