| 초록 |
The Polymethylene bridged dinuclear half-sandwich constrained geometry catalysts (DCGC) [Zr(η5:η1-C9H5SiMe2NCMe3)Me2]2[(CH2)n] [n=6(13), 9(14), 12(15)] have been prepared by treating four equivalents of MeMgBr with the corresponding compound [Zr(η5:η1-C9H5SiMe2NCMe3)Cl2]2[(CH2)n] [n=6, 9, 12]. Proton, Carbon-13 NMR spectra and Element Analysis of the synthesized complexes provide firm evidence for the anticipated structure objectives. In order to investigate the catalytic behaviors of the prepared dinuclear catalyst, the ethylene polymerization and ethylene/1-hexene copolymerization were conducted using B(C6F5)3 or Ph3CB(C6F5)4 or Ph3C(C6F5)3BC6F4B(C6F5)3Ph3C as a cocatalyst at 30℃. All the catalyst systems gave polymers. The prime observance is that their activities increase in the order of 13 ＜ 14 ＜ 15 which indicates the presence of longer bridge between two active sites contributes to facilitate the polymerization activity of the dinuclear CGC. From the 13C NMR studies we could identify compositions as well as sequencies of the copolymer. |
