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Preparation of "Constrained Geometry" Titanium Complexes of [1,2]Azasilinane Framework for Olefin Polymerization
- Author(s)
- 이슬
- Alternative Author(s)
- Seul Lee
- Advisor
- 이분열
- Department
- 일반대학원 분자과학기술학과
- Publisher
- The Graduate School, Ajou University
- Publication Year
- 2017-02
- Language
- eng
- Keyword
- Copolymerization; Ethylene; Titianium catalyst
- Alternative Abstract
- The Me2Si-bridged ansa-Cp/amido half-metallocene, [Me2Si(n5-Me4C5)(NtBu)]TiCl2, termed a "constrained-geometry catalyst (CGC)", is a representative homogeneous Ziegler catalyst. CGC derivatives with the [1,2]azasilinane framework, in which the amide alkyl substituent is joined by the Si-bridge, were prepared, and the catalytic performances of these species was studied. Me4C5H-Si(Me)(CH2CH=CH2)-NH(C(R)(R')CH=CH2) (R, R' = H or methyl; Me4C5H = tetramethylcyclopentadienyl) was susceptible to ring closure metathesis (RCM) when treated with Schrock's Mo-catalyst to afford -Si(Me4C5H)(Me)CH2CH=CHC(R)(R')NH- containing a six-membered ring framework. Using the precursors and the products of RCM, various CGC derivatives, i.e., [-Si(5-Me4C5)(Me)CH2CH=CHC(R)(H)N-]TiMe2 (13, R = H; 15, R = Me), [-Si(n5-Me4C5)(Me)CH2CH2CH2CH2N]TiMe2 (14), [(n5-Me4C5)Si(Me)(CH2CH=CH2)NCH2CH=CH2]TiMe2 (16), [(n5-Me4C5)Si(Me)(CH=CH2)NCH2CH=CH2]TiMe2 (17), and [(n5-Me4C5)Si(Me)(CH2CH3)NCH2CH2CH3]TiMe2 (18), were prepared. The catalytic activity of the newly prepared complexes was lower than that of CGC when activated with [Ph3C][B(C6F5)4]/iBu3Al. However, the catalytic activity of these species was improved by using tetrabutylaluminoxane ([iBu2Al]2O) instead of iBu3Al and the activity of 14/[Ph3C][B(C6F5)4]/[iBu2Al]2O was comparable to that of CGC/[Ph3C][B(C6F5)4]/iBu3Al (94 and 99 x 10^6 g/molTi·h, respectively). Advantageously, the newly prepared complexes produced higher molecular weight poly(ethylene-co-1-octene)s than CGC.
- Fulltext
- Appears in Collections:
- Graduate School of Ajou University > Department of Molecular Science and Technology > 3. Theses(Master)
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