Next Article in Journal
Influence of Weak Base Addition to Hole-Collecting Buffer Layers in Polymer:Fullerene Solar Cells
Next Article in Special Issue
Engineering of Syndiotactic and Isotactic Polystyrene-Based Copolymers via Stereoselective Catalytic Polymerization
Previous Article in Journal
The Therapeutic Potential of Migrastatin-Core Analogs for the Treatment of Metastatic Cancer
Article Menu
Issue 2 (February) cover image

Export Article

Open AccessArticle
Molecules 2017, 22(2), 258;

Preparation of “Constrained Geometry” Titanium Complexes of [1,2]Azasilinane Framework for Ethylene/1-Octene Copolymerization

Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea
Author to whom correspondence should be addressed.
Academic Editor: Kotohiro Nomura
Received: 27 December 2016 / Revised: 1 February 2017 / Accepted: 7 February 2017 / Published: 9 February 2017
(This article belongs to the Special Issue Organometallic Catalysis for Olefin Polymerization/Oligomerization)
Full-Text   |   PDF [1914 KB, uploaded 9 February 2017]   |  


The Me2Si-bridged ansa-Cp/amido half-metallocene, [Me2Si(η5-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. Me4C5HSi(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(η5-Me4C5)(Me)CH2CH=CHC(R)(H)N-]TiMe2 (13, R = H; 15, R = Me), [-Si(η5-Me4C5)(Me)CH2CH2CH2CH2N]TiMe2 (14), [(η5-Me4C5)Si(Me)(CH2CH=CH2)NCH2CH=CH2]TiMe2 (16), [(η5-Me4C5)Si (Me)(CH=CH2)NCH2CH=CH2]TiMe2 (17), and [(η5-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 (4.7 and 5.0 × 106 g/mol-Ti, respectively). Advantageously, the newly prepared complexes produced higher molecular weight poly(ethylene-co-1-octene)s than CGC. View Full-Text
Keywords: olefin polymerization; titanium complex; constrained geometry; half-metallocene olefin polymerization; titanium complex; constrained geometry; half-metallocene

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Lee, S.; Park, S.S.; Kim, J.G.; Kim, C.S.; Lee, B.Y. Preparation of “Constrained Geometry” Titanium Complexes of [1,2]Azasilinane Framework for Ethylene/1-Octene Copolymerization. Molecules 2017, 22, 258.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top