Talk:Ziegler–Natta catalyst

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Mechanism[edit]

why is the C in the middle bonded to two Hs at first and only one later?

I don't think it has two Hs at first. it wouldn't work with valence either —Preceding unsigned comment added by FelixP (talkcontribs)

You are right, there seem to be some mistakes in the picture. But I think there should be two (the activator is diethylaluminiumchloride, ethyl groups on aluminum), the binding to the metal center is an agostic bond (electrons of the bond between C and H are donated into empty metal centre bonds). --Dirk Beetstra T C 13:41, 2 August 2006 (UTC)

I am not so sure if there are mistakes here - anyway its a proposed mechanism. I suspect that the Ti-CR3-Al interactions are like those in the Al-CH3-Al interactions in trimethyl aluminium. BTW: we now have agostic complex started.--Smokefoot 22:08, 2 August 2006 (UTC)

Under the topic -Heterogeneous catalysts the line that states -"The preferred carrier is microporous spheres of amorphous silica with a diameter of 30–40 mm." Seems to be incorrect. As a size of 30-40mm would be quite large in the terms of chemistry. A reference supporting this size would be needed as most literature gives sizes in the nm range. — Preceding unsigned comment added by 50.128.240.186 (talk) 18:54, 1 December 2013 (UTC)

Is this the "Ziegler Process"?[edit]

I am curious if this catalyst is what makes the "Ziegler Process"? Maury 16:31, 19 March 2007 (UTC)

Truly a C-grade Wikipedia Article[edit]

This is perhaps the first article I have come to with a "C" grade, and it is richly deserved. Those who have posted this material should themselves look for colleagues able to write the broad introduction present in better articles and missing here. I would suggest separating treatment of 50 year old Ziegler-Natta liquid-and-metal catalysts, which began by breaking carbon double-bonds to get molecule chaining (polymerization) started, from later developments. Deal separately with metallocene catalysts having engineered shapes that controlled isotactic and syndiotactic sequencing of the growing chain. That separation gives us a chance for a simpler treatment of polymer chain basics -- getting them started -- in an introduction that comes to isotactic and syndiotactic issues separately, explicitly, and later on. Mentioning milestone historic developments in the field would organize the intro and aid the entry overall; mention John A. Ewen and metallocene advances in the early 1990s. Exxon's attempt to crush him, and the lawsuit and conviction he won against Exxon in 1995 would add some spice and illustrate the high stakes here, wouldn't they?
--jerry
Jerry-va (talk) 18:56, 20 October 2011 (UTC)