Talk:N-Butyllithium

Structure Images

The structure pictures in this article are not accurate. The substance forms a much more complex oligomer in solid and solution phases. I commented out two of these pictures. I left in the "ionic" structure as it is commonly used by organic chemists to describe the reactivityof the substance. If anybody has a public domain image to show the real structure, or even a link to a good one somewhere, that would be great.

Reacts with Water?

The article text says that this compound "reacts violently with water", but the NPFA 704 thing in the sidebar does not show the W symbol. Are these both correct? --Jonadab, 2007 Mar 17

Its reaction with water is energetic enough to ignite it or its solvent. T-butyllithium bursts into flame in air. --Vuo 18:03, 19 March 2007 (UTC)

Halogen-Lithium Exchange

Since a previous edit brought up the question of side reactions in the halogen-lithium exchange, I expanded the section to give a more realistic view of the limitations, particularly for the preparation of vinyllithium reagents. For a look at how vinyllithiums are actually prepared in the laboratory, see the vinyllithium section in the following web site: http://www.chem.wisc.edu/areas/reich/Handouts/lireagents/index-orgli.htm. Much more information on uses of BuLi in organic synthesis can also be found in the Keyword and Reagents indices on this web site: http://www.chem.wisc.edu/areas/reich/syntheses/syntheses.htm (these web sites are both my work)

In my view, butyllithium is such an important chemical that it deserves a much more extensive coverage than this little article. ChemistHans 22:02, 15 August 2007 (UTC)

Your edits are welcome and more expert than most of us are capable. Many reagents are very poorly understood in terms of what they are vs. what they do. It took a while to convince editors that NaH was not soluble. SImilarly, only recently did the ionic structure for Li⁺Bu^- disappear from this article. WE-chem still doesnt have have anything on KOBu-t. And I cannot find mention in any textbook for the products of BuLi + O₂: this basic reaction is rarely described as it is apparently not useful in organic synthesis.--Smokefoot 00:36, 16 August 2007 (UTC)

The products of n-BuLi + O₂ -> n-BuOLi (mainly), and commercial n-BuLi is almost always contaminated with a little (occasionally even a lot) of n-BuOLi. This is not a useful reaction -- much cheaper ways to get n-BuOLi and n-BuOH, although with other RLi it is sometimes utilized. ChemistHans 22:40, 16 August 2007 (UTC)

[Agreed, this page is limited given the utility of BuLi. Is there an argument for creating an article for each of n-, sec- and t- ? (This may be a bit much though unless much more specialist info is added. Though seperate sections discussing each, and thus a full review of the header might be worthwhile as the reactivity/methodologies and handling of these reagents differs considerably.) Oh and I recently rejigged the safety section at the bottom with respect to what Vuo wrote above, I hope it reads ok. Not much on Schlosser's base, or all his work on exhaustive aryl substitution patterns.]

Yes, I think t-BuLi certainly deserve its own article (the german Wikipedia has one started for t-BuLi, they call it tert-Butyllithium http://de.wikipedia.org/wiki/Tert-Butyllithium). As you said, t-BuLi needs to be handled much more carefully, and has some very specific important uses where nothing else will do. On my total synthesis web site I mentioned above, t-BuLi has almost as many entries as does n-BuLi. Because of its expense and the greater hazard in handling, it is almost never used where n-BuLi can do the job. s-BuLi is a little less important, but a short description would be appropriate. I'll give it some thought, although I am not so clear in my mind how far Wikipedia-Chemistry wants to go into the details. ChemistHans 22:40, 16 August 2007 (UTC)

There is a starter on sec-Butyllithium.--Smokefoot 22:45, 16 August 2007 (UTC)

I also found a stub on t-BuLi at: http://en.wikipedia.org/wiki/Tert-butyllithium. However, a search of Wikipedia does not locate tert-Butyllithium, and when I fixed the spelling of a t-BuLi link in the n-BuLi article, it does not register the link. Anyone know what the story is here? ChemistHans 23:26, 16 August 2007 (UTC)

I think that I fixed that link - I had misnamed t-BuLi with a lower case b. There is some sort of hang-up at Wikipedia about the first letter always being capitalized, which I have never bothered to figure out. Many of the n-,o-,m-, p--whatever organic compounds suffer from this issue. Probably someone, some time will fix it.--Smokefoot 23:36, 16 August 2007 (UTC)

Metalation

The equation for reaction with butyllithium with R-H to give R-Li, while in principle reversible, is in actual practice, virtually never so. I propose that the reversible arrows be replaced by a right-arrow. ChemistHans 00:11, 19 August 2007 (UTC)

Crystal structure?

I read in this paper from 1990 that the crystal structure of n-BuLi has not been determined. Is this still true?

Ben (talk) 23:16, 1 May 2008 (UTC)

No, See: STRUCTURES OF CLASSICAL REAGENTS IN CHEMICAL SYNTHESIS - (NBULI)6, (TBULI)4, AND THE METASTABLE (TBULI.ET2O)2 Author(s): KOTTKE T, STALKE D Source: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH Volume: 32 Issue: 4 Pages: 580-582 Published: APR 1993 Times Cited: 122

The n-BuLi crystallized as a hexamer from pentane; the melting point was found at -34, (older literature claimed -76; maybe polymorphs, or plainly wrong?). In any case, BuLi is a liquid at room temperature (not a solid, as the wikipedia article says). —Preceding unsigned comment added by 134.130.101.232 (talk) 12:19, 8 May 2008 (UTC)

Had a look at this paper (DOI link here) but crystal structure data only available through the Cambridge Structural Database, and because the paper is pre-1994, the data is not easily available from the CCDC - although this is likely to change.

Ben (talk) 15:27, 17 November 2008 (UTC)

I can send you the .cif file with the crystal structure if you want; just send me an email. --Itub (talk) 13:47, 18 November 2008 (UTC)

Lithium Hydride?

The article implies butyl lithium degrades to lithium hydride (the white precipitate). Uh well as a chemist I will have to challenge this. Someone show me the mechanism by which it does this. Or did they mean Lithium hydroxide? I can tell you this, when BuLi comes into contact with "water" in the air, it goes to lithium hydroxide. I can't imagine it going to Lithium hydride over time in the bottle. —Preceding unsigned comment added by 72.194.216.17 (talk) 08:02, 17 November 2008 (UTC)

Beta-hydride elimination to alkene and lithium hydride. --Vuo (talk) 08:21, 18 November 2008 (UTC)

External links modified (February 2018)

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Stoichiometry

Hi folks. I am not by any stretch a chemist (though I have on more than one occasion been promoted temporarily into that capacity being the only one in a room full of engineers and physicists foolish enough to admit to having some memory of my chem 101), but looking at the illustrations of n-BuLi, I see an assembly whose stoichiometric formula, for both the tetra and hexamer, comes out to C4H9Li2, so please could someone explain (in the article itself would be nice, for non-wizards like myself trying to gain some entry to the arcana) how the formula is computed to be C4H9Li?172.103.138.179 (talk) 11:42, 16 August 2018 (UTC)[Just an occasional wiki grammar editor, but more often a student of the world of information found here.]

In the illustrations for both the tetramer and the hexamer, the ratio of butyl groups (C4H9) to lithium atoms is 1:1 so the formula comes out to C4H9Li in each case. -- Ed (Edgar181) 11:53, 16 August 2018 (UTC)

Superbase that is electron deficient?

In the article it states that n-buLi is electron deificient so it readily reacts with lewis bases. How is this true if n-BuLi is itself a superbase? It should be highly reactive towards Lewis acids, no? — Preceding unsigned comment added by Crlhermitte (talk • contribs) 01:58, 21 January 2020 (UTC)

Lewis acidity is related to electron deficiency. Basicity is related to the energy of the HOMO. This thing has got both going on. It needs electrons (it = "Li⁺" part) and t-Bu "anion" has high energy valence electrons. --Smokefoot (talk) 12:59, 21 January 2020 (UTC)