Talk:Quaternary ammonium cation

From Wikipedia, the free encyclopedia
Jump to: navigation, search
WikiProject Chemistry (Rated Start-class, Mid-importance)
WikiProject icon This article is within the scope of WikiProject Chemistry, a collaborative effort to improve the coverage of chemistry on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
 

Merge[edit]

Quat is a common name for this chemical species, while it is not for quaternion. I suggest merge and redirect, possibly with a {other uses} tag, though I fail to see why it would be neccessary. mastodon 18:39, 25 April 2006 (UTC)

I don't see what's wrong with having a dab page. There are other uses of the word, and I added a few. The point is to make it easier for users to find the information they want. If it's a redirect instead of a dab page, the people who are looking for Quaternary ammonium cation will get there a tiny bit faster, but the people looking for Phan Huy Quat will have to look harder. —Keenan Pepper 20:40, 25 April 2006 (UTC)

Some website (title added)[edit]

see this [1] —The preceding unsigned comment was added by 203.164.226.76 (talkcontribs) .

Yeah, what about it? —Keenan Pepper 03:48, 5 September 2006 (UTC)

Venta Airwasher[edit]

Venta Airwasher http://www.venta-airwasher.com/html/customer_service.html uses QUATERNARY AMMONIUM COMPOUNDS as additive to the water that is evaporated to humidify a room. Is this safe. They say that it does not evaporate so do not breath. —The preceding unsigned comment was added by 68.222.162.29 (talkcontribs) 18:04, 3 December 2006 (UTC).

Added term "Quaternary Amine"[edit]

The lignite article describes the addition of quaternary amines to lignite and links to this article for an explanation of what quaternary amine means.

Question[edit]

Can quats be isolated in pure (i. e. metallic) form? I know that regular ammonium can't (all attempts to produce ammonium metal have resulted in ammonia and hydrogen gases, instead, although I believe that someone did add a few ammonium cations to a mercury amalgam). Since alkyl groups aren't as easily liberated as hydrogen, maybe quats would be stable enough to exist as a "molecular metal"? Especially if they had electropositive groups like trimethylsilyl attached.

Any response would be appreciated. Stonemason89 (talk) 15:02, 12 August 2008 (UTC)

Ammonium--quaternary or not--is an ion, and ions simply cannot be isolated "pure" in a condensed phase due to the electric repulsion between them (you could have a pure beam of ions under high vacuum, but that would be an extremely small amount). Or do you mean an electrically neutral molecule such as NH4 or NR4, formed by adding an electron to the ion, NH4+ or NR4+? In that case, I know that NH4 has been formed as a Rydberg molecule, but that's an unstable species and it's not something you could actually isolate. Finally, I'm not sure what you mean when you say that "pure" ammonium should be a metal. --Itub (talk) 08:04, 14 August 2008 (UTC)
What I meant is that metals (such as aluminum, iron, etc.) don't exist as neutral atoms in their pure form (at least that's what my chemistry teacher told me); they consist entirely of cations with a "sea" of free-floating electrons to balance out their positive charges. So iron is actually Fe3+ with extra electrons shared "socialistically" between all the iron cations; these extra electrons balance out the positive charges of the ions. I was thinking of a substance consisting of NR4+ cations and an electron sea; I suppose you could also call it "tetramethylammonium electride" since the balancing negative charges would come from the delocalized electrons. All metallic solids are electrides, in that sense. So couldn't the Na+ cations in sodium metal be replaced with NR4+ cations (which are chemically similar)? It'd probably be an extremely reactive solid (like sodium metal itself) but it doesn't seem like it'd be impossible to isolate it at all. Stonemason89 (talk) 22:05, 14 August 2008 (UTC)
Oh, I see, that's an interesting question. I think the problem is that, unlike metals, all the atoms in NH4+ have full valence shells. Compare with the case of metals, which always have lots of empty orbitals in the valence shell that can contribute to the conduction band. See metallic bond for more details. --05:36, 15 August 2008 (UTC)
Ah, I see. I looked at the metallic bond article and found that my teacher was, sadly, wrong with his "electron sea" model--except in the case of cesium, which doesn't follow the conduction band model (because it is so incredibly electropositive) and instead has electrons which appear to be completely free.
NH4+ has full valence shells, so it won't attract any extra electrons (except maybe into an antibonding orbital of some kind, like in that Rydberg molecule you mentioned). Cesium doesn't attract electrons much either, so they're kind of similar in that sense; maybe they could be alloyed. The danger is that the cesium might reduce the NH4+ into nitride and hydride.
NR4+ seems more promising, especially if R is a group with unfilled, relatively low-energy nonbonding or antibonding orbitals that could contribute to the conduction band. Certain conjugated or aromatic groups might work.
Forgive me for going on like this; it's just that I'm going to start taking nanotechnology courses this fall and so I want to learn as much as I can about this kind of thing beforehand, so I don't ask my instructor too many questions (I'm a Curious George when it comes to science).
Thanks for reading my comments,
-Stonemason89 (talk) 02:41, 17 August 2008 (UTC)
Ammonium amalgams exist. Otherwise, as indicated by Itub, the closest things are probably electrides where the [cation-cryptand]+ is embedded in a material with high conductivity. And there are probably NH4+-containing intercalation cmpds with diverse electronic properties.--Smokefoot (talk) 16:50, 19 August 2008 (UTC)

{{food safety}}[edit]

I've removed this template because it is a general one which does not specifically mention this article. Adding this template seems to give an undue weight to a small aspect of this class. --Rifleman 82 (talk) 07:15, 12 September 2008 (UTC)

I agree to Rifleman. --Leyo 08:16, 12 September 2008 (UTC)