Talk:Haloalkane

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This article is a merger of generic arcticles Alkyl halide, halocarbon, Freon, Halon, CFC, and HCFC. Several other general articles redirect to these four, e.g., HFC. This new merged article primarily tries to present the chemical compounds, and gives the environmental issues a fair touch. The specific chemical products, focussing on one chemical compound each, such as tetrachloromethane are not merged into this article. There is a lot still to do on it, but this is a start. Feel free to dig in. Wim van Dorst 20:26, 2005 May 29 (UTC).


Ozone Destruction[edit]

"CFCs' lack of reactivity gives them a lifespan which can exceed 100 years in some cases. This gives them time to diffuse into the upper stratosphere. Here, the sun's ultraviolet radiation is strong enough to break off the chlorine atom, which on its own is a highly reactive free radical. This catalyzes the break up of ozone into oxygen..."

Now we all know this, but how do the CFC's disperse into the atmosphere? Are they lighter than air? Can they gather enough energy to make it all the way into the upper stratosphere? I can't find the density of a CFC molecule anywhere on the web. --68.158.211.169 (talk) 20:15, 16 October 2008 (UTC)

Comment on union of articles[edit]

I'm wondering if it was worth joining all these articles together into one article. If it was up to me, I would have had

(1) a general Haloalkane article including the chemistry aspects and maybe the "naming code",

(2) another article on Refrigerants combining Freons, CFC's, and HFC's discussing the refrigeration, air conditioning, and perhaps thermodynamic aspects, and

(3) a third article on Halon.

I think there was enough material for three decent articles. It was the "name coding" scheme that was largely redundant in those three articles. Eliminating the redundancies and appropriate links could have fixed that. However, I think I'm making this comment too late. I thought this was Cacycle's pet project and that he's been dormant for the past month and a half. There is also an article called refrigerant which also lists the "naming code" again. Maybe the information on haloalkanes can be incorporated into this article.

If one considers polyethylene, branched polyethylene, polypropylene, etc. to be alkanes, then partially or completely halogenated versions would fall under haloalkane. Perhaps, the existence of such halogenated polymers ought to be mentioned here, with whatever appropriate links there are. H Padleckas 10:58, 30 May 2005 (UTC)

Actually, I quite agree with you, Henry: The reason for merging was that there were five totally overlapping articles, each covering mostly the same material. The recommendation for merging was listed on all article pages, and in my opinion rightly so.
  • The merged article is this one, which needs a little more developing to become your (1). For obvious reasons, I redirected the original articles all into the merged article.
  • Then indeed information about refrigerants really warrants an article of its own (2). The current article is very overlapping again, so I didn't include it in the merge (it doesn't add anything). Contrarily, I left it alone to make a stepping stone for someone bold enough to work on it to improve it to make your proposal (2). I (or somebody else bold enough) probably will be shifting some info from the merged articles to it, to make a start there.
  • The former halon article wasn't a chemical article at all, but a good article about fire extinguishing gas. Comparable as for the refrigerant application, I support the recommendation of the former halon talk page to copy the interesting data (and pictures) into the application fire extinguisher#Halons section (correct text currently in there, and a better title perhaps?).
Additionally to the overall information in the haloalkane page, I think some more chemical pages could still reasonably be created (it is never to late), e.g., a chlorofluoroalkane for CFC, HCFC and HFC compounds, and a bromofluoroalkane about the halon compounds. Important is to make appropriate linking, avoiding future double (or worse contradictory) information in all of them.
And yes I did read all comments, including proposals, such as Cacycle's, giving direction to the merge, and in my humble opinion (at least my intention) followed them. Wim van Dorst 19:54, 2005 May 31 (UTC).
I have tried to avoid getting embroiled in this, but I feel I should weigh in with my comments. It was clearly necessary to remove a lot of duplication and perhaps the best way was to start with a merge. I agree with Henry, though, there should be several articles- and after the split someone should "police" them to make sure someone doesn't start adding Freon names to an unrelated page. I would avoid putting in a lot of stuff on CFCs & HFCs etc on the haloalkanes page, and keep it more like this Wikibook article in terms of content area. Walkerma 16:13, 16 Jun 2005 (UTC)
As for the name of this article, Cacycle preferred Alkyl halide over halocarbon, and I would prefer that too, as it is in more common use among chemists I know, at least for things with only one halogen like iodomethane (methyl iodide). In a "poll" of six recent editions of US college organic textbooks on my shelf, four called the chapter alkyl halides, one called them haloalkanes, and one called them alkyl halides (haloalkanes). I don't have strong feelings on this, however. Things like aryl halides and vinyl halides are always awkward to classify. Walkerma 16:13, 16 Jun 2005 (UTC)

I came here looking for info on Freon and, apart from general CFC information, am given a grand total of one sentence, which is going to lead me on a long google trawl. Please split this article so that the sections can naturally accumulate information. Having redudant information is not a huge problem. Having no information is. Quirkie 21:34, 23 April 2007 (UTC)

R-134 and R-134a[edit]

According to the "naming code", R-134 should be the most symmetrical version of C2H2F4, namely 1,1,2,2-tetrafluoroethane. R-134a should be a less symmetrical version of C2H2F4, namely 1,1,1,2-tetrafluoroethane, which is the new Freon replacement we've all come to know and love. ;-) I believe the Suva name would be consistent with that. If there's no response in a couple of days, I think I'll go and fix it myself. H Padleckas 11:09, 30 May 2005 (UTC)

Changes to Haloalkanes Table[edit]

I made some changes to the haloalkanes table. My computer monitor screen is not very wide. I made the table wider so that all the chemical formulas in the rightmost column could fit on one line. If you don't like some change, revert it. H Padleckas 17:19, 1 Jun 2005 (UTC)

  • Good changes! Please do more. Wim van Dorst 20:46, 2005 Jun 1 (UTC).

If it's worse, just revert, but I changed the table so that the links are just in the first column. I made redirects for some of the systematic names that didn't have them. I left the red links that were already made in the first column, but I didn't make new ones for the entries that had other names red linked. -- Kjkolb 08:19, 16 December 2005 (UTC)

Dodgy Characters[edit]

Anyone know what the problem is with the unreadable characters? I'm on XP and tried IE and Firefox with no joy. Is this an OCR or copy paste problem? What should those formulae be?? Regards SeanMack 16:13, 9 April 2006 (UTC)

Mind if you can tell us which characters are unreadable? The article turns out fine to me. 203.124.2.20 17:44, 12 August 2006 (UTC)

"Canned air" / arrangement of article / legality[edit]

Is the use of hydrochlorofluorocarbons legal? Everywhere? I'm specifically wondering about canned air, which I haven't heard of outside the US. Am I justified in adding a note to the canned air page that it's not that environmentally friendly?

On page arrangment, it's overwhelming, and there are double redirects back to chlorofluorocarbon. It's confusing to be taken to a long article about haloalkanes on typing in 'CFCs,' and a bit like being redirected to a page on 'mammals' when typing in 'dog.'

(I'm not criticising anyone's merges/demerges as I don't have time to edit the article myself right now or even read all the comments above.)

Njál 20:14, 1 June 2006 (UTC)

Global Warming?[edit]

If somebody has the time & background, the environmental effects section should be updated to include climate change effects (radiative forcing, etc.) Perhaps it can go in the general halocarbons article. I'm not familiar enough with the chemistry/physics to put it together.

Yeah, I ran across articles that said some HFCs were horrendous greenhouse gases -- something like 17,000 times more effective in that regard than CO2. Not quite sure what to make of such comments, some clarification here from those with the know would be appreciated. MrG 4.228.21.75 19:34, 12 June 2007 (UTC)

I honestly think it's not even worth debating... I wish there was some way to include the fact that water vapor is not only a more influential greenhouse gas than any other gas but is by far the most abundant. Are CFC's really an influence on the O-zone and global warming? Maybe... but the sher mass of water vapor in our atmosphere makes CFC's and even Co2 irrelevant. Who cares whether or not we affect it... if we do influence it is the cost really worth trying to fix what we can? That's just my opinion on the o-zone and global warming. Does it mean anything about the science of the article... not really... just food for thought to editors or whoever happens to read this.
TheHoustonKid

Nice try, HoustonKid, but your Jedi mind tricks will not work on us ... water vapor in the atmosphere, at least when it collects into clouds, is a cooling factor on the Earth. MrG 4.225.210.106 (talk) 15:10, 11 June 2008 (UTC)

Synthesis[edit]

From Alkanes

It does not make any sense to me why is there only the Initiation Step, but not the termination step. The free radical halogenation/substitution (whatever you call it), consist of Initiation, Propagation and Termination steps. If possible, please include the last step to make the reaction complete.

From Alkenes

I made a slight edit on the second example to mkae it a more balanced equation. 203.124.2.55 17:53, 12 August 2006 (UTC)

"Dibromochloropropane" or "2-Bromo-1-Chloropropane"[edit]

I need to know if "2-Bromo-1-Chloropropane" is the same as "Dibromochloropropane".

Randreed 18:22, 5 February 2007 (UTC)

2-bromo-1-chloropropane will be ClCH3CHBrCH3 while dibromochloropropane will be C3H5Br2Cl. So, not the same. --Rifleman 82 19:50, 5 February 2007 (UTC)

What is halon?[edit]

One consequence of the merger has been that the word "halon" is used without being introduced or defined. As a non-chemist coming to this page to read about halon, it's a bit confusing. It sounds like a halon is some type of haloalkane. Or maybe it's a trade name? (It seems so, according to http://en.wikipedia.org/wiki/Bromotrifluoromethane) It would be helpful to have a brief gloss. —The preceding unsigned comment was added by Huttarl (talkcontribs) 11:25, 14 March 2007 (UTC).

Where Does HFA-134a Fit?[edit]

By all the information I can gather it is the same as the HFC-134a in context but the pharmaceutical companies refer to it as HFA-134a (1,1,1,2-tetrafluoroethane). Is it a purity standard?

--RonEJ 09:30, 25 March 2007 (UTC)

Citations/References[edit]

Several references appear at the end of the page, but few are actually referred to in the article. I've refrained from tagging anything as unreferenced; I'd prefer to either start a discussion about this or call it to the attention of someone who is bolder than I. The "Environmental issues" section especially needs these direct references, as this part is commonly debated.

Also noted is the shortage of peer-reviewed, scientific articles in the reference section. 71.96.69.173 23:23, 15 May 2007 (UTC)

Alkyl halides...[edit]

Whilst haloalkanes are all alkanes, it is very important to remember that alkyl halides include all possible aliphatic and sundry organic molecule. For example 1-bromo-2-butyne is an alkyl halide despite being an alkyne. chloromethyl benzene for eg is also one. The CFC's etc sections are fantastic but perhaps a little misleading. The redirect from alkyl halide could be sent to organic halides. This would be better.... Spgoo1 04:15, 3 October 2007 (UTC)

An addition to the Chloro fluoro compounds section[edit]

I am thinking about adding a little more information about how chlorofluorocarbons actually deplete the ozone layer. This addition should provide some background on why ozone depletion is happenning as well as the consequences of this depletion--Ilikemangos (talk) 06:54, 18 March 2008 (UTC)

Question: Amount[edit]

Has anyone data on the total amount (e.g. in tons) of CFC use commercially? I believe a statistic of "production in tons/year" over the relevant period and "estimated tons set free per year" would be an excellent addition to this article. If possible, of course with proper links to authentic data. Cheers! —Preceding unsigned comment added by 84.143.99.99 (talk) 13:17, 30 April 2008 (UTC)

Question: HFC Abbreviations[edit]

The article isn't clear on the use of abbreviations of "Hydro fluoro compounds" / "Hydrofluorocarbons", sometimes the abbreviation is written HFCs, sometimes HFC (a third variant is HFC's, c.f. PFC (chemical)). I am no native speaker, but since the "C" stands for "compounds"/"carbons" shouldn't the abbreviation be just HFC? —Preceding unsigned comment added by 193.174.171.2 (talk) 13:57, 23 March 2009 (UTC)


Project Delaware?[edit]

This is an article on a class of organic chemicals, why is it part of the aformentioed project? Obikirk (talk) 15:01, 2 February 2010 (UTC)