Talk:Dichlorodifluoroethylene

three isomers

There are three different compounds named "dichlorodifluoroethylene" (1,1-, Z-1,2- and E-1,2-dichlorodifluoroethylene), but only one of them is described in the article. Either the heading of the article should be adapted to the content, or the other isomers should at least be mentioned in the article. --79.243.252.242 (talk) 21:17, 31 August 2013 (UTC)

What's the third isomer? There doesn't seem to me to be any possibility of stereoisomers, but that seems to be what you are suggesting. I could be wrong. See #Article scope and name below. Andrewa (talk) 20:57, 21 December 2013 (UTC)

And I was wrong, it seems to be a classic case, similar to 1,2-Dichloroethene. The three are now all mentioned.[1] Andrewa (talk) 14:52, 25 December 2013 (UTC)

Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: not moved. Andrewa (talk) 14:41, 21 December 2013 (UTC)

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Dichlorodifluoroethylene → R-1112a – concur with foregoing talk: the article title is ambiguous, referring not to the single chemical substance identified, but to a set of chemical isomers, making the presentation of information and physical properties for one isomer simply incorrect; the article created after the move should redirect from "1,1-dichloro-2,2-difluoroethylene". Offered by professional chemist and registered editor, LeProf. --Relisted.  — Amakuru (talk) 14:37, 13 December 2013 (UTC) 50.179.92.36 (talk) 10:57, 5 December 2013 (UTC)

• Oppose the article is ostensibly about all Cl2F2C=C structures, not just 1,1-dichloro-2,2-difluoroethylene. This would ostensibly cover 1,2-dichloro-1,2-difluoroethylene, while R-1112a only covers the prior case, and only for uses as a refrigerant. Even if we reduce the scope of this article to cover just the earlier case, it should be called 1,1-dichloro-2,2-difluoroethylene instead of the opaque R-number, as the systematic chemical name is clear as to what it is. -- 65.94.77.150 (talk) 02:38, 6 December 2013 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Article scope and name

Suggest in view of the discussion above that the scope of the article be expanded to match the name. I note that the above move was opposed for other reasons than just this alternative possible resolution. Andrewa (talk) 14:41, 21 December 2013 (UTC)

Done. [2] It would still be good for a better student of chemistry than I to review the article, I dropped out of chemistry after high school (class of 1970) but was keen up until then.

In particular, are there any isomers of C₂Cl₂F₂ not of the form 1,1-dichloro-2,2-difluoroethylene, but instead of the form 1,2-dichloro-1,2-difluoroethylene? I think there must be, otherwise there wouldn't be any isomers of dichlorodifluoroethylene at all. Hmmm, on reflection, despite the article saying series, I think these are the only two isomers of dichlorodifluoroethylene. Andrewa (talk) 15:06, 21 December 2013 (UTC)

I have boldly put what understanding I do have into the article.

My main worry is still, does 1,2-dichloro-1,2-difluoroethylene exist at all? The above discussion, and the article as I found it, both assume it does. But many substances that can be named don't and can't exist, such as my favourite (and personal invention) neononanone aka 2,2,4,4-tetrmethyl-3-pentanone (draw it).

It's a simple question you'd think. But if it doesn't, then dichlorodifluoroethylene doesn't have any isomers (ie there's only one form).

Heads-up posted for one possible expert, and possibly also the RM nominator. [3] Andrewa (talk) 15:42, 21 December 2013 (UTC)

They have replied [4]. Andrewa (talk) 21:27, 22 December 2013 (UTC)

Assuming the 1,2 case does exist, it would obviously be worth a short section, at least saying whether or not it has stereoisomers (see #three isomers above).

And if not, the article needs considerable rephrasing, and perhaps even a reconsideration of the above RM (note the perhaps, I'm not by any means convinced of this, it needs a good look at the evidence through the lens of WP:AT first.) Andrewa (talk) 00:26, 23 December 2013 (UTC)

MSDS

Work needed on what the article says about the MSDS.

Some revision of the sources for physical data, and an infobox for 1,2 are also needed.

Google produces a lot of extraneous hits. Dichlorodifluoroethene -Dichlorodifluoromethane -Wikipedia MSDS is the best I've done, and it still complains that one search term is misspelled. Some useful links:

• http://www.guidechem.com/product/search_C2Cl2F2_w-formula-p1.html names and isomers
• http://www.guidechem.com/dictionary/en/79-35-6.html basic safety information on 1,1
• http://www.guidechem.com/msds/79-35-6.html MSDS for 1,1
• http://en.chembase.cn/ViewMolInfo.aspx?molid=8944 some physical details for 1,1
• http://hazmap.nlm.nih.gov/category-details?id=9830&table=copytblagents safety details on 1,1

Watch this space! Andrewa (talk) 20:49, 27 December 2013 (UTC)

Alkene?

Article is flagged as a stub, and in one of the two stub templates as an article about an alkene. Not sure that's quite correct, it's a related compound and a halogenated alkene but not itself an alkene as I understand the term.

But I could be wrong. See Talk:Alkene#Definition and Wikipedia talk:WikiProject Chemistry#Definition of alkene. Andrewa (talk) 21:52, 27 December 2013 (UTC)

"Alkene" is the most appropriate stub category. Plasmic Physics (talk) 09:51, 30 December 2013 (UTC)

Why?

Please note that the article is already flagged as an organic halide stub. Surely that's a better stub category? Why do we need the second?

And if we do, then we need to rephrase the sub notice, so as to conform to the IUPAC definitions. [5] [6] Andrewa (talk) 12:51, 30 December 2013 (UTC)

I've fixed that - now it's no longer tagged as an organohalide. (Compounds that do not contain C-H bonds should not have organo- stub templates due to contestability of 'organic' definition, as was decided). The sub notice is under the Chemistry WikiProject's jurisdiction, take it up with them. Plasmic Physics (talk) 21:36, 30 December 2013 (UTC)

Actually, it's not technically a single compound - so an 'alkene stub' is no good either. I've changed it accordingly. Plasmic Physics (talk) 05:13, 1 January 2014 (UTC)

It should yet be flagged both as an alkene and as an organohalide. That it is a set of isomers, rather than a discrete organic should not make a difference. And the "organic" moniker does not require the presence of a C-H bond, though hydrocarbon-containing organics are by far the most prevalent of organics. (I know of no practicing organic chemist that would not consider this set of haloalkenes to be organic, and it is organic chemists that discovered them, make them, use them, etc. Who might be wrong here?) As for "alkenes": all alkenes share common structure and reactivity (to a point), based on the sp2 centers of the C-C double bond. Adding halogens make them haloalkenes, a subset of alkenes with modified behaviour (but alkenes nonetheless). LeProf

Andrewa doing a great job ...

... other will / should address as time permits. Cheers, HNY. LeProf. — Preceding unsigned comment added by 50.179.245.225 (talk) 20:08, 5 January 2014 (UTC)