Wikipedia talk:WikiProject Chemicals/Archive 2019

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Merge request at Talk:Nitric acid

See Talk:Nitric_acid#Merge_back_red_fuming_nitric_acid_and_white_fuming_nitric_acid_into_this_article. Chemists with expertise in this area welcome. Thanks, shoy (reactions) 13:42, 19 February 2019 (UTC)

Discussion you may be interested in if this is your area of expertise.

Please see Talk:2010–2017 Toronto serial homicides#"Amyl nitrate". We could use some additional voices, especially those with more knowledge of chemistry. Thanks. --Jayron32 17:28, 14 February 2019 (UTC)

Requests for comment are sought at Talk:2010–2017 Toronto serial homicides § RfC on drug name on how to state the name of a drug mentioned in court documents about a living person. – Reidgreg (talk) 16:31, 26 February 2019 (UTC)

WP 1.0 Bot Beta

Hello! Your WikiProject has been selected to participate in the WP 1.0 Bot rewrite beta. This means that, starting in the next few days or weeks, your assessment tables will be updated using code in the new bot, codenamed Lucky. You can read more about this change on the Wikipedia 1.0 Editorial team page. Thanks! audiodude (talk) 06:48, 27 February 2019 (UTC)

Propionic vs propanoic

I am passing on a note left at Talk:Propanoic acid because it raises a general question: "Traditional name favoured over preferred IUPAC name? This is something that has been bothering me about this page for some time. For most organic compounds Wikipedia uses the preferred IUPAC name for the page title, but for propanoic acid (and a few of its derivatives/related compounds), the traditional name with the "propio" prefix is used. Surely we should be consistent with how we decide upon which name to favour on articles and in titles, particularly since the preferred IUPAC names are likely to become the most commonly used names over time? Trainer Alex (talk) 15:31, 8 March 2019 (UTC)"

• I vote that we keep this page title as Propionic acid.--Smokefoot (talk) 16:24, 8 March 2019 (UTC)

Predicament in the area vinyl ethers

I am consulting colleagues about a naming issue. Here is the situation that temporarily bothers me (a little):

• Divinyl ether is a relatively obscure organic compound that once attained prominence as an anesthetic at one time. The article about this compound should be divinyl ether, but instead divinyl ether redirects to vinyl ether (interestingly, I can find hardly any articles about divinyl ether as a reagent).
• Vinyl ether is any of a large class of enol ethers. That name should direct to enol ether (or the reverse). Instead vinyl ether is an article about divinyl ether. So people seeking info about a medium-sized topic (vinyl ethers, enol ethers) are sent to an obscure one (divinyl ether).
• Enol ethers should be a more encompassing article.

--Smokefoot (talk) 02:03, 13 April 2019 (UTC)

Thank everyone for helping out. Unless I hear objections or someone else wants to do this, I will cut and paste most of the content in vinyl ether into divinyl ether, then convert vinyl ether into a redirect to enol ether.--Smokefoot (talk) 10:25, 13 April 2019 (UTC)

That sounds like a good solution. I agree that the niche compound article should not be the WP:PRIMARYTOPIC for the ambiguous term "vinyl ether", but that instead the functional group is. And having the redirect from the ambiguous to the primary-topic's actual page is obviously consistent. DMacks (talk) 13:40, 13 April 2019 (UTC)

Organosilicon reorg?

Here is a proposal for the reorganization of our articles on organosilicon and hydrosilicon compounds. First of all, we have organosilicon (thank you V8rik).

• Binary silicon-hydrogen compounds a proposed re-labled article about Si_xH_y (Si analogues of alkanes) Done
  • Currently Silanes, which is too vague
  • except for SiH₄, these are mainly of academic interest, things like disilane (Alfred Stock's work)
• Organohydrosilane (seems clumsy)
  • Useful compounds R_3-nSiH_n (n ≥ 1), e.g. triethylsilane, triethoxylsilane
  • Currentlyretaining silyl hydride, which seems too vague. Done
• What to do with R₄Si (R = organyl)?
  • Perhaps covered by organosilicon
  • Start an article on carbosilanes, which is currently a category?
• Alkoxysilanes R_4-xSi(OR')_x
  • We probably need to start this
  • Possibly silanization could be part of such an article
• Chlorosilanes
  • The article on HSiCl₃ (has a chembox) is currently a catch-all for compounds containing Si-Cl bonds.
  • To do: separate HSiCl₃ vs the general class. Done
• Silicones is stable.
• siloxane is ok. (the distinction vs silicone is not 100% clear: the latter are molecular and the former are often crosslinked?).

I will be fairly inactive for a few days, so I am in no rush. Anyway, maybe this proposal is too specialized for most folks. --Smokefoot (talk) 02:00, 22 April 2019 (UTC)

Proteins

Should we include proteins in the scope of the Chemicals Project. Should articles like Zingibain be tagged as belonging to Chemicals? Or should we just tag them for MCB? Most of the information for proteins would be described in a different way and a different infobox is used, not Chembox. If they are out, should we untag proteins for WP Chemicals? Graeme Bartlett (talk) 22:22, 12 April 2019 (UTC)

I would say we should untag them when we see them. They are so different from "chemist" chemicals. Christian75 (talk) 22:17, 22 April 2019 (UTC)

Proposal of Importance Scale in template:WikiProject Chemicals

The importance scale in template:WikiProject Chemicals can be determined by the number of literatures. For example, scale "low" is <100 literatures, "mid" is 100~999, "high" is 1000~9999 and "top" is 10000 or more than 10000. There are 202391 literatures about acetone and 17336 literatures about barium chloride, thus these two chemicals can be classified as top importance. For tetrabromoauric acid, only 99 hits, therefore low importance.--Leiem (talk) 05:52, 20 April 2019 (UTC)

@Leiem:Can you clarify a few things? How are you reading "number of literatures"? Is that based on hits in SciFinder, or Reaxys, or something else? Are you searching by structure, or CAS#, or InChI? Things are never perfect with these things, unfortunately; with structure, there may be several ways to write a structure. With CAS#, this will only work if people have access to SciFinder, and InChI doesn't always work well with things like organometallics. Thanks, Walkerma (talk) 11:08, 28 April 2019 (UTC)

@Walkerma:(1) We can use the maximum number. If someone only has access to one database and find 100 hits, he can use "100 hits". Then others may find 200 hits, they can update 100 to 200. (2) Either is OK. The maximum number will be recorded. (3) If one article describes more than one structure (enantiomers, etc.), then the number is the sum of them. Thanks for response. --Leiem (talk) 02:24, 29 April 2019 (UTC)

ChemConnector Returning to Wikipedia after a hiatus - Chemistry Curation AGAIN

After a long hiatus away from Wikipedia, other than some minor contributions, I am returning to my work that I engaged in previously with people like DMacks, Walkerma, Beetstra to curate chemistry and chemical compounds. Now, because of my work with the CompTox Chemicals Dashboard I believe that, because of the greater level of curation of the data (full time curators working daily to improve the data quality) and the focus of the database rather than simply assembling the largest database (875k as of April 2019 versus 71 million for ChemSPider and 91 million for PubChem) I believe that our data quality is much higher. I have been able to identify 15,010 unique inorganic and organic chemical compounds to date on Wikipedia (excluding polymers at present). My intention is to provide as many systematic names, SMILES, InChIStrings and InChIkeys as possible for all chemicals so that a comparison exercise with what is presently in the Drug and ChemBoxes can be done. I can tell that there are already incorrect SMILES and InChIs for a number of chemicals and would like to clean this up if possible AND finally provide a single source of Wikipedia Chemicals in SDF format that can be downloaded, modeled, profiled, etc. For example this is a SUBSET : WIKILIST: Additives in cigarettes but I am building a series of these: WIKILIST: Extremely hazardous substances.

I am looking to see whether anyone in Wikipedia Chemicals world would be willing to help me harvest Names and CASRN to associate with Wikipedia Chemical articles and ChemBox/DrugBox so I can continue the work of building the definitive file? If anyone is interested please post on my Talk Page. ChemConnector (talk) 23:57, 19 April 2019 (UTC)

I would also like to comment that the CompTox Chemicals Dashboard identifier, the DTXSID, has been approved by Wikidata. I think it would be beneficial to add links into the Dashboard from the ChemBoxes and DrugBoxes because of the available toxicity data that we have for tens of thousands of chemicals, for example, Atrazine. ChemConnector (talk) 02:59, 21 April 2019 (UTC)

Discussion about adding parameters |DTXSID= (redacted, DePiep) is at Talk:Chembox. -DePiep (talk) 09:31, 21 April 2019 (UTC)

Both {{Chembox}} and {{Infobox drug}} will have |DTXSID= added, linking to the dashboard page (aspirine example). By default, DSSTox substance ID (P3117) is read from Wikidata, and is locally overwriteable. I'd strongly advise that for this parameter, curation happens at Wikidata. -DePiep (talk) 10:45, 22 April 2019 (UTC)

@ChemConnector: Working on a similar task in Wikidata. My advice: don't use Wikipedia articles as basis to generate a list of chmicals. Often some WP articles mix information about salt forms with acid form of a chemical, or the stereoconfiguration is not well defined. To generate a list of chemicals, I am using InChIKey as primary identifier and my idea is to use that ID to compare datasets from several reference databases from which I can extract other IDs. Then a comparison will be performed to detect discrepancies between the different databases for the same ID. Snipre (talk) 22:00, 28 April 2019 (UTC)

I sympathise with Snipre's approach. Good to learn that InChIKey is the preferred pin-key (not CASnr etc. then). A pity enwiki and wikidata do not synchronise in data definition -- yet. Recently, in this topic, I have advised ChemConnector to start at Wikidata for mass-checking and -curating identifiers. -DePiep (talk) 22:18, 28 April 2019 (UTC)

If some people are interested, please have a look at ChemID Initiative. Snipre (talk) 00:19, 29 April 2019 (UTC)

@Snipre: @DePiep: Just this weekend I identified that the Domoic acid on Wikidata was different from the Domoic Acid on Wikipedia. I edited the Domoic acid on Wikipedia years ago yet the Wikidata has the OLD structure from years ago. I edited the InChIKey and SMILES on WIkidata to the correct form to match the Wikipedia article. Unfortunately I am seeing issues with InChIKeys not matching the structures and SMILES without stereochemistry when there should be stereo. Also, InChI does NOT support enhanced stereochemistry so chemicals such as toxaphene should not have SMILES? I looked at the ChemID Initiative and it looks very interesting indeed. I am willing to participate and help. I have a lot of experience of comparing across multiple databases and unfortunately there are many collisions. It would good to expand on this - should I simply add comments to the ChemID initiative or would you prefer offline to email??? Snipre, can you share a list of InChIKeys with associated WIkipedia article names and preferably associated CASRNs too? ChemConnector (talk) 02:48, 29 April 2019 (UTC)

@ChemConnector: Welcome in the world of mixed data: Wikidata was filled 4-5 years old ago with data from several wikipedias based on the interwikis. But nobody checks if the interwikis were well defined so we have many wrong match between data. For toxaphene, data are mixed from toxaphene (chemical substance) and octachlorocamphene. Since this import we are trying to curate manually the data, but for this we focus first on items having constraint violations (i.e. two IDs defined as unique,...). And we reduced as much as possible imports from Wikipedia to avoid to add more errors.

I corrected toxaphene by splitting the data of 1,4,5,6,7,7-hexachloro-2,2-bis(chloromethyl)-3-methylidenebicyclo[2.2.1]heptane (in a new item (see here)) from the chemical substance.

DTXSID added to the WIkidata recordChemConnector (talk) 11:54, 29 April 2019 (UTC)

We are only 3-5 active contributors in the Wikiproject Chemistry in WD and I am the only one concerning by the ID problem, so expect to join an active team. If you plan to work in a similar work to ChemID, just put your comment in the talk page. Snipre (talk) 09:51, 29 April 2019 (UTC)

Looking forward to it. I just need to figure out how to contribute to your ongoing project and not waste time starting my own efforts.ChemConnector (talk) 11:54, 29 April 2019 (UTC)

@ChemConnector: A little overview of the different databases used by WD: [1]. Snipre (talk) 09:57, 29 April 2019 (UTC) Thanks - I know Egon personally and appreciate his work and activities. ChemConnector (talk) 11:54, 29 April 2019 (UTC)

@DePiep:I have submitted the page for review today. Feedback welcomed and maybe it is appropriate to move this over now to Production but I will not make that call: https://en.wikipedia.org/wiki/Draft:CompTox_Chemicals_Dashboard ChemConnector (talk) 20:57, 29 April 2019 (UTC)

Diphenylacetylene is an alkyne derivative?

Diphenylacetylene seems like an alkyne to me. DMAD is not an alkyne? Some other eyes might look at this new categorization. Seems misguided, or at least unconventional.

And here is the scary part: "And I prefer to go with the exact classical definitions. ... And I expect the same by filling categories. I'd like to follow chemical nomenclature as close as possible" -JWBE --Smokefoot (talk) 12:07, 14 May 2019 (UTC)

Fun fact, according to the IUPAC definition cyclopentyne isn't an alkyne (because it is cyclic). A rather neat example of why we don't take such things as gospel. We've had incidents like this before, it's well meant but the categorisation chemicals can be very fuzzy. --Project Osprey (talk) 13:58, 14 May 2019 (UTC)

Please have a look, that commons:Category:Alkyne derivatives was created even in 2010, commons:Category:Alkene derivatives in 2006 and en:Category:Alkene derivatives in 2017. So it is consequent to create en:Category:Alkyne derivatives, it's very systematic. JWBE (talk) 18:38, 14 May 2019 (UTC)

We are assured that your application of nomenclature is "systematic". That justification has been laid on these pages for many years by determinedly well-intentioned editors who seek to set the record straight and cure our evil ways. The question to be pondered is deeper: is the usage useful, convenient, helpful to readers, etc. I just think that such ventures, invariably started with good intentions, should proceed with a modicum of consensus. --Smokefoot (talk) 23:53, 14 May 2019 (UTC)

What exactly is the application of the question here? Is it whether DMAD should be in Category:Alkynes vs Category:Alkyne derivatives? It's up to us as editors to decide what is an appropriate level of categorization. We could even decide that this distinction (if there is one) does a disservice to readers by making it harder to find analogous compounds from a given lead article and therefore instead we should only have one cat. I note that we currently parallel the three-way split on commons:

• Category:Alkynes—commons:Category:Alkynes
• Category:Alkyne derivatives—commons:Category:Alkyne derivatives
• Category:Alkynyl groups—commons:Category:Alkynyl groups

However, we have them with Alkynes as the parent of the other two, whereas commons has them as siblings. If you have a lot of time and wish to see 132KB of people beating their heads against a wall in a similar situation, see Wikipedia talk:WikiProject Chemistry/Archive 28. DMacks (talk) 04:36, 15 May 2019 (UTC)

MSDS at sciencelab.com offline

The MSDS pages at sciencelab.com are not available anymore:

• Special:LinkSearch/*.sciencelab.com
• insource:/\.sciencelab\.com/

--Leyo 08:37, 17 June 2019 (UTC)

Αlpha-Aminonaphthalene listed at Redirects for discussion

An editor has asked for a discussion to address the redirect Αlpha-Aminonaphthalene. Please participate in the redirect discussion if you wish to do so. The RfD discussion is here, re "α" vs "Alfa" in a title. -DePiep (talk) 00:13, 9 July 2019 (UTC)

I redirected it. Seems noncontroversial.--Smokefoot (talk) 01:36, 9 July 2019 (UTC)

Error messages but no maintenance category

I noticed that there are error messages in the GHS section of Lead titanate. However, they do not seem to trigger any maintenance category. Shouldn't they? --Leyo 08:14, 17 July 2019 (UTC)

{{Chembox}} input uses templates {{H-phrases}} and {{P-phrases}} (good).

{{Chembox
| HPhrases = {{H-phrases|302+332|360Df|373|410}}
| PPhrases = {{P-phrases|201|261|273|304+340+312|308+313|391}}
}}

However, these can not handle the |302+332| input, and create the error message. On top of this, the error message is presented in a {{abbr}} construct, showing worse. Working on an improvement; checking whether that input value is OK by itself. -DePiep (talk) 08:42, 17 July 2019 (UTC)

H302 + H332 is a combination that is contained in Annex III of the CLP regulation. The English text is Harmful in contact with skin or if inhaled. --Leyo 09:40, 17 July 2019 (UTC)

 Fixed

Created Category:GHS errors (1), for both H- and P-phrases. Erroneous input is shown but not as an abbr (no mousehoover text). In Preview, an error message is shown (try Lead titanate).

Not done: unknown codes (like |302+332|) should be added/corrected in the H, P text lists (see Template:GHS phrases format#Texts). Is there a source that lists them all?

OK? -DePiep (talk) 10:38, 17 July 2019 (UTC)

Looks good, except that the update of the templates is pending. --Leyo 15:30, 17 July 2019 (UTC)

Yes, no error message and the H/P number is showing plainly. In the link you gave I could not find easily (not at all) a list that simply says: "number 123 = en:phrase ABC". Can you take care of these text edits? BTW, some phrases take an argument, like "(lungs)". Should we add that option to these parameters? Input could look like |312(lungs)|324|. -DePiep (talk) 18:14, 17 July 2019 (UTC)

Well, the texts are contained in the consolidated version of the CLP regulation in (multilingual) tables. I am not aware of a “lazy” way to extract them.

For the purpose of our articles, I would only consider the numbers but not further specifications. They are often missing in databases etc. anyway. --Leyo 21:09, 17 July 2019 (UTC)

Oh, and there are also E123 numbers (E=environment risk)? -DePiep (talk) 18:15, 17 July 2019 (UTC)

I am not sure what you are talking about. --Leyo 21:09, 17 July 2019 (UTC)

I could not find the de:wiki templates re GHS, to steal ideas get inspired. A suggestion? -DePiep (talk) 18:17, 17 July 2019 (UTC)

• de:Vorlage:GHS-Piktogramme/Daten (with de:Vorlage:GHS-Piktogramme/Daten)
• de:Vorlage:H-Sätze (with de:Vorlage:H-Sätze/Texte, de:Vorlage:H-Sätze/Format)
• de:Vorlage:EUH-Sätze (with de:Vorlage:EUH-Sätze/Texte, de:Vorlage:EUH-Sätze/Format)
• de:Vorlage:P-Sätze (with de:Vorlage:P-Sätze/Texte, de:Vorlage:P-Sätze/Format)
• de:Vorlage:CLH-ECHA and de:Vorlage:CL Inventory for generation of reference to ECHA

--Leyo 20:55, 17 July 2019 (UTC)

Solanesol

Request article creation for the chemical Solanesol. QuackGuru (talk) 07:51, 21 July 2019 (UTC)

Solanesol needs checking from colleagues. The request for QuackGuru: see if you can edit without adding primary sources.--Smokefoot (talk) 16:58, 21 July 2019 (UTC)

References

I added a source that anyone can copy the content as long as the black box is kept inside the citation. QuackGuru (talk) 19:18, 21 July 2019 (UTC)

@QuackGuru: Have you checked WP:COI? --Smokefoot (talk) 20:33, 21 July 2019 (UTC)

Checked WP:COI for what? See "The authors declare no conflicts of interest." QuackGuru (talk) 20:37, 21 July 2019 (UTC)

COI is asking, do any of the writers on Wikipedia have any connection with the authors, or monetary interest in the subject? It is OK to have it, but if one is being paid to do stuff here it must be declared. Graeme Bartlett (talk) 21:26, 21 July 2019 (UTC)

Good to know. QuackGuru (talk) 21:51, 21 July 2019 (UTC)

Smokefoot is tough on authors citing their own work on Wikipedia especially in order to promote it. Graeme Bartlett (talk) 01:23, 22 July 2019 (UTC)

I plead guilty of that tendency. But at least QuackGuru got this article off the ground. --Smokefoot (talk) 01:47, 22 July 2019 (UTC)

It is pretty obvious my interest in this article being created has to do with tobacco. QuackGuru (talk) 06:23, 22 July 2019 (UTC)

See "Solanesol is the organic compound with the formula Me2C=CHCH2(CH2C(Me)=CHCH2)8OH.[citation needed]" I tried to find a source to verify this claim. QuackGuru (talk) 06:23, 22 July 2019 (UTC)

You can derive the descriptive formula from the picture. I did not see any reference that described the formula in that way, but it appears to be correct. I added the reference to ChEBI where the structure and name are listed. Graeme Bartlett (talk) 08:31, 22 July 2019 (UTC)

Someone could contact them and submit the Solanesol formula for this page. QuackGuru (talk) 09:05, 22 July 2019 (UTC)

Some of these chemical indexes eventually discover the Wikipedia article and link to it. With ChemSpider, I think there even might be some people around here that can add the entry. Anyway the contact there is quite responsive to anything I say to them. With PubChem I get back the answer "not our problem" and blame the sources without fixing anything. Another problem is WP:CITEGENESIS where some info goes from Wikipedia to an external site, and then the Wikipedia article references that site. Graeme Bartlett (talk) 10:09, 22 July 2019 (UTC)

Without citing Wikipedia, someone could ask them what is the formula for Solanesol. QuackGuru (talk) 16:10, 22 July 2019 (UTC)

Need structure diagram: 4-Hydroxyphenylacetaldehyde

Resolved

Thanks. Seppi333 (Insert 2¢) 06:13, 8 August 2019 (UTC)

Dimethyl ether data page

Hello! I was looking for the vapor pressure of dimethyl ether, and I found a helpful table on the data page created by this group. I think that the information here (https://webbook.nist.gov/cgi/cbook.cgi?ID=C115106&Mask=4&Type=ANTOINE&Plot=on#ANTOINE) may help improve it. There is also a link on the NIST page for the original article from 1941.

I've never edited anything on wikipedia before. So, sorry if I did this incorrectly! And if there's anyone in charge, please feel free to delete this. Thanks! Rlsans (talk) 20:06, 17 August 2019 (UTC)

Acene

Do the first two substances in the table really belong to the acenes? --Leyo 15:47, 19 August 2019 (UTC)

IUPAC defines it as File:Acenes general structure.svg with n≥1 (need to have at least two rings to have fused rings):

• IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "acenes". doi:10.1351/goldbook.A00061

so naphthalene but not benzene. DMacks (talk) 18:11, 19 August 2019 (UTC)

With n=1, I get anthracene, not naphthalene. --Leyo 08:13, 20 August 2019 (UTC)

Crap, yeah. Looking at a different (!IUPAC) diagram. n=1 is indeed anthracene, so naphthalene should also be removed. DMacks (talk) 14:32, 20 August 2019 (UTC)

Deletion of benzene and naphthalene Snipre (talk) 13:47, 20 August 2019 (UTC)

Need help

By comparing different databases about (+)-Epibatidine or Epibatidine, I found discrepancies for the name of 2 stereoisomers:

InChIKey	PubChem	CHEMBL	Drugbank	ChemIDplus	Guide to Pharmacology Ligand ID	Reaxys	ChemSpider
NLPRAJRHRHZCQQ-IVZWLZJFSA-N	(-)-Epibatidine	(-)-EPIBATIDINE	(+)-epibatidine	Epibatidine	-	epibatidine (6633501)	(+)-Epibatidine
NLPRAJRHRHZCQQ-UTLUCORTSA-N	(+)-Epibatidine	(+)-EPIBATIDINE	-	-	(+)-epibatidine	(-)-epibatidine (5811732)	(-)-Epibatidine

For some databases NLPRAJRHRHZCQQ-IVZWLZJFSA-N is (+)-Epibatidine, for others it is (-)-Epibatidine. Who is right ? Snipre (talk) 07:53, 28 August 2019 (UTC)

Problematic Categories

User:The Nth User has been doing a lot of work recently on categorising chemical compounds. Along the way they've categorised about 4000 compounds and created some 200 new cats. The majority of that work appears to be in good order but enough of it is wrong that I have concerns. I've been in touch with the editor and they appear to be holding-off from further categorisation for the time being. Some examples:

• Category:3-hydroxypropenals and Category:Lactims are wrong in that they don't contain examples of the title groups (at least as you would normal think it).
• Category:Conjugated dienes is hopelessly large but Category:3-(5,6,7,8-tetrahydro-(1,3)dioxolo(4,5-g)isoquinolin-5-yl)-3H-2-benzofuran-1-ones is incredibly precise - and there are a lot of very precise new cats
• Category:Conjugated ketones appears to be grouping vicinal ketones but is full of miss-assigned compounds - Oxalic acid for example
• Adventures in sub-categorisation: Category:Phenol esters is now a sub-cat of Category:Phenol ethers, many other examples exist, for instance splitting Category:Fibrates (14 pages) into those which are and aren't Category:2-Methyl-2-phenoxypropanoic acid derivatives

I could go on and I invite you to review the work done. I'm aware that on an individual basis many of these categories could be argued over - how broad is too broad and how narrow is too narrow, what's in a name etc? I was hoping therefore that some sort of consensus/mandate could be reached before I do anything more.--Project Osprey (talk) 09:32, 30 August 2019 (UTC)

The concerns raised above seem valid at least in the cases I checked. So hopefully that well-intentioned but ill-conceived work will be undone, and The Nth User will desist or at least consult. Another question: Does anyone aside from editors of Wikipedia really pay attention to categories? --Smokefoot (talk) 12:16, 30 August 2019 (UTC)

Part of my rationale for creating specific categories is from Template:Uncategorized. The wording on an article is, "This article has not been added to any categories. Please help out by adding categories to it so that it can be listed with similar articles." I interpreted the last part to mean that the purpose of categories is to display articles that share a similarity (which, for chemical articles, is typically a structural similarity), so structurally similar articles should have a category created for their structural similarity. This was my reasoning behind some of the categories for compounds with a specific substructure, like Category:2-Methyl-2-phenoxypropanoic acid derivatives and Category:3-(5,6,7,8-tetrahydro-(1,3)dioxolo(4,5-g)isoquinolin-5-yl)-3H-2-benzofuran-1-ones. Care to differ or discuss with me? The N^th User 22:48, 31 August 2019 (UTC)

Nomination for deletion of Template:Chem A-Class

Template:Chem A-Class has been nominated for deletion. You are invited to comment on the discussion at the template's entry on the Templates for discussion page. PC78 (talk) 19:29, 7 September 2019 (UTC)

Chloramine vs monochloramine vs chloramines

Chloramine, monochloramine, and chloramines all point to chloramine. Trichloramine and dichloramine and chloramine-T have their own articles. We don't have an article on chloramines as a class although they have a significant literature.

It seems that a viable solution is:

• move most content in chloramine to monochloramine, with a chembox.
• Chloramine would become an overview article on the functional group.
• Chloramines would become a disambiguation article, pointing to mono-, di-, tri- and the organic derivatives.

The main challenge is that many articles that point to chloramine would require modification. Suggestions welcome.--Smokefoot (talk) 20:30, 21 September 2019 (UTC)

I like the idea of cleaning this up, and especially distinguishing the specific NH2Cl chemical from the general ideas. Chloramine (disambiguation) is the MOS-compliant name for a DAB page. Compare that the plural could as easily refer to the class page (when else would one pluralize that word linguistically?) as the set of different singular things that use the word. Do we even need a DAB page? For example, nobody would say "chloramine" when they actually mean "dichloramine". There are less than 200 links to "chloramine", which is not an onerous task. DMacks (talk) 21:52, 21 September 2019 (UTC)

Not quite random articles needing chemists

In the course of searching the term "chloramine", I encountered many unusual articles. These articles, which seem to exist in an orbit not visited by chemists, would benefit from some light checking:

• Chlorine-releasing compounds seems to contain a lot of synthesis. It is not clear what is even meant by "releasing chlorine".
• Corrosive substance. Seems to contain a lot of synthesis. Maybe merge to corrosion.
• Acute inhalation injury. May contain a lot of synthesis. Is there even a definition of the topic?
• Chloramination probably a serious topic with no decent refs
• Swimming pool sanitation may contain hearsay. One of the principal venues that normal people encounter some aggressive chemicals.
• Electrophilic halogenation needs some improved art work. Catalysts are not intrinsic to the def.
• Zerovalent iron needs a chemist. Sure means something different from organometallic def. Jargon, I guess.
• Ecotoxicity, probably needs someone fluent in chemistry. We can agree that chemicals can be dangerous, but some balance might be welcome here.
• Housekeeping Topic is so broad that it is an invitation for some mis- or overstatements.
• Disinfection by-product broad and synthesis.

--Smokefoot (talk) 14:36, 24 September 2019 (UTC)

Paracetamol boiling point

Would someone please check an IP's edit at Paracetamol. It changed the boiling point from 420 to >500 ("based on pubchem"). The greater-than sign causes an error, but is the edit correct? Johnuniq (talk) 09:49, 24 September 2019 (UTC)

@Johnuniq: Now, I agree that the 420 is not carrying a reference either, but 'based on pubchem' means that there is a publication behind that piece of information on pubchem that verifies that '>500'. I presume anyway that you cannot distill paracetamol at ambient pressure (most organics do not survive 420, let alone >500), so the original data is likely a vacuum distillation with a reasonable boiling point and then extrapolated to be at 1 atm.

I have reverted this edit, someone should try to find the reference behind either datapoint (and likely put the boiling point as found in said publication). --Dirk Beetstra ^{T C} 10:11, 24 September 2019 (UTC)

Here Mechanical Studies and Thermal Kinetics of Paracetamol Crystals by S. Ramukutty, E. Ramachandran, meAsured and claimed boiling point is 315.8°C. Using a vapour pressure curve I get around 440°C. This company http://www.thegoodscentscompany.com/data/rw1197931.html claims 387 to 389°C. Graeme Bartlett (talk) 22:51, 24 September 2019 (UTC)

The article here (cited in the first mentioned by GB) is a good ref on the melting points, but does not mention boiling points. It does point to further thermal studies. --Dirk Beetstra ^{T C} 03:45, 25 September 2019 (UTC)

Representation of organometallic complexes

Coming from commons:Commons:Deletion requests/File:Mangafodipir.png, two questions regarding how to draw bonds and charge details of ligand–metal bonding:

1. Should we represent bonds from neutral donors as plain lines (like normal covalent bonds) or as dotted lines (special representation of dative coordination)?
2. Should we represent bonds from anionic donors as plain lines with the atoms uncharged (like normal covalent bonds) or as dotted lines with the atoms charged (special representation of ionic interaction)?

Pinging especially Edgar181, who started that COM:DR, and Smokefoot, who edits lots of organometallic articles. DMacks (talk) 15:15, 22 October 2019 (UTC)

Thank you for starting this discussion.

Prelude: what organometallic/coordination chemists do is not entirely logical. Some organic chemists diverge.

Main rule: In our depictions we usually do not distinguish M-X (X = halide, alkyl, ... some sort of anion) from M-L (L = "neutral Lewis base" such as NH₃, PR₃, CO). To us, the line means that there is a 2-center, 2-electron interaction. When discussing electron counting, however, we will resort to line (anion) vs arrow (Lewis base) convention.

Like organic chemists, organometallic/coordination chemists tend to draw bonding arrow for very classical Lewis acid-base adducts like Me₃N→BH₃. --Smokefoot (talk) 16:46, 22 October 2019 (UTC)

The simple answer from me, unfortunately, is "I don't know". I have created and uploaded images using both of these styles. One uses the typical solid line of a covalent bond as in File:Cis-Dichlorobis(ethylenediamine)cobalt(III) chloride.png, to pick one at random. (As an organic chemist, sometimes this makes me uneasy because of the four bonds to a nitrogen with a neutral charge, but that's just my bias and I recognize that this an accepted, standard method and so I have uploaded files like this anyway). The other uses dotted lines to depict these bonds as in the file that started this discussion, File:Mangafodipir.svg. In my experience, both styles are well-understood to be equivalent and both are generally considered acceptable. I'd be happy to adjust any of my uploads to use a different style if that's what others think would be best. -- Ed (Edgar181) 18:35, 22 October 2019 (UTC)

Recent addition at amphetamine

A recent edit to amphetamine (diff) adds a claim that I tried to verify. I find it a bit surprising that a novel result such as the first identification of amphetamine in a natural source would not be highlighted in the abstract (the only part that I have access to). Can someone with full access to the two references provided in the edit verify that the statement is true? ChemNerd (talk) 17:59, 18 October 2019 (UTC)

The refs do support trace presence (ppm level) of amphetamine in these two species. However, the refs do not appear to support that amphetamine had earlier prior to those reports (or in any earlier time) been solely considered a human invention. DMacks (talk) 17:16, 19 October 2019 (UTC)

Is there any change to the current wording in the article that you would suggest? ChemNerd (talk) 20:03, 21 October 2019 (UTC)

I've been aware of those 2 papers for ~3 years, but I haven't come across either a corroborating primary study w.r.t. amphetamine being a natural product or a secondary source which discusses that finding (and cites either paper). I'm not sure if reproducibility problems are common with studies that use GC-MS to identify plant metabolites (or chemicals in general for that matter); however, given that the same set of authors published both papers and the fact that I haven't seen any other sources assert their findings, I don't think it's a good idea to cite these papers to support the statement that amphetamine is a natural product in those plants.

Chemistry isn't really my forte though, so if others here think there probably isn't an issue with reproducibility in this case, I'd defer to that judgement. Seppi333 (Insert 2¢) 06:27, 23 October 2019 (UTC)

Lead(II) nitrate

I have nominated Lead(II) nitrate for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. DrKay (talk) 11:53, 26 October 2019 (UTC)

The problem with Lead(II) nitrate article is that the compound is so very unimportant. If there is the will to feature something from chemistry, we'd rather feature something cool, significant, or beautiful. Lead nitrate is some grade-school salt that most of us avoid. The other problem is that the article propagates a chemophobia because the compound is not only useless, it is also fairly toxic. If one asked a contemporary, active scholar about something interesting in their field, lead nitrate would not be mentioned. I have nothing against toxic compounds, but there are many where the toxicity leads to beneficial developments in the sense that many highly toxic compounds underpin the development of useful drugs. --Smokefoot (talk) 14:19, 26 October 2019 (UTC)

Allow me to object, Smokefoot. This is an encyclopedia, not a (newspaper, popular TV-show, blog, pub talk). Our task is to describe stuff correctly, sourced, readable. "unimportant"—does not matter. If it is an FA, it is fit for mainpage full stop.

Let us be inspired by The New Yorker attitude: if is is well written, everything can be an article. And so an FA. -DePiep (talk) 19:23, 26 October 2019 (UTC)

Request for information on WP1.0 web tool

Hello and greetings from the maintainers of the WP 1.0 Bot! As you may or may not know, we are currently involved in an overhaul of the bot, in order to make it more modern and maintainable. As part of this process, we will be rewriting the web tool that is part of the project. You might have noticed this tool if you click through the links on the project assessment summary tables.

We'd like to collect information on how the current tool is used by....you! How do you yourself and the other maintainers of your project use the web tool? Which of its features do you need? How frequently do you use these features? And what features is the tool missing that would be useful to you? We have collected all of these questions at this Google form where you can leave your response. Walkerma (talk) 04:24, 27 October 2019 (UTC)

Heavy water

I'm hoping someone will check this edit at Heavy water and fix if needed. Johnuniq (talk) 09:16, 15 November 2019 (UTC)

Trimmed. I see no reference, and even if true, it should not go in the lead. It is probably original research. Graeme Bartlett (talk) 12:35, 15 November 2019 (UTC)

Thanks. Johnuniq (talk) 23:26, 15 November 2019 (UTC)

Improve identification

WD has some problems to identify the main topic of WP articles, especially for stereoisomers. Often infobox mixes data about both isomers and even about the mixtures of isomers. Ex: Acetylleucine. Could you define some kind of policy to clearly show which is the chemical described by infobox data ? I don't ask a complete removal of data about other stereoisomers but to have a way to identify which data are together. My opinion is that each chemical or mixture deserves a dedicated infobox, and I would prefer to have 2 or 3 infoboxes than one mixing data. Snipre (talk) 14:14, 11 November 2019 (UTC)

The mechanism available in {{Chembox}} (and, in a lesser degree, in {{Infobox drug}}) is called Indexes. I will decribe it here. (While I think you already might know & understand its system, this question looks like its systematic usefullness is out of sight. IOW, I write this at the risk of being pedantic towards you).

For identifiers, indexed IDs are available, like: | CASNo = | CASNo1 = | CASNo2 = | CASNo3 = | CASNo4 = | CASNo5 = , allowing for six distinct compounds. Whether the distinction is re isomers or otherwise, is free to choose. Some 1700 articles use these: Category:Chemical articles with multiple compound IDs (2,199), including Acetylleucine.

Essential is that a specific index is resused for a single, same substance:

CASNo3 ≡ ChEBI3 ≡ ChemSpiderID3 ≡ PubChem3 ≡ SMILES3 etc.

It is up to the editor to maitain this integrity. It is also possible to specify the indexes:

By using like |CASNo2_Comment =<small>''S''</small> (see Acetylleucine)

By listing the indexes and specs in top: see Linalool.

Drawbacks:

It requires editor's attention to maintain data integrity

Indexes only work within the section {{Chembocx Identifiers}}, not in say section Properties (so melting point can not be indexed this way for multiple individual compounds).

{{Infobox drug}} only has two indexes.

The policy Snipre is asking for at least should be the existing guideline: use indexes, and use them consistently.

So while there is this systematic option, do you Snipre experience that the info is sloppy or missing, eg re stereoisomers? I myself cannot check for this. -DePiep (talk) 17:16, 11 November 2019 (UTC)

I think it would be a very bad idea for Wikipedia to change the way it writes its articles or presents data in order to suit the needs or preferences of Wikidata. In most cases, it is much better to discuss stereoisomers at the same article and have the data presented within a single infobox than to have multiple articles or multiple infoboxes. Wikipedia articles are for its readers and they, not Wikidata, need to be our focus. I think acetylleucine is a great example of doing it the right way. ChemNerd (talk) 17:27, 11 November 2019 (UTC)

@DePiep and ChemNerd: As WD contributor, I don't spend a lot of time to look at the wikicode to understand the data structure and I assume most reader will do the same. So even if you build a very good structure in wikicode, this is not clear for reader point of view.

Just a fast criticism of the mentioned example:

The name of the article, the title of the infobox and the IUPAC name don't indicate anything about the stereoisomer. We can guess that the article is about the natural isomer or the one which have some health effect, but nothing to garantee that.

Other name provides the msot important parameter: we are speaking about L isomer.

But looking at the other identifiers in order to find the relevant ones for L isomer, I only find R or S information. Please let me know which is corresponding to L isomer. I can only guess from that page based on statistical assessment (there are more data about S form than for R form) that L form is corresponding to S form.

If I continue, and trying to keep some logical approach, I remembered that the infobox is about L form: so I should expect that all first identifiers are about L form. No, for CAS, ChemSpider and PubChem, the first value among the 3 mentioned is about the mixture. This is not critical because I have the information beside the value. But now I study the identifiers with no stereoisomers information: EC number, 3DMet ChEBI, KEGG, MeSH and UNII. Are they representing the L form or the mixture ? I could not logically assume that they are about the L form because 1) identifiers about one stereoisomer form are always marked (see CAS, ChemSpider and PubChem in case of multiple values and Beilstein and Gmelin in case of unique value), 2) no stereoisomer information means identifier for mixture (see CAS, ChemSpider and PubChem).

And what's about ChEMBL ? Two values and no information about the stereoisomer forms.

I don't ask you to modify your data presentation because WD requests it, I ask you to improve your infobox structure because as WD contributor, I tried to connect your article to the correct WD item (WD policy about chemical is to generate one item for each stereoisomer form, another one for the mixture and even an additional one for the racemate) and as WP reader I don't want to spend more than 1 minute to identify what is the topic of the article (I am doing the same job with other WPs so thank you for your understanding when I ask you to help me to save my time).

@DePiep. Instead of a long explanation requiring to have a look at the wikicode, a simple policy could be: if identifiers about several stereoisomer forms are presented in the infobox, all stereoisomers form has to be identified using DL or RS tag, values without DL or RS tag representing the mixture form. Following that policy I can define that EC number, 3DMet ChEBI, KEGG, MeSH, ChEMBL and UNII were not correctly added in the infobox and I can try to identify the topic of the article without taking account of them.

I finish with that conclusion: as reader of the article, without a deep knowledge of the topic, if I want to find the correct value I need, I have to guess and check your data because your presentation in the infobox is not structured in a systematic way.

I know the infobox was not built in one day and there are several stages in the development, and I was expecting to get some answers like "we know the problem, we working on it". But looking at the last answer, I just have the impression that you are clompletely closed to any new idea and that the reader point of view is completely out of scope for WP:en contributors. So I will pass my way and stop my work on curating sitelinks on the benefit of WP:en articles. Snipre (talk) 21:02, 11 November 2019 (UTC)

Instead of a long explanation ... -- Are you blaming me for trying to explain something, something I assumed you knew but did not invoke in your OP? Anyway, if I understand you reply wrt this point, I think a short explanation would not have helped either.

Your OP started with "WD has some problems to identify ...". I Therefrom I assumed that the reading was automated, and so parameters were read. In your 2nd post though you approach the article/infobox as a reader, "requiring to have a look at the wikicode". 1. That's a change of approach then, from WD (automated) to you (human) reading. 2. And no, a human reader is not required to look at the code either. As explained and examplified, the structure is visible & readible to the human eye too.

I'll leave here for now. -DePiep (talk) 21:20, 11 November 2019 (UTC)

@DePiep: I was not blaming you, but the reply of ChemNerd was so unfriendly just because of the mention of WD that my reply was certainly too direct.

Again my request is a policy demand not a technical description because most of people reading the article never have a look at the wikicode. And if you read again my first comment, "WD has some problems to identify the main topic of WP articles": even if the IDs are well defined in the infobox with a S/R or D/L index, how this can help to define the main topic of the article when data are mixed in the infobox ? I was mainly focusing about infoboxes because with the display of identifiers, this should be the main place to find a clear definition of the chemical described by the article (most of the time, the article is not using the correct name or the full nomenclature to name the molecule).

So please, show me in the example I mentioned where I can find the full description of the chemical described by the article: where can I find in a systematic way if the article is speaking about the L form, the D form or about the mixture of both forms.

And if I mentioned WD, this is not because WD wants to change WP:en, but because people working on chemicals in WD struggle to curate items with data imported from WP:en. We just want to understand how we should use data from infoboxes, not for data import, but only to identify article topic. Snipre (talk) 21:44, 17 November 2019 (UTC)

The chembox also has qid1= qid2= etc which I though were supposed to identify the wikidata entry for the multiple labels. They don't seem to do anything such as retrieving the wikidata entries for display, but perhaps they should, and we could put in some effort to add this mapping. I also use index_label for different degrees of hydration, or different chemical formulae for the same name. For some natural products they have variations labelled A, B, C etc that I would also add an index label. It is not just stereoisomers. Graeme Bartlett (talk) 00:37, 12 November 2019 (UTC)

You are right wrt |qid1= etc. Since they are not used to show any feedback, their input is not tested, and so they are less reliable (one design idea was to use them in preview only). IIRC there was opposition here to have these parameters at all (Wikipedia:Wikidata/2018 Infobox RfC). -DePiep (talk) 07:27, 12 November 2019 (UTC)

In general, if it's based on an amino acid then it's in the L-form. I've expanded the index tags a bit to try and clarify things. I'd try to stay clear of L- and D- because they're likely to be confused with l- and d-, which are different, the natural human tendency to start sentences with a capital letter probably means that there are a great many errors in the chembox data regarding this. EC number, 3DMet ChEBI, KEGG, MeSH, ChEMBL and UNII are not important databased for most chemists, I've never accessed any of them. CAS No is the de facto top-level identifier in all articles. I am sympathetic to your concerts regarding pages containing multiple isomers but it's actually worse than you think. Once your get into diastereoisomers all the physical data starts changing too. In the years before DePiep developed the Index System these issues were often dealt with in an ad hoc way which was different on every page; see Tartaric acid or Periodic acid. This is all perfectly human readable but unless WikiData uses ontological reading then it probably struggles. --Project Osprey (talk) 11:27, 12 November 2019 (UTC)

@Project Osprey: Tartaric acid is clear because for all identifiers, there is only one value. I just need to click on several links to identify the mixture of isomers. Now please have a look at Acetylleucine: how can I define if the article is describing the mixture of isomers or the L-form based on the identifiers of the infobox ? Snipre (talk) 21:56, 17 November 2019 (UTC)

I'm not sure I follow, all of the unique identifiers are indexed (?) --Project Osprey (talk) 22:04, 17 November 2019 (UTC)

Sulfacetate

When checking if sulfacetate is a real word, I came across the Aluminium sulfacetate page which claims that this compound exists. But from the reference it just looks like a mixture of aluminium sulfate and aluminium acetate dissolved in water. Is this a real (solid) chemical? It last seems to be talked about in the 19th century. Is there such a thing as a double sulfate/acetate compound anywhere anyway? Graeme Bartlett (talk) 12:38, 16 November 2019 (UTC)

Looks archaic. Almost nothing in Chemical Abstracts. No mention Ullmanns. No Xray structure in the Cambridge database with Al-acetate-sulfate. In dye chemistry, especially the older literature, all sort of "medieval" crud was once added and dignified with fancy names. It is surprising that so much detail is provided on a material that is probably not real. --Smokefoot (talk) 13:07, 16 November 2019 (UTC)

Thank you Smokefoot. I have edited this so that is it not a "compound", and also removed it as the prime example of a double salt. Graeme Bartlett (talk) 06:19, 17 November 2019 (UTC)

I dunno about sulfacetate but sulfoacetate is a real thing, is has the worlds easiest CAS no 123-43-3. --Project Osprey (talk) 22:00, 17 November 2019 (UTC)

Good catch. That RN refers to HO2CCH2SO3H, an oxidized derivative of mercaptoacetic acid. CAS has about 500 citations, usually fairly tangential. But aluminium sulfacetate appears to be obscure.--Smokefoot (talk) 13:59, 18 November 2019 (UTC)

Nicotine salt

Article needs an image and an info box. The structure of a nicotine salt with an acid such as benzoic acid is different. QuackGuru (talk) 20:24, 18 November 2019 (UTC)

I have added a chembox, but there are a lot of salts, so perhaps a chembox is not the best way to go. A table may be a better way to represent a large number. I can also see a bitartrate, and a salycilate, hydrotartrate, citrate, di-p-toluoyltartrate, perchlorate, hydroiodide. Some would be easily volatilized, others could be unpleasant to smoke. Graeme Bartlett (talk) 22:45, 18 November 2019 (UTC)

Other forms of nicotine salt can be added to the article. I only added the ones associated with vaping. I would add an image of nicotine benzoate to the chembox. A table can be added to a separate section in the article. I'm not sure if there is room for a table at the top of the article. QuackGuru (talk) 23:32, 18 November 2019 (UTC)

A table could go in its own section lower down. After looking at a patent, some of these may just be some kind of mixture, but I did not investigate how they work. Not everything in the article has a pubchem number. Graeme Bartlett (talk) 01:33, 19 November 2019 (UTC)

There is very little research on the topic. Most of the vaping research on nicotine salts is related to Juul. I would add the table at the end like a gallery section. QuackGuru (talk) 02:15, 19 November 2019 (UTC)

New paper on stable nitrogen-six at 1 atmosphere and as high as -50 C

I'm referring to this:

https://iopscience.iop.org/article/10.1088/1361-6463/ab349a

It may impact these Wiki pages:

https://en.wikipedia.org/wiki/Hexazine https://en.wikipedia.org/wiki/Heterocyclic_compound

Just FYI to whomever manages/edits these pages.

(I'm a complete neophyte about contributions and/or editing of Wiki pages and don't want to make a mess of things due to my ignorance and I don't have the time to invest in becoming more savvy, right now.)

It appears that something green was made, but it is not well characterized at all as to what it really is. No structure is suggested yet, whether it is a ring or linear or some other shape. Only a comparison is made with some theoretical molecules. So it would be premature and original research to go in heterocyclic compound. (I would suggest that the researchers use pure liquid nitrogen or liquid helium, and platinum electrodes and higher resistance cables to reduce all the side products. But that is outside the scope here.) Since this was funded by an army, probably the product is not useful for explosive or missile fuel! Perhaps it can get a mention in the azide page, because there is not yet enough for a stand alone article. Graeme Bartlett (talk) 22:01, 25 November 2019 (UTC)