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Magnesium hydride

Would someone please check an IP's recent edits at this article. The error in MeltingPtC is due to "566 C" (the "C" should be removed, but what about the value?). Johnuniq (talk) 06:24, 5 February 2018 (UTC)

CRC handbook has 327 C, not as decomposing, chemspider has 327 decomposing and 648 C..going with CRC value for now. Galobtter (pingó mió) 06:33, 5 February 2018 (UTC)

Chembox for "world's most boring isomers"

Although the isomeric monoesters of glycerol seem pretty boring for most of us, they are also numerous, and some are important. They are somewhat complex as illustrated by the monostearates. Then there are homo and hetero diesters. ...

cmpd reg number number of hits comment
glycerol stearate 31566-31-1 17600 hits mixtures of 1-stearoylglycerol (racemate, I guess) and 2-stearoylglycerol
(+)-1-stearate 22610-61-3 41 hits one enantiomer
(-)-1-stearate 14811-92-8 36 hits the other enantiomer
1-ester, racemate 123-94-4 900 hits currently shown for glycerol monostearate, but I am considering switching to 31566-31-1
2-ester 621-61-4 180 either less stable than 1-ester or authors don't distinguish

Approaches:

  • separate articles with individualized Chemboxes for each isomer (seems ridiculous)
  • single article and single ChemBox with multiple entries recognizing the isomers and forms. Can or should the box handle multiple entries for each category?
  • single article and single ChemBox for the dominant form (mixture of isomers usually).
  • a disambiguation page that indicates each of the forms with side-by-side boxes, then a master text-y page that focuses on the main form.

‎

If we can figure it out, a good solution would apply to many compounds. --Smokefoot (talk) 13:25, 4 January 2018 (UTC)

I am tempted to suggest one article for the 2-ester, and 1 article for rac-, +-, and —isomers for at least the (biologically) most important one(s) (likely the stearate, maybe the acetate; q: do enzymes distinguis + and -?). Rest can probably be ignored and only one compound be having an article, with a paragraph to describe the then way less important isomers. They would only get an article when really (biological) significant. (The paragraph should probably point back to the situation with the stearate). —Dirk Beetstra T C 13:37, 4 January 2018 (UTC)
I think it can all be handled in one article with one chembox. Since it is clear from the number of hits for each isomer that glycerol stearate is the only major topic, I think your option "single article and single ChemBox for the dominant form" would work best. I don't see any justification for a separate article for the 2-ester. -- Ed (Edgar181) 13:55, 4 January 2018 (UTC)
From {{Chembox}} point of view: one can use #Indexed_parameters for most identifiers (example articles) and multiple #images to one box. Ping me if that is not fitting. Also I saw a nice custom-made wikitable with columns for four compounds, very useful to compare properties etc. by presentation. -DePiep (talk) 14:28, 4 January 2018 (UTC)
  • I'm broadly in favor of option 3 as that's normally what you get when you buy these things and so that's what most of the literature is describing. There are a few monoglycerides with biological activity (2-Oleoylglycerol, 2-Arachidonoylglycerol) but I think we can leave those to the bio/phara people. The situation with the di-esters is more complex because effort has been made to improve selectivity towards 1,3-diesters (purported health benefits: apparently it reduces weight gain) so there are a lot of grades. Where are you putting all this? --Project Osprey (talk) 16:07, 4 January 2018 (UTC)
Ok, I will switch out the registry number currently shown for glycerol monostearate to the registry number for a mixture of three isomers, and add an image of the 2-isomer. One concern is that the physical data and identifiers are for an individual isomer (1- isomer). Any advice on that aspect?--Smokefoot (talk) 18:53, 4 January 2018 (UTC)
Any chance physical data for the triple-mixture will show up? -DePiep (talk) 19:40, 4 January 2018 (UTC)
See User:DePiep/sandbox for a crude muckup (parameter test). Note index- and CASNo usage (sort of completed). Cannot solve easily: multiple, noted data sections (physical props). However, we already can add multiple "Physical data" sections (just not title them different). Will demo in sandbox. -DePiep (talk) 20:03, 4 January 2018 (UTC)
Am inserting m.p. and density per SciFinder's numbers. I doubt if anyone distills this material. --Smokefoot (talk) 20:22, 4 January 2018 (UTC)
  • Actually, on consideration, I think we may as well include the 3 main forms using indexed parameters. I've made the changes but please note that the indexing system doesn't extend to things like melting point, so I've sorted that out myself (... so if you want to change the index labels you will also need to change the melting point labels so that they all match). If you don't like it do feel free to revert. --Project Osprey (talk) 09:45, 5 January 2018 (UTC)
  • (ec) New approach. Maybe squeezing all this in a {{Chembox}} (infobox!) is not best way to start. What if the article has this:
A section with few columns: structural image, name (stereometric prefixes!), CAS number, note. This would make excellent comparing & showing the difference.
Then for each compound a dedicated section, possibly with a data section {{Chembox}} (properties, hazards listing). No images in the box, not identifiers.
A racemic can be together in one section. Having two {{Chembox}}s side by side showing data.
Once this setup is stable and filled, the infobox content can be deducted from these. This top (common) {{Chembox}} can have the indexed identifiers.
I mention this because even an ideal {{Chembox}} cannot produce the overview and detail and variants that is desired here. Also, if I understand this well, the relationship between the various compounds is not straightforward family like (triple mixture, racemic, complete isomeric pair, important variants, ...). Just think of what an editor can do with structure-by-articlesection! -DePiep (talk) 20:33, 4 January 2018 (UTC)

About hydrated metal salts

The above issue with many variants and the Chembox may also apply to most transition metal salts (nitrates, sulfates, chlorides, bromides) because almost all exist in anhydrous and various hydrates, as summarized in the table water of crystallization#Table of crystallization water in some inorganic halides. Anhydrous vs each of the various hydrates are different materials in terms of physical properties and structures. Some hydrates, anhydrous etc can be interconverted, some cannot. Night and day sort of thing often. My cursory checks indicate that many ChemBoxes present data for anhydrous, but acknowledge the various registry numbers, but do not attempt to present data for each hydrate.--Smokefoot (talk) 20:50, 4 January 2018 (UTC)

WTF is this??? Graeme Bartlett replied to my post, and now someone turned it into some new thread? -DePiep (talk)
Some hydrates are notable and deserve a separate article. Perhaps up to three infoboxes are OK for one article, but with more it takes up too much space on the right side, and would overdominate the mobile view. Some properties like hazards are very likely to be the same for all these isomers. And some other properties would be irrelevant for different isomers, even though they might be measureable, eg optical dispersion, variation of density with temperature. (But for mineral forming chemicals, these may be important, so we have separate articles for minerals that just differ in hydration). A table is a better way to present information for a lot of chemical variants. In the case of gycerol stearate, the 1-ester and 2-ester are really different compounds deserving articles. Graeme Bartlett (talk) 04:19, 5 January 2018 (UTC)
An example edited today is vanadyl sulfate, a common source of vanadium in the lab. The chembox:
  • photo = hydrate of some sort
  • structure picture = pentahydrate.
  • CAS = anhydrous
  • Chemspider (ever useful for inorganics?) = anhydrous
  • Pubchem = anhydrous
  • formula = anhydrous
  • appearance = probably hydrate, unspecified
  • melting point = apparently a hydrate
  • solubility = apparently hydrate
  • etc

So here we have an article where the chembox basically presents either useless (no one uses the anhydrous material) or confusing (hydrate no specified) information. So one approach would be to resolve that the chemboxes contain data uniformly for the most common hydrate (or in some cases anhydrous) form. And that the CAS registry numbers be noted. The text would just need to be careful to refer to various forms being careful to note which is being discussed. I dont think that readers want to read four articles on vanadyl sulfate, although some have articles on the minerology. But the mineralogy articles are not very chemical, and most or many hydrated salts are minor secondary minerals. --Smokefoot (talk) 13:08, 5 January 2018 (UTC)

Is there an anhydrous form of vanadyl sulfate? like V(O)SO4?... In any event if both sets of data are available we can just list both. --Project Osprey (talk) 13:31, 5 January 2018 (UTC)
It appears that four forms of vanadyl sulfate have been crystallized, including two polymorphs of the anhydrous material (which probably no one is interested in except a handful of crystallographers). Unformated output from Karlsruhe Xray database.
  • α-anhydrous (V O) (S O4) VOSO4-alpha Structure and magnetic properties of V O S O4 Longo, J.M.; Arnott, R.J. Journal of Solid State Chemistry (1970) 1, (*) p394-p398.
  • β-anhydrous (V O) (S O4) VOSO4-beta Synthesis, crystal structure redetermination and vibrational spectra of beta- V O S O4 Boghosian, S.; Eriksen, K.M.; Fehrmann, R.; Nielsen, K. Acta Chemica Scandinavica (43,1989-) (1995) 49, (*) p703-p708.
  • trihydrate VOSO4(H2O)3 Liaisons hydrogene dans les cristaux de sulfate de vanadyle trihydrate V O S O4 (H2 O)3: Comparaison structurale de quatre sulfates de vanadyle hydrate Tachez, M.; Theobald, F.R. Acta Crystallographica B (24,1968-38,1982) (1980) 36, (*) p2873-p2880.
  • pentahydrate (V O) (S O4) (H2 O)5 Structure du sulfate de vanadyle pentahydrate V O (H2 O)5 S O4 beta (variete orthorhombique) Tachez, M.; Theobald, F.R. Acta Crystallographica B (24,1968-38,1982) (1980) 36, (*) p1757-p1761

--Smokefoot (talk) 14:15, 5 January 2018 (UTC)

The problem is coming from the usual habit of simplification: people don't take care about accuracy and this leads to confusion. A good solution is to use a disambiguation page with a table having one column for each isomer/hydrate and a section presenting the different isomers/hydates including the link to the specific articles if they exists. So if article about vanadyl sulfate is not representing the anhydrous form (if not, how should we define the anhydrous form ?) but all possible hydrates, then a page having a table similar to one available in de:Dichlorbenzole presenting all possible hydrates with relevant data should be created and the current page vanadyl sulfate should be renamed vanadyl sulfate pentahydrate. This is really important for identifiers because too many people mix information mainly because they don't take care to be accurate. This problem is common with external databases and WP could be a more reliable source of information if we have more strict rules like "one chembox = one compound" and if we want to show data about different compounds in one article, we should be really clear be presenting in a separate way the data. I don't count the number of articles about one active substance which present data about the chloride salt in the chembox. The name of the article has to be the more accurate as possible or has to present all possible forms which can be defined with the article's title. Snipre (talk) 21:36, 5 January 2018 (UTC)

Maybe that is the solution to the simple aquo salts. Many or most molecular compounds crystallize as solvates, i.e. with H2O, EtOH, MeCN, benzene. And then most coordination complexes (among other things) crystallize with diverse counteranions and countercations. For example, ferrocenium tetrafluoroborate is popular but so is the PF6- salt. Readers may only be interested in the ferrocenium part of the salt, or seeking data on the entire salt. --Smokefoot (talk) 01:31, 6 January 2018 (UTC)
I think that the indexed entries would be solution to adding the different variants. Those other kinds of solvated crystalline products would not normally be important enough to rate a mention in the info box. However if it was the form sold or commonly used, then yes add it in with an index. Some substances may have excessive known unimportant hydrates though, eg Magnesium sulfate or Sodium magnesium sulfate. Graeme Bartlett (talk) 07:10, 9 February 2018 (UTC)

Methyl butyrate & 3-Methylbutanoic acid

Should Methyl butyrate be disambiguated from 3-Methylbutanoic acid? Specifically, I'm asking if the following should be done:

  1. Create Methylbutyrate and/or Methylbutyric acid as a {{Chemistry index}} of the corresponding acids/bases of 3-methylbutanoic acid and methyl butyrate (which is about N-methylbutyrate)
  2. Move methyl butyrate to N-Methylbutyrate, then redirect methyl butyrate to methylbutyrate


Unrelated question: is there a Wikipedia article on isoamylamine located under a different pagename (i.e., not isoamylamine)? I can't seem to find an existing article on this compound. Seppi333 (Insert 2¢) 13:37, 22 February 2018 (UTC)

Regarding your second question: apparently not --Project Osprey (talk) 13:50, 22 February 2018 (UTC)
Methyl butyrate should definitely not be moved to N-Methylbutyrate, which is not a valid chemical name for the compound ("N-" means attached to nitrogen, but that's probably not what you intend to mean. A plausible synonym could be methyl n-butyrate, where "n-" is means normal, or straight-chain, but that would be an uncommon synonym at best). I think this can be handled with hatnotes and with chemistry index pages without having to move or rename anything. I have created {{Chemistry index}} pages for methylbutyrate and methylbutyric acid. -- Ed (Edgar181) 14:08, 22 February 2018 (UTC)
@Edgar181: Thanks for doing that! My bad about the proposed page move. As you know, I'm a bit derp when it comes to chemical nomenclature. Seppi333 (Insert 2¢) 16:03, 22 February 2018 (UTC)

Most cited chemical compounds - a worklist

Others must have discussed this topic previously, maybe even me: Do we have a list of those chemical compounds that are most cited in Chemical Abstracts? This list could guide activities, perhaps even school assignments. The list would ideally be very long, but for starters, maybe the top 2000 - is that the right number?--Smokefoot (talk) 21:02, 15 February 2018 (UTC)

I would love to see such a list. http://www.commonchemistry.org/ is a publicly available database of the most common chemicals appearing in Chemical Abstracts, but I don't know of any way of getting a list from it. User:MichaK/Missing chemicals is an old list generated in 2009 of the most frequently occurring chemicals in PubChem that did not have Wikipedia articles at the time. Maybe you would find that helpful. -- Ed (Edgar181) 21:09, 15 February 2018 (UTC)
I imagine things like methanol and water would dominate. There are lists of what chemicals our readers are most interested in (drugs). In terms of ideas for work-lists: Unilever and P&G have stated listing all their indigents online, considering that most of us are directly exposed to these compounds on a daily basis it might surprise you how many are missing from here. --Project Osprey (talk) 16:04, 16 February 2018 (UTC)
OK, but still: when we Venn-cross these substances, a new set might appear. Any list-and-crosscheck ideas? - DePiep (talk) 21:58, 16 February 2018 (UTC)
I am also starting to make a list in User:Graeme Bartlett/missing chemicals from an old chemical dictionary I have. But its appearance in there does not mean it is heavily cited. There's also User:Skysmith/Missing topics about Chemical compounds, and Wikipedia:Requested articles/Natural sciences/Chemistry and Wikipedia:WikiProject Chemistry/Requested articles. Graeme Bartlett (talk) 06:05, 22 February 2018 (UTC)
Wikipedia:Most-wanted articles has Benzoate degradation via hydroxylation and Glycine, serine and threonine metabolism - a bit outside our scope. Graeme Bartlett (talk) 06:12, 22 February 2018 (UTC)

Alternative options include using toollabs:missingtopics or based on Wikidata (query: chemical compound with at least 2 sitelinks to other Wikipedias). --Leyo 14:08, 22 February 2018 (UTC)

I ran it, but it was dominated by experimental drugs, so I have trimmed it back, also removing people and organisations to make this list: User:Graeme Bartlett/wanted chemicals. Now it is still dominated by minerals. Graeme Bartlett (talk) 05:53, 23 February 2018 (UTC)

3DMet

Useful links: Template:Chembox/doc/3DMet usage (2018) (list)

In the chembox we have a parameter for 3DMet, but for every substance I have found in there, the description does not match the structure, eg http://www.3dmet.dna.affrc.go.jp/cgi/show_data.php?acc=B01584 . Here I wanted the thing in the picture, but the text does not match. Is this database permanently useless and so a waste of time for anyone to lookup? Or is there something good in there? Graeme Bartlett (talk) 09:26, 8 February 2018 (UTC)

Some 120 articles use it [1]. -DePiep (talk) 12:23, 8 February 2018 (UTC)
I've spot checked a number of those. There are indeed quite a few errors (or, to be generous, non-standard representations of charges/protonation states). Graeme's example is indeed, just plain wrong. I don't see much value to the data at the linked pages anyway because much of it is redundant to what is in a standard chembox. And if we can't be confident in the accuracy of the data and how well it is curated, I don't think we should be linking to it. -- Ed (Edgar181) 12:48, 8 February 2018 (UTC)
OK, from the category I have found these errors, the x marks completely wrong, otherwise something is right in 3DMet, but structure does not match the parameters.

otherwise they are correct. So there is about a 20% error rate. Graeme Bartlett (talk) 06:47, 9 February 2018 (UTC)

What I propose is to unlink from the Wikipedia articles after people have had a look to see how bad the situation is! Graeme Bartlett (talk) 08:41, 9 February 2018 (UTC)
Counted: 26 compounds listed out of today's 110 articles (24%) (Chembox articles having |3Dmet= input). - DePiep (talk) 10:42, 9 February 2018 (UTC)
I understand this is about the core function of the 3DMet site (add information to the article). But 24% off - that's not a RS any more. Is there any way that this site can be used usefully & trustworthy? We could also use it's essential (3D?) information to add to say a {{Chembox Structure}} section, and then link to the site as ref (source), not as external link. Note that I am a layman in this chemistry; I'm just about the infobox. -DePiep (talk) 10:49, 9 February 2018 (UTC)
I have created an overview page (see top of this thread). Please ask if it can be made more useful. (Notes: 1. apparently the first example by GB (B01584) has no wiki article now; 2. I have moved the input from ethanol (data page) to ethanol for future treatment). - DePiep (talk) 13:18, 9 February 2018 (UTC)
The original example was for Smokefoot's new page Cyanoalanine. I did not add the 3DMet entry because it did not appear correct. I already removed the entry from Pentadecane as well. Graeme Bartlett (talk) 21:08, 9 February 2018 (UTC)
we need a general conclusion about the site. When good, what info does 3DMet actually add? Then: if anything, is it worth its 24% of sub-correct facts? IOW, is it a RS? We can't leave it to individual articles to say "yeah use here, but no, not here". - DePiep (talk) 21:39, 9 February 2018 (UTC)
I am making contact with 3DMet to see if they will fix things up. If the response is positive, then we can continue to use it. Originally I thought we should link it if the entry looks correct. Graeme Bartlett (talk) 02:04, 10 February 2018 (UTC)
There is no response so far, so I suspect there is no staff for support. Graeme Bartlett (talk) 23:59, 20 February 2018 (UTC)
What does "staff for support" mean? Anyway, I suggest we now conclude: "Not a WP:RS, do no use in {{Chembox}}". What else? (simply said: if you, Graeme Bartlett, check a compound article: how can 3DMet be trustworthy?). I propose to remove the 3DMet data point from {{Chembox}} (do not show, and remove at some time from article page code). If there is an individual page that has reason to use it: then do as a regular source. -DePiep (talk) 00:35, 21 February 2018 (UTC)
Actually , I meant "no staff", prehpas they are all on holiday for new year though. I think it is fair enough for it to be rendered invisible. I have added a couple of apparently valid 3dmet entries in the last week. Graeme Bartlett (talk) 05:56, 22 February 2018 (UTC)
I get it: no reply then. We'll have to draw our own conclusions. -DePiep (talk) 21:41, 22 February 2018 (UTC)
  • I propose (to conclude):
- {{Chembox}}: 3DMet site is not generally an RS. So {{Chembox}} will not show it (& parameter deprecation).
- Article body text: When useful and good info on the site, an editor can link (by <ref>) to the site allright. That is: when individually sourced in an article that is OK.
-DePiep (talk)
Change proposals so far: invalidated after response by the 3DMet maintainer (see below). -DePiep (talk) 09:12, 8 March 2018 (UTC)
I now have a response from the maintainer. They say they will fix up the problem entries, and add more. The id numbers will remain the same. However it will take several months. Graeme Bartlett (talk) 22:10, 3 March 2018 (UTC)
Graeme Bartlett Good. I won't change the template (|3DMet=... keeps showing as it did), unless others here agree to change something. Will revisit after those months. -DePiep (talk) 09:10, 8 March 2018 (UTC)
I have also removed the completely wrong entries that were marked "x". Graeme Bartlett (talk) 10:48, 8 March 2018 (UTC)

Notability of Cyclopentadienyl radical

Cyclopentadiene and various cyclopentadienyl anions (or at least some specific and general classes of salts and cyclopentadienyl complexes) and are quite notable, but is the neutral radical? According to the article history, several editors have expressed concern that it is not, and lots of the content that was written there (and subsequently removed) was WP:OR or actually about other than the radical form. DMacks (talk) 07:43, 6 March 2018 (UTC)

I support erasure and a redirect it to the anion. The article is inadvertently deceptive in that it suggests some significance or prevalence where none has been demonstrated.--Smokefoot (talk) 08:23, 6 March 2018 (UTC)
Actually many articles exist on the Cyclopentadienyl radical, so it is notable. But what we have now is unreferenced and useless, so it may as well be a redirect until someone actually writes about the true radical based on others writings. Graeme Bartlett (talk) 10:45, 6 March 2018 (UTC)
Indeed, Graeme is correct, it is the subject of 500 SciFinder hits, but I still think that the article should be wiped until something useful can be written. I worry about confusion with radical meaning a substituent (ligand) as well as an odd-electron species. --Smokefoot (talk) 13:52, 6 March 2018 (UTC)
I support that editorial option as well. DMacks (talk) 18:22, 7 March 2018 (UTC)
Actually the anion article is itself a redirect to Sodium cyclopentadienide, where it would be even less useful to target the radical redirect. You have to go back to the pre-redirect version[2] to have any content. So the target should be Cyclopentadienyl complex. Graeme Bartlett (talk) 03:56, 8 March 2018 (UTC)
Whoops, good catch about cyclopentadienyl anion being a redirect. There had been an article there until a few months ago when User:Smokefoot redirected it. Maybe let's go back to having an article there? DMacks (talk) 07:21, 8 March 2018 (UTC)
It was also almost useless and unreferenced though. Graeme Bartlett (talk) 10:53, 8 March 2018 (UTC)

List of molecules by year of discovery

Does anyone here think List of molecules by year of discovery is a good idea? I think there are far too many molecules to include on a Wikipedia list like this. Only the earliest discoveries make sense to include. However what's there now is a mess. We already have List of inorganic compounds, List of biomolecules and List of minerals which are big already. Graeme Bartlett (talk) 05:14, 14 March 2018 (UTC)

I'm amused that dinitrogen trioxide was apparently the first molecule ever discovered. Who knew aye? --Project Osprey (talk) 09:28, 14 March 2018 (UTC)
Being serious, I think it should be deleted. I don't know the proper WP: but I'm sure this sort of 'list of everything' must fall foul of something.--Project Osprey (talk) 11:25, 14 March 2018 (UTC)
I agree that it's a bad idea. I also think it mixes two ideas – the discovery of the composition and structure of molecules that already existed and the first preparation of new substances, and only the former are 'discovered' in the literal sense. EdChem (talk) 12:24, 14 March 2018 (UTC)
I have proposed it for deletion. (It is in the same sort of league as list of notable women - ie no limit to its inclusivity) Graeme Bartlett (talk) 12:34, 14 March 2018 (UTC)
It does seem to be a hopelessly unmanageable page. I have endorsed your proposed deletion. -- Ed (Edgar181) 14:19, 14 March 2018 (UTC)
It could be interesting to turn this list say 90°: describe how new techniques or theories have made possible new discoveries. Discovery of the noble gases (ca. 1890), DNA and X-rays, spectrography, ... - DePiep (talk) 11:36, 15 March 2018 (UTC)
The original article has been turned into a redirect and there are now three separate articles instead. -- Ed (Edgar181) 19:50, 15 March 2018 (UTC)
List of molecules discovered in the 19th century
List of molecules discovered in the 20th century
List of molecules discovered in the 21st century

These lists have been nominated for deletion. Please feel free to contribute to the discussion at Wikipedia:Articles for deletion/List of molecules discovered in the 21st century. -- Ed (Edgar181) 12:40, 5 April 2018 (UTC)

On a related note, a series of new categories such as Category:Substances discovered in 20th century and its subcategories have recently been created. Are these useful categorizations? -- Ed (Edgar181) 14:57, 14 March 2018 (UTC)

I was wondering the same thing. Leiem, as the creator of these categories, why do you think that they are useful? EdChem (talk) 19:26, 14 March 2018 (UTC)
It is not useful, as categories should be something that defines the topic. Instead the facts about discovery should be included in the writing of the article text. Graeme Bartlett (talk) 21:58, 14 March 2018 (UTC)
I think, though there are numerous chemicals, only those already existed in English Wikipedia can be categorized. Just like Category:Triclinic minerals (no article named list of triclinic minerals) or Category:Sodium compounds (also far too many molecules). --Leiem (talk) 04:36, 15 March 2018 (UTC)
Both of those are good categories, as minerals are often classified into crystal form. Or compounds can be classified by a significant element. If you think there are two many sodium compounds perhaps try to find a way to subdivide, eg sodium oxides, sodium halides, sodium oxosalts, sodium organic salts, sodium double chalcogenides. Although the article Triclinic crystal system exists, it is not so useful to have list of triclinic minerals or even less useful list of triclinic compounds. Such lists should be made if others have published this sort of list. However a category of "carbon compounds" is not much use at all. Graeme Bartlett (talk) 04:46, 15 March 2018 (UTC)
I agree with the reply above. I also come up with some new ideas. Maybe some physical properties are more important than the history of chemical compounds. Do you think categorizing the chemical compounds by their colors, solubilities, crystal structures (space groups), melting/boiling points, etc. are the good idea? Subcategories can be created if there are too many. --Leiem (talk) 05:02, 15 March 2018 (UTC)
I do not think that categorizing chemicals by colors, solubilities, or crystal structures (space groups) is a good idea. For dyes, classifing by colour may make sense. But so many chemicals are white, or have colour when impure that it is not useful. For boiling point I have been putting some into the category:gases. But this gets into a grey area when you approach standard conditions boiling point. Finer subdivisions of boiling temperature will probably not be useful to any. Instead make a list of chemicals by boiling point and stick to stuff boiling below 40°. Also a list of high boiling point materials, say over 3000° may be useful. But a list of organic chemicals boiling somewhere between 50° and 200° not so much. Similarly for melting points, a category categorised by temperature subdivisions is not useful, but a list by melting point is more useful. Some substances are categorized by melting point of one of their derivatives, the reason being that melting points measured get depressed by impurities. Crystal form is often used for sorting out minerals, but not for random chemicals. Graeme Bartlett (talk) 06:46, 15 March 2018 (UTC)
Simple: WP:CATDEFINING says content categories are only allowed for defining properties. - DePiep (talk) 11:36, 15 March 2018 (UTC)
Continued at #Wikidata: March 2018 state of matter, since the thread it has become more generic re Wikidata. -DePiep (talk) 08:19, 20 March 2018 (UTC)

Merger discussion for Vitamin B3

An article that you have been involved in editing—Vitamin B3—has been proposed for merging with another article. If you are interested, please participate in the merger discussion. Thank you. SusanLesch (talk) 14:22, 30 April 2018 (UTC)

Strychnine CAS number

The CAS number at strychnine for the sulfate form is a deadlink, but I don't know how to fix it. SpinningSpark 22:28, 6 May 2018 (UTC)

Many CAS number external links are dead (no hit). I guess the CAS database is not open, only a subset is. - DePiep (talk) 22:33, 6 May 2018 (UTC)
The first number is confirmed at chemspider and pubchem, so it is probably correct. Graeme Bartlett (talk) 22:40, 6 May 2018 (UTC)
Both correct. I have checked it in SciFinder database. --Leiem (talk) 12:53, 7 May 2018 (UTC)
@Spinningspark, DePiep, and Graeme Bartlett: A good source to check CAS number is ChemIDplus. See here. I can only propose you to use that website as target for CAS number links inside WP. Snipre (talk) 14:46, 8 May 2018 (UTC)

Wikidata: March 2018 state of matter

Split into new section from #Related categorization. Has now grown into a status of chemicals in Wikidata (e.g., Snipre reply). -DePiep (talk) 08:19, 20 March 2018 (UTC)
  • As an aside. In these days of wikidata how easy is it to do this sort of thing automatically? Chembox data is supposed to be machine friendly. As a progression of this, if such lists can be generated by a simple search do we still need to make them into categories?--Project Osprey (talk) 09:45, 15 March 2018 (UTC)
Using {{Chembox}}, smart searches (eg using WP:PETSCAN, WLH) can be done, producing a linklist of articles to be categorised in a second step. Don't forget {{Infobox drug}} for certain parameters.
Using Wikidata: sure, SPARQL is the query language for WD, but only for data that is in WD already. So the question would be: what chembox data is in WD, is it trustworthy, how to use it (and what if it differs from enwiki?). AFAIK, WD chem people are busy trying to get the ortography right first (for fully automated infobox in the end). That is: relations between chemical compounds.
Third option: in {{Chembox}} read WD, then categorise. Already done for E number and ECHA infocard.
In general, best to think of what we should to categorise first. - DePiep (talk) 11:36, 15 March 2018 (UTC)
@DePiep: Some answers:
  • "what chembox data is in WD": have a look at this page to know what kind of data is available in WD. This list is not up-to-date but lists the main properties related to chemicals. And if you need more data, just ask: the chemistry project can support the property creation if the scope is well defined before the proposal is launched.
  • "is it trustworthy": jut define what is trustworthly. Once again, you can filter data according to their reference. But you have to define what are the trustworthly references. The problem of reference is not from WD side (if a data has no reference or a bad reference according to your criteria, nobody forces you to display hte data in your wiki). You can use WD even when you require high quality data: if you want to have only the data from the diferent editions of the CRC handbook, you can do it with WD. The only thing to do is to create the corresponding lua template in your wiki. So once again the problem is not WD, but the unability of your wiki to generate the corresponding template.
  • "how to use it" and "what if it differs from enwiki": always the same problem. Somebody has to create a lua template in en:WP following the en:WP policy about WD data. So if en:WP policy is very complex, then the template will be very difficult to write.
The good question is more a question of metrics: which database (WD or en:WP) offers the largest set of data like for example which percentage of chemicals has a CAS number/InChIKey/PubChem CID/boiling point/... with a reference. Snipre (talk) 02:05, 20 March 2018 (UTC)
Thanks for this reply. I have moved it into an ==-level section, as it nicely opens about current Wikidata options. The previous subsection was about "Should we categorise by year of discovery?". -DePiep (talk) 08:22, 20 March 2018 (UTC)
Some 15 months ago we discussed WD development re {{Chembox}}. I remember it was about othography first (family relations between chemical compounds, groups, etcetera.). With that model set in WD, an automated infobox could be created (like those in gene/protein, IIRC). Of course, many incongruencies appear between {{Chembox}} and {{Infobox drug}} versus the WD data(-model). As for me, this orthography is out of my league so I could not contribute in there.
Sure properties and identifiers are in WD, sourced or even well-sourced. And already today, E number and ECHA infocard are read in from WD unrestricted (see tracking Category:Chemical compounds and Wikidata, for both infoboxes). Contrary to what you write, it did not require Lua encoding, not even {{Infobox}} as {{Chembox}} is still in wikitable format :-).
re "the unability of your wiki to generate the corresponding template": contrary to what you seem to think, it's not about waiting for that solve-everything Lua infobox: before, some policy has to be established. That is, consensus on what data to use, and how to present it. In this policy, some trust questions will be asked. (IOW, enwiki editors somehow need to be convinced). For example with {{Infobox_medical_condition}}, I remember there was strong objection to blindly read & show WD data. It boils down to what I wrote: better first think about what to use from WD.
Then there is this about data quality & improvements on WD. Quite often when working on WD I've only met snubs, disinviting any cooperation. For example standard atomic weight (s.a.w.), and this is serious. I have tried to get the correct s.a.w. into WD as a property; that failed. So far, this property is unusable and enwiki has created its own well-sourced set (compared Template:Infobox element/symbol-to-saw/testcases-wikidata). For example with neon, WD says: P2067 mass = 19.992±0 atomic mass unit; source is PubChem. E-ve-ry-thing in this statement is wrong, for over 15 months. "Mass" has SI-dimension 'mass' (but atomic weight is dimensionless, aka 'relative'); it has a unit added (dimensionless so unit is absent or "1"); the number is wrong; the uncertainty is wrong; the source is not the the source for standard atomic weight ([1][2] is); other elements like H, C have an interval notation for uncertainty not "±"; and elements without s.a.w. still can a value added here (not today BTW). A consequence is that any molar mass derived from this value is wrong (skipping the thought that neon is inert: the issue may apply to all elements). Also, since PubChem has published this value, likely all PubChem published molar masses are to be distrusted. In general: it is not possible to pull out of WD the correct, trustworthy s.a.w., and so are any (weight) calculations performed from these. - DePiep (talk) 09:47, 20 March 2018 (UTC)
@DePiep: You don't need lua template to use WD data but you need a lua template if you want to filter the data according to their references or other criteria like the definition of some qualifiers. Some lua modules can help you to filter WD data according to the presence or not of a reference (depending on your modules development) but if you want to filter according to a defined set of references, then you need an upgraded programming.
"there was strong objection to blindly read & show WD data": Just create your filter according to what you want to show. This can be done by a lua template in en:WP. So you are right saying "what" is the first question, but the question is not "what to use from WD" but "what to show in en:WP". Once you know what you want to show, you can program a lua template which respects these constraints and will extract data from WD according to these constraints. You should have the same rules for data independently from their origin, WD or WP wikitext. You want to have data from high quality references ? Well, not a problem but how do you manage that constraints in WP now ? You want to show only solubility data with solvent definition AND measurement temperature ? WD can filter the data according to that condition.
You are right concerning the fact that the data model for some properties is not correct, but the main reason is the lack of resources to correct contributor's errors and bad use of properties. There are less than 5 active contributors in the WikiProject Chemistry and we can't do everything and at the same time thousands of contributors are trying to add data with a poor knowledge of data modeling or accurateness. So we are trying to curate data but this takes time. And for your aborted proposal, better have a long discussion with the Wikiproject chemistry in order to get full support of some contributors before starting the process. Property proposal is a boring process and few persons spend a lot of time to understand and to challenge a property. Snipre (talk) 16:37, 20 March 2018 (UTC)
thx again for yr reply and yr kind patience. Will dive in later. -DePiep (talk) 18:54, 20 March 2018 (UTC)
I don't want to convert you to WD, I just like that people have a clear idea of what is WD and what WD can propose. There are plenty of good reasons to avoid to use WD, but bad quality data is not a good one because WD allows you to filter the data and to remove what you don't want. WP:en perhaps has already the corresponding function for extraction of value with references. Have a look at the documentation of module:wikidata or an associated function. In any case, this should be simple to implemented as the french version of module:wikidata has this function "withsource". Snipre (talk) 21:14, 21 March 2018 (UTC)
I think it would be nice if we could use Wikidata. But what is happening is that there is now added complexity beyond what most of our contributors can understand. The main problem I see is duplicates in the Wikidata space. There are a few errors in data, but similar to Wikipedia, and probably reflects errors or confusion in sources like PubChem anyway. If we could have a tool to help with chemboxes to show someone that adds a chembox, what data would be filled from Wikidata, and what it is based on, and then an opportunity to correct the Wikidata, then it would help. Graeme Bartlett (talk) 01:52, 29 April 2018 (UTC)

References

  1. ^ CIAAW
  2. ^ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
@Graeme Bartlett: There is no problem of complexity if you switch the current infobox to a lua infobox designed to handle both WD data and wikitext data. So the complexity is switched to the infobox coding and not to the infobox filling by contributors. If the lua chembox is well done, you just copy/paste like now the wikitext of the chembox and the code checked the presence of data in the wikitexte and if not will retrieve data from WD. So people can always add data in the wikitext like they are doing now. Snipre (talk) 14:48, 9 May 2018 (UTC)

Merger discussion for Nitrogen monohydride/Imidogen

articles that you have been involved in editing—Nitrogen monohydride and Imidogen—have been proposed for merging with another article. If you are interested, please participate in the merger discussion. Thank you. --Dirk Beetstra T C 06:53, 10 May 2018 (UTC)

Titanium silicon carbide

I have created the article "Titanium silicon carbide". Please expand it. Axl ¤ [Talk] 12:02, 17 May 2018 (UTC)

If an article is worth creating, it almost certainly should be supported by a WP:SECONDARY or WP:TERTIARY reference. Such references are the foundation. --Smokefoot (talk) 13:13, 17 May 2018 (UTC)
Wow! That's a particularly unhelpful response. Axl ¤ [Talk] 17:40, 17 May 2018 (UTC)
It means that you should be using reviews like https://doi.org/10.1179/1743280410Y.0000000001 . If you just use primary references you may miss something that has been proved wrong or include something of no importance. Once an independent person has commented on that other primary research you can get a more balanced view. There do seem to be several writing on materials science aspects, including its handling of radiation. PubChem and ChemSpider have not indexed this substance, so I won't bother with a chembox! Graeme Bartlett (talk) 22:48, 17 May 2018 (UTC)

3DMet update

The 3DMet maintainer has contacted me again. The 3DMet site has been updated with a new release. There is still a non-fatal javascipt error that hopefully will be gone soon. The previously found errors in 3DMet entries are almost all fixed, but they came with new numbers. I have gone through the Wikipedia pages and changed them to point to correct 3dmet entries. Note that KEGG still refers to wrong entries, so please check before copying from KEGG. They still want to know about errors in the displayed pages. (eg nitric oxide http://www.3dmet.dna.affrc.go.jp/cgi/show_data.php?acc=B00122). So it is probably safe to add 3DMet entries again to Chembox Identifiers. Graeme Bartlett (talk) 11:58, 18 May 2018 (UTC)

D-ascorbic acid

The redirect D-ascorbic acid, which currently targets Vitamin C, has been nominated for deletion at Wikipedia:Redirects for discussion/Log/2018 May 19#D-ascorbic acid. You are invited to contribute to that discussion as comments from those who understand the subject would be beneficial. Thryduulf (talk) 12:57, 19 May 2018 (UTC)

Please clean Tetrahydrofolic acid

Currently the UPAC name in the infobox refers to (2S)-2-{[4-({[(6S)-2-amino-4-oxo-1,4,5,6,7,8-hexahydropteridin-6-yl]methyl}amino)phenyl]formamido}pentanedioic acid or (2S,6S)-5,6,7,8-tetrahydrofolic acid but all identifiers refers to (2S)-5,6,7,8-tetrahydrofolic acid. Please check what is the appropriate IUPAC name and change the Wikidata link if necessary. And please check the chemical structure displayed in the infobox: 2 chiral atoms are defined in the chemical structure.

DB 5,6,7,8-tetrahydrofolic acid (2S)-5,6,7,8-tetrahydrofolic acid (2S,6S)-5,6,7,8-tetrahydrofolic acid
InChIKey MSTNYGQPCMXVAQ-UHFFFAOYSA-N MSTNYGQPCMXVAQ-KIYNQFGBSA-N MSTNYGQPCMXVAQ-RYUDHWBXSA-N
DrugBank - 00116 02031
PubChem 1129 91443 5460413
Wikidata Q168453 Q53668656 Q27098158
ChEBI - 20506 15635
CAS 29347-89-5 135-16-0 -

Snipre (talk) 21:43, 20 May 2018 (UTC)

Splitting BPA into Bisphenol A and Bisphenol A controversy

Bisphenol A is a commodity chemical that has gotten a lot of press, mainly for its possible connection to endocrine disruption. The article is almost unwieldy in size, so I started a sparsely commented-on suggestion to split. Which really means split-off most of bio-medical-enviromental controversy. So I was going to call the daughter article Bisphenol A controversy. But some might perceive that title to be pejorative. Suggestions welcome.--Smokefoot (talk) 21:19, 26 May 2018 (UTC)

WikiProject Polymers

Wikipedia:WikiProject Polymers appears to be inactive, with no responses to inquiries on their talk page for some years. They have a number of articles assigned to them through the usual talk-page tag. Most (all?) of these pages also fall under the scope of this project. What I'm wondering is can we and should we adopt those pages to the extent that they appear on our article alerts and hence receive some basic curation? --Project Osprey (talk) 22:33, 26 May 2018 (UTC)

Giving WP Chemicals the alerts would be a good idea. I have tagged a few pages with Polymers project, but should I just add WP Chemicals instead? Graeme Bartlett (talk) 22:54, 26 May 2018 (UTC)
Yes, unless there's another way of doing it. What I don't know is how is generate a list of articles which are only tagged as belonging to WP:polymers. If we had that we could just add ourselves using AWB (I think..) --Project Osprey (talk) 23:30, 26 May 2018 (UTC)
PetScan will do the job: 874 are as you describe https://petscan.wmflabs.org/?language=en&project=wikipedia&categories=WikiProject%20Polymers%20articles&negcats=WikiProject%20Chemicals%20articles%7C2&interface_language=en&active_tab=&doit= . There are 687 if we exclude Chemistry[3], and 671 if MCB is excluded[4]. Graeme Bartlett (talk) 09:29, 27 May 2018 (UTC)

We may not have the critical mass to have that separated as a project, but there maybe an advantage to keep it separated. Maybe we should foster this child under this project, I’ve watchlisted the project. —Dirk Beetstra T C 03:58, 27 May 2018 (UTC)

Now why didn't I think of that? That'd be even easier. Watchlisted also.--Project Osprey (talk) 21:45, 27 May 2018 (UTC)

Any objections against marking the Wikipedia:WikiProject Polymers as 'being fostered by Wikipedia:WikiProject Chemicals' for 'bookkeeping reasons'. I'll point the Wikipedia talk:WikiProject Polymers to this discussion. --Dirk Beetstra T C 06:08, 28 May 2018 (UTC)

WikiProject collaboration notice from the Portals WikiProject

The reason I am contacting you is because there are one or more portals that fall under this subject, and the Portals WikiProject is currently undertaking a major drive to automate portals that may affect them.

Portals are being redesigned.

The new design features are being applied to existing portals.

At present, we are gearing up for a maintenance pass of portals in which the introduction section will be upgraded to no longer need a subpage. In place of static copied and pasted excerpts will be self-updating excerpts displayed through selective transclusion, using the template {{Transclude lead excerpt}}.

The discussion about this can be found here.

Maintainers of specific portals are encouraged to sign up as project members here, noting the portals they maintain, so that those portals are skipped by the maintenance pass. Currently, we are interested in upgrading neglected and abandoned portals. There will be opportunity for maintained portals to opt-in later, or the portal maintainers can handle upgrading (the portals they maintain) personally at any time.

Background

On April 8th, 2018, an RfC ("Request for comment") proposal was made to eliminate all portals and the portal namespace. On April 17th, the Portals WikiProject was rebooted to handle the revitalization of the portal system. On May 12th, the RfC was closed with the result to keep portals, by a margin of about 2 to 1 in favor of keeping portals.

There's an article in the current edition of the Signpost interviewing project members about the RfC and the Portals WikiProject.

Since the reboot, the Portals WikiProject has been busy building tools and components to upgrade portals.

So far, 84 editors have joined.

If you would like to keep abreast of what is happening with portals, see the newsletter archive.

If you have any questions about what is happening with portals or the Portals WikiProject, please post them on the WikiProject's talk page.

Thank you.    — The Transhumanist   10:54, 31 May 2018 (UTC)

Special:Contributions/Rirai1973

The user massively adds log P data taken from ChemSrc. I didn't know this website before, but at least in the case of Octamethylcyclotetrasiloxane and Decamethylcyclopentasiloxane, the values were off by several log units compared to currently scientifically accepted values. My other concern is that partly way too many significant digits are being added. --Leyo 09:35, 30 May 2018 (UTC)

Inviting Rirai1973 - DePiep (talk) 15:58, 30 May 2018 (UTC)
No response by the user. No reaction by other users here, either. --Leyo 09:31, 6 June 2018 (UTC)
I've never heard of ChemSrc before and having checked the website I don't think they're the kind of source we should be using. I expect a mass deletion may be in order. --Project Osprey (talk) 09:41, 6 June 2018 (UTC)
I've posted a request for a response on their talk page to see if we can find out what's happening. Walkerma (talk) 15:03, 6 June 2018 (UTC)

EDTA

IMHO it is inappropriate for a compound with 4 carboxylic acid and 2 amine groups to indicate one pKa and one pKb only. However, I haven't found a reliable reference for all six values. BTW: There is a request on a similar matter on the talk page. --Leyo 12:41, 26 June 2018 (UTC)

Might be some answers here, if you can get into it doi:10.1021/ac60215a006. --Project Osprey (talk) 14:48, 26 June 2018 (UTC)
Thanks, but I don't have access to the full text. --Leyo 15:53, 26 June 2018 (UTC)
The answers are not in that. But it does say as acid is added the two amine groups are protonated first. In stronger acids, the carboxylate groups would be protonated, but there is nothing on those measurements. no pKa or pKb values are there. DOI: 10.1021/ja00902a016 also is on a similar topic. Graeme Bartlett (talk) 00:32, 27 June 2018 (UTC)
I don't have access to that one either. Values are given e.g. there, but this reference is certainly not usable. --Leyo 08:18, 27 June 2018 (UTC)
SciFinder has nothing, in case your wondering. --Project Osprey (talk) 08:19, 27 June 2018 (UTC)
An anwser is in Quantitative Chemical Analysis, 8th Edition by Daniel C. Harris published by W. H. Freeman in 2010 ISBN: 1429218150, or 9781429218153 page 240: It has pKa values of 0.0, 1.5, 2.00, 2.69, 6.13, 10.37 - conditions 25° concentration 0.1 M (except the 0.0 value is at 1 M). It claims that the first 4 pKas are deprotonating carboxylic acids, and the last two the amines. Graeme Bartlett (talk) 11:03, 28 June 2018 (UTC)
Surely the first 2 would be amines (well, ammonium → amine)? --Project Osprey (talk) 12:10, 28 June 2018 (UTC)
Well it is consistent with the reference you presented above. Graeme Bartlett (talk) 06:46, 29 June 2018 (UTC)
hmm... zwitterions I guess, which must made the order of protonation rather complex (I can't actually get into either ref).--Project Osprey (talk) 08:16, 29 June 2018 (UTC)
According to ACD/Labs pKa GALAS module, the species with all carboxylic acid groups deprotonated and both amine groups protonated is the most prevalent one between pH 2.6±0.5 and 7.8±0.6.
The pKa values estimated by ACD/Labs pKa GALAS module are 0.7±0.4, 1.3±0.4, 1.9±0.5, 2.6±0.5, 7.8±0.6, 11.0±0.4. The first four COOH/COO−, the last two NR3H+/NR3. --Leyo 09:11, 2 July 2018 (UTC)
Thanks. IMHO a pKa is independent of the molarity. Hence, I guess these values may be added to the article. --Leyo 21:59, 28 June 2018 (UTC)

Benzoin (organic compound)?

@SilkTork: Benzoin is now Benzoin (organic compound) with no discussion. Seems like a change that should get consensus. --Smokefoot (talk) 12:19, 9 July 2018 (UTC)

My checks into this indicated that the move was uncontroversial. There is a slight possibility that the resin is primary but neither books, Google, page links, nor page views indicated sufficiently that it was, so a disamb page was the most appropriate. Page views for the compound have now dropped from a daily average of 126 to 55, but it's too early to indicate if this is just a blip as page views can vary, and even then, I'm not entirely sure that the other evidence is sufficiently strong for the resin to be considered the primary topic. A disamb page looks the most appropriate according to our guidelines, but if you have evidence that either the resin or the compound is the WP:PRIMARYTOPIC, then you can put it here, or open a WP:RM#CM. SilkTork (talk) 12:59, 9 July 2018 (UTC)

Monoiodotyrosine vs. 3-Iodotyrosine

May these two articles get merged? At least, the chemical structure presented in the infobox is identical. --Leyo 20:21, 17 July 2018 (UTC)

Yes it appears to be a good idea. Wikidata needs merging too with interwiki transfer. Graeme Bartlett (talk) 02:15, 18 July 2018 (UTC)
Which is the preferred title for the article?
@Beetstra, Edgar181, Project Osprey, and Medgirl131: You've contributed to one of the articles and may have an opinion concerning a possible merger. --Leyo 20:09, 18 July 2018 (UTC)
I agree that the two pages should be merged. I prefer the title "3-Iodotyrosine" because "Monoiodotyrosine" is ambiguous. -- Ed (Edgar181) 20:13, 18 July 2018 (UTC)

3-Iodotyrosine, more complete. Make the other a redirect. --Dirk Beetstra T C 20:54, 18 July 2018 (UTC)

I'm also in favour of a merge... however the articles have different CAS numbers, which should not be possible. A possible answer can be found in their associated wikidata entries: Monoiodotyrosine → wikidata:Q410703 (3-Iodo-L-tyrosine), 3-Iodotyrosine → wikidata:Q410703 (3-iodo-DL-tyrosine). I can't currently check that out but it would need to be cleared up in the merge. --Project Osprey (talk) 21:38, 18 July 2018 (UTC)
According to Chemical Abstracts, 70-78-0 is the CAS# for 3-Iodo-L-tyrosine (S-enantiomer), 25799-58-0 is the CAS# for 3-Iodo-D-tyrosine (R enantiomer), and 3078-39-5 is the CAS# for 3-Iodotyrosine (unspecified stereochemistry). 29592-76-5 is the CAS# for monoiodotyrosine with unspecified position of substitution and unspecified stereochemistry. -- Ed (Edgar181) 11:41, 19 July 2018 (UTC)
I have now merged the two articles into 3-Iodotyrosine. Currently, the Wikidata page that connects to the 3-iodotyrosine page is the one for the L-isomer, which is appropriate I think because the article content is specific to that isomer. I removed the link to the new redirect at monoiodotyrosine from the other Wikidata page because it is no longer relevant. -- Ed (Edgar181) 12:02, 19 July 2018 (UTC)

Dimanganese decacarbonyl

Would someone please check diff and revert if warranted. It doesn't make sense to me but the IP's edit summary has me bluffed. The immediate problem is that MeltingPtC has to be empty or a pure number. Use MeltingPt for text like "sublimes". Johnuniq (talk) 07:31, 22 August 2018 (UTC)

Reverted. Previous matches with chemspider and subliming isn't melting, it is boiling Galobtter (pingó mió) 07:37, 22 August 2018 (UTC)

Perfluoroether vs. Perfluoroalkoxy alkane

Wouldn't Perfluoroalkoxy alkane fit better into d:Q7168156 d:Q145925 than Perfluoroether? --Leyo 22:00, 6 September 2018 (UTC)

I'm not sure I understand the question correctly. d:Q7168156 relates to Perfluorobutanesulfonyl fluoride, which would be a bad fit for either of the compounds you've given. --Project Osprey (talk) 08:33, 7 September 2018 (UTC)
I had too many tabs open and picked the wrong item (now corrected). --Leyo 09:01, 7 September 2018 (UTC)
So you wish to combine the wikidata pages under d:Q145925 (Perfluoroalkoxy)? I see no reason not to, they are fairly similar and at the moment their wikidata pages hold minimal data. A pedantic point: perfluoroalkoxy is an incomplete chemical name, perfluoroether might be a better description. --Project Osprey (talk) 09:11, 7 September 2018 (UTC)
The English label of d:Q145925 may be changed to perfluoroalkoxy alkane. --Leyo 23:44, 7 September 2018 (UTC)

Redirects with unmatched closing parentheses

I've found that there are at least 5 redirects with unmatched closing parentheses in the middle of a chemical name -

Are these correct chemical names or are they missing something? If the latter I intend to nominate them for deletion unless there is some other reason why they are worth keeping. Thryduulf (talk) 09:10, 21 September 2018 (UTC)

The IUPAC nomenclature of inorganic chemistry 2005 (Red Book) [5] has no mentioning of unbalanced brackets. So these five incidents are typo's (misspelled names). I have no impression that these are a likely misspelling, so WP:R#DELETE is applicable. But maybe other CHEM editors have a more complete overview of usage. -DePiep (talk) 11:37, 21 September 2018 (UTC)
None of them are valid chemical names as is, but they all would be if they had matched parentheses. -- Ed (Edgar181) 11:58, 21 September 2018 (UTC)
Do you suggest to movethese Redircts to the proper-bracketed form (with target page unchanged)? Quite reasonable, as alternative name. Then delete the wrong name. -DePiep (talk) 12:02, 21 September 2018 (UTC)
@DePiep: if the correct names do not already exist (as I don't know what they are it's difficult for me to check), then the simplest thing is to just create redirects from that title. Thryduulf (talk) 12:09, 21 September 2018 (UTC)
They do no harm titled as they are, but might be of marginal benefit if fixed. Each would just need an open parenthesis at the beginning. -- Ed (Edgar181) 12:13, 21 September 2018 (UTC)
Shortcut home: Proper name is with opening bracket in front. 1. if not exists, move bad name to good name & keep redirect target. 2. If good name exists: check target name. 3. Delete all bad name redirects (speedy or RfD), as they are not wotrth keeping. 4. Enjoy weekend. -DePiep (talk) 13:07, 21 September 2018 (UTC)
Only two exist, but they are both set indexes that don't mention the current target:
I'll move the others to the titles beginning with a (. I'll wait on nominating at RfD until the other two are sorted so I can do them as a single batch. Thryduulf (talk) 17:57, 21 September 2018 (UTC)
I deleted all the incorrect redirects. The other issue may be solved independently. --Leyo 21:31, 7 November 2018 (UTC)

Ammonium sulfide

The diammonium salt is presumably fictitious, which I tried to emphasize in that article. But others might have views on this material. I am considering redirecting ammonium sulfide to ammonium hydrosulfide, which could have a subsection on the impossibility of the diammonium salt.--Smokefoot (talk) 15:56, 23 August 2018 (UTC)

@Smokefoot: I noticed that the compound was registered as an intermediate in the EU. --Leyo 09:26, 9 November 2018 (UTC)
As you would probably agree, the EU probably does not listen to editors on Wikipedia. Also, there is no harm having articles on compounds whose existence is uncertain. The existence of (NH4+)2S2- seems unlikely or impossible, but the existence of a composition (NH3)2H2S could be real. The material is probably a solution, not purified. But these are my OR-ish thoughts. --Smokefoot (talk) 11:24, 9 November 2018 (UTC)
This paper would seem to confirm that diammonium sulfide cannot form by simple mixing (disclaimer: I can only see the abstract) doi:10.1021/ic50051a002. --Project Osprey (talk) 15:53, 9 November 2018 (UTC)
It says in the paper that the amount of S2− can be neglected since no K2S is formed upon addition of potassium, so the only sulfur anion present in substantial amounts is HS−. --Andif1 (talk) 16:37, 9 November 2018 (UTC)

Editors in this WikiProject may be interested in the featured quality source review RFC that has been ongoing. It would change the featured article candidate process (FAC) so that source reviews would need to occur prior to any other reviews for FAC. Your comments are appreciated. --IznoRepeat (talk) 21:52, 11 November 2018 (UTC)

1,1,1-Trifluoro-2-chloroethane

According to PubChem and ChemSpider the correct IUPAC name is “2-chloro-1,1,1-trifluoroethane”. Is there any reason not to move the article? --Leyo 23:05, 6 November 2018 (UTC)

 Done --Leyo 00:29, 20 November 2018 (UTC)

Chembox taskforce

Looking for people interested in helping out with converting {{Chembox}} to use {{Infobox}}. Anyone interested in taking part, please drop a line here. Thanks! --Zackmann (Talk to me/What I been doing) 18:51, 20 November 2018 (UTC)

FRD-903

The density and the pKa in the chemobox seem to refer to the ammonium salt FRD-902, not FRD-903 (see page 19, i.e. page 21 of the PDF). The pKa might, however, be valid for the acid form as well. May it be kept? --Leyo 10:08, 14 December 2018 (UTC)

Category:PBT substances

This new category contains a single article. If there are no reservations against it, all fitting articles would need to be added (see de:Kategorie:PBT-Stoff). --Leyo 00:32, 20 November 2018 (UTC)

PBS would seem pass any normal bar for inclusion. looks like it overlaps in part with Category:Persistent organic pollutants. --Project Osprey (talk) 10:02, 20 November 2018 (UTC)
I don't think that having the ambiguous Category:Persistent organic pollutants is a good idea. It would be enough to keep its subcategories. They do partially overlap with Category:PBT substances, but this is on purpose. --Leyo 12:19, 20 November 2018 (UTC)

@DinosaursLoveExistence: As the creator of the category, are you going to add the PBT substances in this list (if they have an article) to that category? --Leyo 17:39, 21 December 2018 (UTC)

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