Wikipedia talk:WikiProject Chemistry/Archive 42

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Cyclopropenium ion

Will someone please take another look at Draft: Cyclopropenium ion? A reviewer is currently looking at it. It appears to be the work of one person who has not been working on anything else. Robert McClenon (talk) 16:39, 15 May 2017 (UTC)

Also, will someone please review Draft:Hydrogen-bridged cations? These may be two papers from one class, since they both have to do with distributed positive charge. Robert McClenon (talk) 16:46, 15 May 2017 (UTC)
Notice that almost all the artwork in Hydrogen-bridged cations looks copied (to use the polite term). Please do not accept.--Smokefoot (talk) 16:53, 16 May 2017 (UTC)
Are Cyclopropenium ion and Cyclopropene the same thing? There is a confusing web of redirects to and from apparent synonyms between these two articles (use "What links here" to find them) Some cleaning up, if not an merge, is probably needed to straighten out the various links. I'm afraid as the accepting reviewer of "Cyclopropenium ion" I may have contributed to the tangle. Roger (Dodger67) (talk) 17:00, 15 May 2017 (UTC)
User:Dodger67 - No. Cyclopropene and Cyclopropenium ion differ by one electron, and that does make a difference. Cyclopropene is a neutral compound. Cyclopropenium has lost an electron and is positively charged. The charge is delocalized, and for complicated reasons that increases its stability. But they are closely related. Robert McClenon (talk) 15:21, 16 May 2017 (UTC)
talk - Incorrect. Cyclopropene has the formula C3H4, Cyclopropenium ion usually refers to cyclopropenium cation, with the formula C3H3+. --Smokefoot (talk) 16:53, 16 May 2017 (UTC)
My error. That is what I meant, but they differ by a proton and two electrons. Robert McClenon (talk) 05:39, 17 May 2017 (UTC)
These are homework assignments (unsupervised forced labor that produces a crappy essay that impresses editors who know little chemistry). Ideally such articles should not be accepted until Chemistry project reviews them, please do that next time! --Smokefoot (talk) 17:11, 15 May 2017 (UTC)
Smokefoot Unfortunately AFC can't force WikiProject Chemistry members to register as AFC reviewers. The lack of topic specialists doing regular (read "constant") AFC and NPP work is a perennial problem. Roger (Dodger67) (talk) 17:34, 15 May 2017 (UTC)
Well, thanks for checking. I and some colleagues here experience a mixture of joy and anger about these things. On one hand they usually contain valid content, often on topics we welcome, on the other hand they are often poorly constructed and ultraspecialized. Many of us editors feel sudden pressure to make them semi-respectable so that they do not embarrass our project. Cheers, --Smokefoot (talk) 18:47, 15 May 2017 (UTC)
  • I am less pessimistic about class projects, they can grow into quality articles. Cyclopropenium ion is one of them. Remember these are highly specialized topics but they serve a purpose. V8rik (talk) 20:52, 15 May 2017 (UTC)
Draft articles can be spotted along with other new chemistry page creations in User:AlexNewArtBot/ChemistrySearchResult. It updates about 1900 UTC each day. But what are our standards? Essential is no copyright infringement or promotional content. I don't like seeing one liner substubs saying "xyz is a chemical." It is good to have a suitable name, chembox, categories, section headings, wikilinks, talk page with project marked, and definitely factual correctness. Much harder is to improve the quality of references. In the case of Cyclopropenium ion it was originally misleading us in the lede to believe that this ion exists, when only derivatives are known. Graeme Bartlett (talk) 07:52, 16 May 2017 (UTC)
User:Graeme Bartlett - Not directly on the subject of chemistry in sensu stricto, but on the subject of whether the subject exists, I have also been seeing articles on proteins which, it appears from reading, are only predicted based on the DNA. Robert McClenon (talk) 15:30, 16 May 2017 (UTC)
We can certainly have articles on things not yet proven to exist, but it should be clear in the first sentence of the article! Graeme Bartlett (talk) 21:24, 16 May 2017 (UTC)

Draft:Electrochemical Promotion of Catalysis (EPOC)

Please review. Robert McClenon (talk) 03:14, 17 May 2017 (UTC)

checkY accepted. Graeme Bartlett (talk) 04:18, 17 May 2017 (UTC)
Looks pretty weird to me. Indicators from the lede:
  • Begins with emphasizes on (an obscure - non-wikilinked) individuals vs the topic at hand, i.e. promotional "The EPOC effect was firstly discovered by M. Stoukides and C. Vayenas in the early 1980s and ...."
  • Emphasizes research and semi-quantifies numbers of impacts "....have been widely studied by various research groups for more than 100 heterogeneous catalytic reactions of mostly gaseous molecules.[1]"
  • Tells the reader that the topic is important vs letting the topic speak for itself "...The EPOC effect has been evaluated as an important phenomenon which can closely link electrocatalysis and thermal catalysis.[2][3]"
And my old favorite - absence of WP:SECONDARY reference. For articles on phenomena, a review or textbook is almost obligatory.
--Smokefoot (talk) 12:36, 17 May 2017 (UTC)
It strikes me that refs 2 and 3 are reviews. What annoys me is the lack of neutral tone, all versatile and important phrases should be removed. V8rik (talk) 17:10, 17 May 2017 (UTC)

Request corrections in diagrams

Illustration of silylmetalation in the carbometalation article

In the above thread on carbometalation, I noted some issues with the image File:Silylmetalation.png, shown at right and included in the carbometalation article. It was uploaded by V8rik in 2007. It has, amongst other issues:

  • ZnCl as the formula for zinc chloride
  • zinc ions with formal negative charges
  • what could be taken as a magnesium(III) centre in MgCl+
    2    , amongst other issues
  • a potentially-confusing disappearance of ligands around the zinc centre, replaced by bonds which are meant to imply connection to what was there, but which could be taken as methyl groups
  • issues with charge balance
  • some species disappear (like the protons on the 2,2'-dihydroxybiphenyl) but others are preserved (like the Li+)... either have everything unneeded disappear, or show everything, but the combination of both can be confusing
Synthesis of dioscorine from trigonelline

I have also noticed that the File:Highlights of the synthesis of dioscorine from trigonelline.png has mistakes in it. It was uploaded by Renaureal who also wrote the dioscorine article, and has not edited since that day in 2015. According to the article text, the source paper for the diagram is doi:10.1016/0031-9422(88)83019-X and the issues I see include:

  • the arrow-pushing is clearly wrong in both cases where it is used:
    • in the first, the Michael addition (which is missing its base) shows breaking of C—C bond from the reactant where actually the base would deprotonate the acidic hydrogen alpha to the carbonyl and carboxylic acid, which is then the nucleophile that attacks the aromatic ring
    • in the second, the arrows show the formation of product with an oxygen atom surrounded by four double bonds and a lone pair! The bond forming reaction should be from the ring to the carbonyl carbon to form an alcohol moiety (after protonation) and a bridge-head.
  • the product of the decarboxylation step has lost two carbons...
    • the methine (technically a methanetriyl) to which one of the carboxylic acid groups is attached should become a methylene, but instead it disappears only to reappear in the subsequent structures (ie. the β-imino acid has N—ring methine—methine α to carboxylic acid—ketonic carbon... after decarboxylation, this should become N—ring methine—methylene—ketonic carbon but instead becomes N—ring methine—ketonic carbon
    • the methyl side chain on the alkene disappears and then re-appears
  • the species labelled as an imino acid is actually not an imino acid, having no C=N moiety
  • the product from the second set of arrow-pushing should have a C=C bond and a C=N+ bond in the ring system, but the C=C bond has been hydrogenated (somehow) to a single bond
  • the arrows going to the dumetorine side product (found in the yam Dioscorea dumetorum): the first is unlabelled, the second reads "Further" and "lactone formation", but the second step is lactone formation and nothing else. I suggest the first arrow read something like "hydrogenation (multiple steps)" and the second read simply "lactone formation" or "lactonisation."
  • the arrow leading to dioscorine product reads "Reaction of iminium ion with lactone", but actually the reaction produces a lactone and also involves reduction of the iminium ion to a tertiary amine. I suggest a label like "Reduction and lactonisation."

The dioscorine article is also not formatted along the lines typical of a chemical article (infobox etc) and has seen little editing since its formation. I haven't looked through it in any detail (I was adding links to catharanthine when I found it as part of a DYK issue, so any editing would be welcome. In addition, new versions of these two images are needed. Maybe not everything I have noted will be seen as a problem by other editors, but I do believe that some adjustment is necessary. Thanks. EdChem (talk) 23:23, 17 May 2017 (UTC)

V8rik has contributed so much but must have thick skin by now. So if a figure is flawed, I recommend moving it to Talk or removing it. Most readers, me included, look mainly at images and ignore text. So getting the images right is important. There has also been a trend toward keeping words out of images so that the resulting figures can be more useful in other language wikis. --Smokefoot (talk) 00:24, 18 May 2017 (UTC)
I looked at the Phytochem paper on the natural product. Here is a very simplified scheme. I think that we might spare readers of arrow pushing (which is kinda out of date anyway). But please advise while I have the artwork on my desktop. --Smokefoot (talk) 00:53, 18 May 2017 (UTC)
Smokefoot, on your diagram, the positive charge should be on the N and not the Me, there is a double bond in the reagent and intermediate missing, and this version gives no indication of the side reaction. EdChem (talk) 02:15, 18 May 2017 (UTC)
Improved image. If you really want the + next to N I can do that, but it is also common (as in NMe4+ to put charge next to alkyl). --Smokefoot (talk) 02:53, 18 May 2017 (UTC)
biosynthetic scheme
Smokefoot, thanks. The placement of the plus isn't that important. There is one thing that bothers me, though, and I notice it is in the original too... the stereochemistry of the alkene goes from (Z) to (E) for no apparent reason – would you please check if that happens in the paper (in which case we accept it, obviously), or whether the substituted hept-2-en-dioic acid had an (E) stereochemistry? Thanks. EdChem (talk) 03:59, 18 May 2017 (UTC)
OK this is more work than just drawing. I had assumed that you knew the structures. In any case, the attached is closely modeled after the Phytochem paper. --Smokefoot (talk) 13:52, 18 May 2017 (UTC)
This thread once again proves that peer review on chemistry images takes on average 10 years! I have reviewed the case and decided to remove the entire section. V8rik (talk) 17:34, 18 May 2017 (UTC)

Hover text

We are missing hover text, probably after making whole cells clickable. Example: Template:Extended periodic table (by Fricke, 32 columns, compact). --Obsuser (talk) 03:28, 6 May 2017 (UTC)

With me they show OK. That's Firefox here, in a desktop view. To be clear: when hovering a cell with the mousepointer in the periodic table, we expect a mouse-tooltip appearing: cell "I" shows tooltip "Iodine" (which is simply its wikilink target page). Just as we expect this for any wikilink in text. CSS-formally this is called the 'title' btw. -DePiep (talk) 13:50, 8 May 2017 (UTC)
@DePiep: Thing is that there are no hover descriptions when you move cursor from the link itself to the field: for example "Beryllium: alkaline earth metals; primordial; solid". Compare 121 and 124 in {{Extended periodic table (by Fricke, 32 columns, compact)}}.
Or it was intentional because iodine link was too narrow? --Obsuser (talk) 17:25, 16 May 2017 (UTC)
Yes a few months ago we made the whole cell click-sensitive (while showing the wikilink regular). It was searched for the small "I" (iodine) character, but applied to all element cells. With this, the tooltip (css-title) shows when the cell is hovered -- at least, intended & expected & ok with me here.
With Be I get css-title "Beryllium" (but not its properties you listed). With E121 "Unbiunium" OK. But E124 is not linked, and only says property "(superactinide)" (This is a bit weird agree, but not the issue here).
So, looks like the problem is still: I cannot reproduce the bug you describe. How does {{Periodic table}} function for you? (with me: OK too) -DePiep (talk) 18:39, 16 May 2017 (UTC)
Big ones are good, this one that I was complaining about and maybe some similar if eongf oist are not (it is "weird" i.e. has no consistency, properties are not shown). Not a big issue, small one, like a suggestion. --Obsuser (talk) 19:24, 19 May 2017 (UTC)
If it does not work as intended ... it is relevant ;-). What browser are you using? Does the error happen on desktop screen, or in mobile view? -DePiep (talk) 21:51, 19 May 2017 (UTC)

Definition of Macrocyclic Ligand

I searched for a source how macrocyclic ligand is actually defined. In the wikipedia article there is the IUPAC Gold Book as a source. However, I didn't find a definition there for macrocyclic ligand. Neither in my downloaded pdf (Version 2.3.3, 2014-02-24) nor on the website http://goldbook.iupac.org/updates.html?search_text=macrocyclic+ligand. Also in the Red Book I found nothing. So, does anyone have a source for a definition?

Wulfram G.T. (talk) 19:48, 21 May 2017 (UTC)

If IUPAC doesnt define it, then you'll need to do some work and use your judgement based on a collection of hopefully good books and reviews. If you haveaccess to a high quality technical library and an hour to spare, you can do this readily. If you dont have good library sources, then its Google-and-pray. I googled "macrocyclic ligand book" and found the book "Coordination Chemistry of Macrocyclic Compounds", which appears reasonably authoritative judging from the fact that one contributing author won a Nobel Prize. The book begins with a definition "a cyclic compound with nine or more members (including all hetero atoms) and with three or more donor (ligating) atoms." Examples in Wikipedia include TACN and 9-ane-S3. Not that it matters, but for me, macrocyclic ligands usually refer to tetradentates with ring sizes between 12 and 16. --Smokefoot (talk) 20:17, 21 May 2017 (UTC)

Popular pages report

We – Community Tech – are happy to announce that the Popular pages bot is back up-and-running (after a one year hiatus)! You're receiving this message because your WikiProject or task force is signed up to receive the popular pages report. Every month, Community Tech bot will post at Wikipedia:WikiProject Chemistry/Archive 42/Popular pages with a list of the most-viewed pages over the previous month that are within the scope of WikiProject Chemistry.

We've made some enhancements to the original report. Here's what's new:

  • The pageview data includes both desktop and mobile data.
  • The report will include a link to the pageviews tool for each article, to dig deeper into any surprises or anomalies.
  • The report will include the total pageviews for the entire project (including redirects).

We're grateful to Mr.Z-man for his original Mr.Z-bot, and we wish his bot a happy robot retirement. Just as before, we hope the popular pages reports will aid you in understanding the reach of WikiProject Chemistry, and what articles may be deserving of more attention. If you have any questions or concerns please 0contact us at m:User talk:Community Tech bot.

Warm regards, the Community Tech Team 17:16, 17 May 2017 (UTC)

This tool provides very useful information that helps guide article improvement. Many readers and editors are grateful for these efforts.--Smokefoot (talk) 18:56, 17 May 2017 (UTC)
Should we consider upgrading importance on article with a lot of readers (on a permanent basis)? Graeme Bartlett (talk) 11:13, 18 May 2017 (UTC)
Might be worth looking at the popular articles that are not standard chemistry content for accuracy. For example, number 2 on the list (with approaching 10k views day−1) is BODIPY. Its synthesis image (File:BODIPY synth.png) was uploaded in 2008 by Ph0987, who has only made one edit since 2014 and only four edits since 2012, and the image has an error. The second synthesis should show ArCOX as the reagent to match the aryl group in the product and the text, but for some reason reads RCOX. This article has seen little editing – eight edits in the last four years for these cumulative changes – and I'm not sure where all the traffic came from on 3 and 4 April (~274 000 views) but in general articles getting substantial sustained traffic are likely worth some attention. I'm not convinced that more traffic means more important as a chemistry topic, though. EdChem (talk) 13:41, 18 May 2017 (UTC)
Massive number of views over a couple of days only suggests some automation out of control. But if it sustained viewing it would be more human interest. Graeme Bartlett (talk) 21:17, 19 May 2017 (UTC)

Another round of student additions?

I think I might have found a bunch of new pages created as some sort of student assignment. The properties seem to be as follows:

  • New editors with no userpages who created new articles on 21 April and have edited only those pages
  • Pages added either in one go or in a flurry of edits over a couple of days

At first glance most of these pages seem to be ok but I have to admit I haven't gone through them carefully. However, unless there are just 7 people in this class I'm clearly missing some. --Project Osprey (talk) 14:26, 9 May 2017 (UTC)

Page name Creation date Creator
Organotantalum chemistry 21 April User:Bhuffmanscripps
Nickel(II) precatalysts 21 April User:Samantha.green403
Chemical bonding of H2O 21 April User:Holmescallas
Cobalt(II)–porphyrin catalysis 21 April User:Deadpan07
Mukaiyama hydration 21 April User:Solosh11
Stannatrane 21 April User:J.derosa
Moroidin 25 April User:Momast017

I am very pleased with this find, new content! V8rik (talk) 17:27, 9 May 2017 (UTC)

Yes, we are graduate students and this was an assignment for our organometallics course. Each page was peer-reviewed by two other students in the class. Solosh11 (talk) —Preceding undated comment added 02:49, 10 May 2017 (UTC)

New homework essays by kids with weak perspectives and reliant on primary, mainly US sources, but we can anneal these things over time. Unfortunately, their teachers are probably not very involved. --Smokefoot (talk) 16:12, 10 May 2017 (UTC)
Certainly better contributions than those other recently created stubs. Graeme Bartlett (talk) 10:24, 11 May 2017 (UTC)

And again

Another round of new pages and large expansions Wikipedia:Wiki Ed/Dartmouth College/The Chemistry of Macromolecules (Spring 2017). --Project Osprey (talk) 12:08, 16 May 2017 (UTC)

And still more

Wikipedia:Wiki_Ed/Hunter_College/Chemistry_378_(Spring_2017), taking on gigantic topics. Not very promising. Instructor basically missing in action.--Smokefoot (talk) 14:25, 22 May 2017 (UTC)

Not just gigantic topics but in gigantic numbers... 98 students! (am I reading that correctly?) that must be some kind of record for us. --Project Osprey (talk) 14:43, 22 May 2017 (UTC)
The edits from this course I've encountered on watchlist are virtually all nuke-on-sight bad. It's as if they had no training or resources about the basics of what WP is and how articles and subarticles are structured. DMacks (talk) 19:59, 22 May 2017 (UTC)

Please assess a new draft

See User:BeaglePower/sandbox, I'm not sure what to make of it. It seems to me that it covers several different aspects of acid-base chemistry, but my knowlege of the topic is rudimentary and rusty - high school was over 30 years ago. Roger (Dodger67) (talk) 20:02, 22 May 2017 (UTC)

  • It would be excessive to add this to Russell S. Drago which already has a summary of the topic(s). For this to become an article we really need secondary (review or book) references to show that the concepts are notable. It would go to an article titled ECW model or electrostatic and covalent parameters. Has anyone here ever heard of these concepts before? Graeme Bartlett (talk) 23:38, 22 May 2017 (UTC)
I have moved this to Draft:Electrostatic and Covalent Equation for now. If there is a better title, it can be moved again? Robert McClenon (talk) 02:00, 23 May 2017 (UTC)
The E-C equation is probably notable because Drago was prolific promotor. It was introduced in the spirit of Gutmann's Donor number, a result of the 1950's-1960's fascination with parameterizing (Lewis) acid-base reactions. Drago sought to extend the concept to coordination complexes. A huge fight broke out as this quantitative parameterization competed with Pearson's more qualitative HSAB theory. Gerold Schwarzenbach (der Prof at ETH, popularier of EDTA) was also involved. At least in the US, Drago was influential as indicated by his winning ACS's Inorganic Awd. The E-C equation was basically his life's work. I glanced at the article. It seemed way too long, but almost all articles seem that way to me. My 2 cents. --Smokefoot (talk) 02:17, 23 May 2017 (UTC)
Can it be accepted into mainspace it its current state, or do one of you topic specialists want to do a review? Roger (Dodger67) (talk) 12:07, 23 May 2017 (UTC)
OK, I shrunk it to 40% of the original and named it following Graeme's suggestion. See ECW Model. --Smokefoot (talk) 01:11, 24 May 2017 (UTC)

Also requesting the review of Draft:Kinetic isotope effect measurement at natural abundance, a draft that has been waiting for nearly 30 days. JTP (talk • contribs) 14:54, 25 May 2017 (UTC)

It appears as if the text of this draft has already been merged into Kinetic isotope effect. -- Ed (Edgar181) 15:02, 25 May 2017 (UTC)

Chirally?

Check out [list] for articles using the term "chirally". My guess is that it is not a word. If anyone has suggested alternatives, go for it. --Smokefoot (talk) 03:37, 26 May 2017 (UTC)

If the first page of hits is a representative sample, it's a valid word because it's used in titles of cited refs. "Chirally Correct" also appears to be some sort of marketting mumbo-jumbo for some cosmetics. DMacks (talk) 03:41, 26 May 2017 (UTC)
It's a word. It's the adverb formed from "chiral", which means "lacking mirror symmetry", and is used (in my experience) in chemistry, physics, and mathematics. The phrase "chirally correct" is also useful: for example, amino acids exist in laevo- and dextro- forms, with only the laevo- forms being nutritious, so a protein supplement containing dextro amino acids would be of little value, and "chirally incorrect". Marketing people can of course write any kind of bullshit. Maproom (talk) 07:50, 26 May 2017 (UTC)

Adept (insect growth regulator)

I'm not sure about the notability criteria for chemicals, so I was hoping someone from this Project could scan the article. At first glance, it may be too WP:PROMO thanks to the WP:PRIMARY sources. Nicnote • ask me a question • contributions 20:35, 30 May 2017 (UTC)

This article should be either redirected or merged into the existing article about the active ingredient in Adept, diflubenzuron. We generally don't have separate articles about the many different branded products that contain an insecticidal ingredient unless they are independently notable according to the general notability guideline, which doesn't appear to be the case here. -- Ed (Edgar181) 21:20, 30 May 2017 (UTC)
Agreed. It should be merged into diflubenzuron (not that there is a lot to merge), and redirected. ―Biochemistry🙴❤ 21:42, 30 May 2017 (UTC)
 Already done actioned by Octoberwoodland. Graeme Bartlett (talk) 23:56, 30 May 2017 (UTC)
Added to Adept (disambiguation). ―Biochemistry🙴❤ 15:55, 31 May 2017 (UTC)

AcacH enol is C2v?

Is this figure from acetylacetone correct? I would ask on that talk page but this is an important compound.

--Smokefoot (talk) 01:41, 31 May 2017 (UTC)

A π-bond involving a hydrogen atom? That's an interesting idea. Maproom (talk) 08:35, 31 May 2017 (UTC)
Not a theoretician, but pseudo-aromaticity seems to be a thing and has been invoked for acetylacetonates. [1] No, I don't like the dotted formulas either and prefer to write individual resonance structures. The latest on the hydrogen bond in acetylacetone is that it seems to be symmetric, [2] but I don't know how conclusive the interpretation is. 158.93.6.11 (talk) 14:54, 31 May 2017 (UTC)
The diagram does not look to me like a π bond to H, since it's not contiguous with the curve curve of delocalized π that runs O–C–C–C–O. But this diagram is in keeping with that ref, which is also cited in the Acetylacetone article. DMacks (talk) 04:09, 1 June 2017 (UTC)

Transporter Classification Database

The Transporter Classification Database is an important source for information about transporter proteins, and it is labeled as CC-BY. But in fact this database often copies content from copyrighted journal articles (likely in good faith, because the people who wrote the database entries also wrote the copyrighted journal articles--but a problem nonetheless). Just wanted to get the word out so that we don't accidentally import copyright violations from this source. See Wikipedia:Contributor copyright investigations/Transporter Guy for more information. Calliopejen1 (talk) 21:01, 6 June 2017 (UTC)

Jamal Lasri

I have issues with Lasri condensation which I suspect may eventually require an admin - I don't really have enough evidence to start anything yet and I don't want to get in trouble because of that, so I'm just going to explain things here in the hopes of getting some advice. The Lasri condensation is named in honour of Jamal Lasri, which is impressive as the paper detailing the reaction only came out this year (there's no DOI and I cannot find it at all online), so there's obvious issues of WP:UNDUE there. That makes me suspicious of the people editing the page (new editors who aren't editing anything else). However while digging I also found Draft:Jamal Lasri which seems to have become marooned because of Wikipedia:Sockpuppet investigations/Jamal.lasri/Archive which kind of implies that there's someone more serious going on here. --Project Osprey (talk) 21:27, 1 June 2017 (UTC)

I CSD#G5ed the draft and blocked the editor who has written it as part of that sock-drawer. DMacks (talk) 05:22, 2 June 2017 (UTC)
Many thanks, I tried PRODing Lasri condensation but was overturned by the page editors (unsurprisingly). I'm not sure it meets the criteria for a speedy deletion so I'm to take it to AfD unless you have any objections? --Project Osprey (talk) 08:09, 2 June 2017 (UTC)
No objections. That will help bring extra eyes, especially since it involves long-term site abuse. DMacks (talk) 12:12, 2 June 2017 (UTC)

I have added some of the material from the Lasri condensation page to other articles, and on further checking realised that the well-known formation of 3,5-diphenyl-1H-pyrazole involves the reaction of chalcone with hydrazine hydrate, either in the presence of sulfur (2008 ref: doi:10.1002/jhet.5570450231) or sodium persulfate (2014 ref: doi:10.3987/COM-13-12867). What seems to be being claimed as the "Lasri condensation" involves using a hydrazone instead of the hydrazine + sulfur oxidant. I can find no references to a Lasri condensation nor web-links that don't track back to WP. My motivation in adding content to pyrazole, chalcone, azine, and hydrazone was so that the non-notable Lasri condensation page could be AfD'd with a rationale that relevant content is already in appropriate / potential articles and the claim of a named reaction is unsupported by sources and non-notable. I realise that my additions may be removed / trimmed as undue, which is fine.

I note particularly that DMacks has reverted me at chalcone and then added a comment on the generalisability of the approach to 3,5-disubstituted 1H-pyrazoles, which is undoubtedly true. The problem I have with the revert is it leaves two references neither of which refers to a hydrazone supporting a scheme using a hydrazone, but the only reference available is an "in press" article, which I admit is problematic. I am going to reinstate my edit to make the text accurate, but also seek input here on what we should do:

  1. Should we rename File:Scheme1jpg.jpg and File:Scheme1jpg.jpg from the Lasri article to something more appropriate? (I have used the first several times, but not the second).
  2. Alternatively, should we re-draw File:Scheme1jpg.jpg to use hydrazine hydrate and then ditch all mention of the in press article?
  3. Is there anything from the mechanistic description in the Lasri article worth using elsewhere? It includes reference to doi:10.1016/j.molstruc.2016.05.044 with the structure of the azine from fluorenone, FYI.
  4. Should we go ahead and AfD the Lasri condensation article?
  5. Is Lasri notable? I see that Jamal Lasri is salted after apparently five deletions (most recently in 2015) though there is an es:Jamal Lasri article, which provides links to ar:Jamal Lasri, it:Jamal Lasri, sh:Jamal Lasri, and az:Camal Lasri.

All input / thoughts welcome.  :) EdChem (talk) 08:27, 12 June 2017 (UTC)

Take it to AfD first, if its gets deleted then the images will likely need to be deleted too. I don't think he meets WP:PROF. I had meant to do this myself but real-life has caught up with me so I'm not editing much at the moment. --Project Osprey (talk) 10:07, 12 June 2017 (UTC)

Synonym Check

While we are on the subject (above) are there any super dooper chemists who could doublecheck whether an synonymous article does infact exist for any of the chemicals (contained within tobacco smoke) below?

Bosley John Bosley (talk) 16:05, 11 June 2017 (UTC)

n-Propylbenzene does not but it has several mentions in other articles and should probably be created to resolve its redlink on Propylbenzene. DMacks (talk) 20:42, 11 June 2017 (UTC)
Stubbed. Please contribute (de.wp and others have an article with some sourced content already). DMacks (talk) 04:13, 12 June 2017 (UTC)
I added CAS#s to the above list. It's a pretty good way to search for articles on WP, and likewise key info to include in an article and for pubmed and other lit searches. I couldn't find * 2-Amino-3-methylimidazo(4,5-b)quinolone in pubmed, but I did find 2-Amino-3-methylimidazo(4,5-f)quinoline (CAS# 76180-96-6) that lists "IQ" as a synonym. DMacks (talk) 21:38, 11 June 2017 (UTC)
Structural searching doesn't find any matches either. On the face of it I would have though that the nitroso compounds (which are all based on simple compounds that we already have pages on) would make valid pages of their own. I'm not so sure about the others, they're all fairly niche poly-aromatics, I doubt we'd even be able to find boiling points for them. --Project Osprey (talk) 10:38, 12 June 2017 (UTC)
Thanks guys, I suspect (subject to my near zero competence) that some such as N-nitrosodiethanolamine maybe the tobacco-specific chemicals found only in tobacco products mentioned above. If (and only if) I find WP:RS refs I plan to create/merge them into that article (estimated timescale = months). If this is not a good idea ...speak now...Bosley John Bosley (talk) 13:53, 13 June 2017 (UTC)
I'd be glad to help on the chemistry if you develop an article that describes (even lists) these components. The aspect that I was objecting to was the mention of tobacco-relatedness in the individual chemical articles for reasons stated above. BTW, those entries will eventually be removed in view of the consensus above, again time scale of days or weeks.--Smokefoot (talk) 14:07, 13 June 2017 (UTC)

Facto Post – Issue 1 – 14 June 2017

Facto Post – Issue 1 – 14 June 2017
Editorial

This newsletter starts with the motto "common endeavour for 21st century content". To unpack that slogan somewhat, we are particularly interested in the new, post-Wikidata collection of techniques that are flourishing under the Wikimedia collaborative umbrella. To linked data, SPARQL queries and WikiCite, add gamified participation, text mining and new holding areas, with bots, tech and humans working harmoniously.

Scientists, librarians and Wikimedians are coming together and providing a more unified view of an emerging area. Further integration of both its community and its technical aspects can be anticipated.

While Wikipedia will remain the discursive heart of Wikimedia, data-rich and semantic content will support it. We'll aim to be both broad and selective in our coverage. This publication Facto Post (the very opposite of retroactive) and call to action are brought to you monthly by ContentMine.

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Draft:Generation of Carbocationic Synthons

Will someone please review Draft:Generation of Carbocationic Synthons? Please be aware that the author never responds to anyone. She just submits stuff. If it is a useful topic but needs work, someone else has to do the work. She just throws things over the transom. I can see that it would benefit from the addition of links to related topics to facilitate understanding and assessment. Is it worth working on? Robert McClenon (talk) 00:28, 14 June 2017 (UTC)

I have knocked it back as Carbocationic synthon already exists. Graeme Bartlett (talk) 11:08, 14 June 2017 (UTC)
That article does not define "Carbocationic synthon" that I could find. Nor could I find a citation to a secondary source with "Carbocationic synthon" in the title. Oh well, its only Wikipedia. --Smokefoot (talk) 13:12, 14 June 2017 (UTC)
There is not even a primary source that has that in the title, only a passing mention. So its is certainly not notable. I have changed to a redirect to Synthon. Graeme Bartlett (talk) 01:39, 15 June 2017 (UTC)
Thank you. This is a very strange editor who submits reasonably good technical stuff to AFC but never pays any attention to the responses. Sometimes her submissions are accepted, and she resubmits them a month or two months later anyway, and they have to be declined as already existing. We assume that there is a human behind the user name, but they don't pass the Turing test, because they don't either seem to be trying to act like a human or trying to act like a bot. Robert McClenon (talk) 22:38, 15 June 2017 (UTC)

Review request from EPR expert

Hi, please could an EPR expert review the section "Hardware components" on the EPR article. I endeavored to make it as accurate as possible but I am no expert on EPR hardware. kind regards EvilxFish (talk) 15:22, 3 July 2017 (UTC)

Oxyanion

Definition of oxyanion is the following:

"An oxyanion or oxoanion is an ion with the generic formula A
xOz−
y (where A represents a chemical element and O represents an oxygen atom)."

Acording to this definition hydrogen oxyanions like hydrogen sulfate not part of the class oxyanion. Is it correct to limit so strictly the definition of oxyanion ? Thanks for your comment. Snipre (talk) 19:24, 5 July 2017 (UTC)

Change disambiguation page to normal article

Metasilicate is currently a disambiguation page but this is not correct: metasilicate is the name of a chemical compounds class like Silicate. So we have to be coherent and change Metasilicate in a normal article or change Silicate into a disambiguation page. Can someone indicate me what is the correct procedure to transform Metasilicate into a normal page ? Thank Snipre (talk) 09:09, 10 July 2017 (UTC)

I would suggest that you just go and edit it to be a normal article. User:Congruence created it more than 10 years ago, but has not edited for over a year, so probably will not mind a change. I would support the idea of converting it to an article on the chemical class. I do not suggest that you change silicate to a disambig page: it is better as it stands. Graeme Bartlett (talk) 13:00, 10 July 2017 (UTC)
I agree with Graeme, just go ahead and write the article. To maintain the prior function of the disambiguation page, you can perhaps keep the links to sodium metasilicate and calcium metasilicate within the new article as listed examples of metasilicates. ChemNerd (talk) 13:50, 10 July 2017 (UTC)

Niche categories for chemicals

I have noticed a couple of new categories for chemicals that appear to be uselessly narrow. They were all created by an editor, حسن علي البط (talk · contribs · deleted contribs · logs · filter log · block user · block log), who has been warned and even blocked for creating pointless chemical categories in the past. I just wanted to bring these to the attention of chemists here to decide what to do.

Are these useful in any way? ChemNerd (talk) 13:31, 28 June 2017 (UTC)

@DMacks: Pinging DMacks, because you were the blocking admin. ChemNerd (talk) 13:31, 28 June 2017 (UTC)
Cat:Picolinic acids has more than one entry, so perhaps is useful. The others only ahve one entry each, and so unless other things are added are not useful. Graeme Bartlett (talk) 02:34, 29 June 2017 (UTC)
It might also be appropriate to add chromium(III) picolinate and dipicolinic acid, and what about isomers like nicotinic acid? Perhaps broaden from picolinic acid to cover all pyridinecarboxylic acids? EdChem (talk) 03:24, 29 June 2017 (UTC)
Picolinic acids might be a useful category (see w:commons:category:picolinic acids), but the others seem too narrow to be useful. -- Ed (Edgar181) 18:42, 7 July 2017 (UTC)
It does to me. Sodium salts are compounds containing sodium, if that doesn't make them sodium compounds, I don't know what does. OrganoMetallurgy (talk) 22:30, 30 June 2017 (UTC)
Technically correct, it puts so many in the category, that we should have subcategories such as category:organic sodium salts. Graeme Bartlett (talk) 22:36, 30 June 2017 (UTC)
I'll probably make a subcategory like that once I figure out if there is any difference between salts and ionic compounds. OrganoMetallurgy (talk) 22:45, 30 June 2017 (UTC)

First, I apologize for not participating in dialouge about categorization before, I believe that we should make thw category even it contain only one member, later we will find members to be added, but recently I think we should add about twice the existing categories to helo build the main skeleton. حسن علي البط 02:59, 3 July 2017 (UTC)

I wish you had waited for a response before creating the two benzoquinone subcategories. They are unnecessary and probably even unhelpful. Once categorization becomes so narrow that there are only a few pages in the category, categorization can no longer adequately serve its purpose. Right now Category:1,2-Benzoquinones only includes 1,2-Benzoquinone. -- Ed (Edgar181) 18:42, 7 July 2017 (UTC)
yes Category:1,2-Benzoquinones contain only its main article, but on the other hand Category:1,4-Benzoquinones contain more than 30 articles. حسن علي البط 05:02, 11 July 2017 (UTC)
  • Impotant, the page 2- and 4-Quinolones must be separated in 2 different pages, the first is lactam while the other is ketone and they are completely different. حسن علي البط 05:02, 11 July 2017 (UTC)

Lack of a page about extrusion reactions

Could someone create a page on extrusion reactions? It stuck me as odd that there isn't one already. I'd make one myself, but it'd probably end up having to be completely rewritten and I'm busy working on creating other pages. OrganoMetallurgy (talk) 01:30, 6 July 2017 (UTC)

Never heard of "extrusion reactions", maybe an example would spur some action or kick start our memories. The early organic editors here were pretty thorough on the classics.--Smokefoot (talk) 13:12, 6 July 2017 (UTC)
Is Reactive extrusion the same thing? Bosley John Bosley (talk) 15:25, 6 July 2017 (UTC)
Reactive extrusion is not the same thing at all. Extrusion reactions are the opposite of insertion reactions. they are of the form X-Y-Z -> X-Z + Y. OrganoMetallurgy (talk) 16:32, 6 July 2017 (UTC)
I suppose the Hooker reaction is an example. As are some ring contractions. OrganoMetallurgy (talk) 16:58, 6 July 2017 (UTC)
I expect such reactions are few and far between. Kishner cyclopropane synthesis might be one if you allow for Y to be more than 1 atom. --Project Osprey (talk) 23:08, 6 July 2017 (UTC)
That's what I was thinking. Unless one considers retro-Diels-Alder processes like dihydrothiophene dioxide to SO2 + diene.--Smokefoot (talk) 23:16, 6 July 2017 (UTC)
I'm not a very good person to ask about the topic, but I can tell you that while the exact phrase "extrusion reaction(s)" might not be used very frequently, it's hardly an uncommon type of reaction.OrganoMetallurgy (talk) 21:12, 13 July 2017 (UTC)
Could you perhaps mean reductive elimination? --Project Osprey (talk) 22:38, 13 July 2017 (UTC)
No, although I suppose it technically qualifies as an extrusion reaction in the broader sense. According to "Synthetically useful extrusion reactions of organic sulfur, selenium and tellurium compounds" https://doi.org/10.1016/S0040-4020(01)89815-X, the term extrusion reaction is typically applied to ring contractions where a bridging small inorganic molecule such as N2, CO2, or SO2 is lost, but also more broadly refers to any reaction wherein a bridging atom or molecular fragment is lost and a bond is formed between the atoms that were attached to the bridge, and term is also sometimes applied to retro-Diel-Alder reactions involving the loss of a small inorganic molecule. A better example of a extrusion reaction is the Ramberg–Bäcklund reaction. OrganoMetallurgy (talk) 23:11, 13 July 2017 (UTC)
Even if they are rare, I'd still say they should have a page written about them. Are you interested in writing one? OrganoMetallurgy (talk) 00:05, 14 July 2017 (UTC)
  • Well you've already found a review ref and I normally consider that to be the threshold for notability. There looks to be common a theme with all of these reactions; depotonation of an acidic carbon leading to intramolecular attack, accompanied by oxidation of C or S into a leaving group. It's weird stuff. --Project Osprey (talk) 10:21, 14 July 2017 (UTC)
Agreed. If compound or a reaction cannot be supported by a review or a book, its notability is questionable. Its not a black-white thing. Another threshold might be numbers of hits in CAS, for those that have access to that database. --Smokefoot (talk) 14:39, 16 July 2017 (UTC)

Going back to the subject of the creation of a page on extrusion reactions, you're welcome to ask me any questions regarding the subject here, on my talk page, or the talk page of the article once it is started. OrganoMetallurgy (talk) 00:12, 17 July 2017 (UTC)

I have uploaded an image that might be useful for such a page, showing the loss of CO to form pentacene, here: File:Formation of pentacene by extrusion of CO.jpg. EdChem (talk) 11:30, 19 July 2017 (UTC)
It seems to follow the general pattern of "ring closure followed by retro-cycloaddition". If there is a ChemRev about that specific combination or two-stage process (or maybe there are other general processes?), then I agree an article covering the unified aspects is reasonable. We'd have to be careful to avoid focusing substantially on the retro-cycloaddition itself, since that is a more general topic rather than a well-contained subtopic. Or, since retro-cycloaddition is currently only a redirtect to cycloaddition, maybe we should instead convert that into its own article, which could then have a subtopic for extrusion reactions. DMacks (talk) 13:59, 19 July 2017 (UTC)
The Tsuji-Wilkinson decarbonylation reaction is an extrusion that does not involve retro-cycloaddition. EdChem (talk) 19:53, 19 July 2017 (UTC)
Neat reaction I didn't know! The key step is a migratory extrusion (redlink), reverse of a migratory insertion. So now we have two types of "extrusion" with different mechanisms, so at least (and even if the union of these two don't make one notable topic) we need a parent article to collect the common ideas and link out to the reactions that involve each one. DMacks (talk) 20:57, 19 July 2017 (UTC)
Are we allowing metal catalysed reactions? To my eyes at least (and I'd be grateful if someone could voice an option on this) the mechanism of all the organic reactions could be considered exotic versions of E1cB-elimination --Project Osprey (talk) 22:08, 19 July 2017 (UTC)
There are plenty of biochemical decarboxylations, like meso-2,6-diaminoheptanedioate to L-lysine by the enzyme diaminopimelate decarboxylase. Bacteria then decarboxylate lysine to cadaverine. There is also the radical Barton decarboxylation in the laboratory. In the Hooker reaction, a methylene is oxidised and the overall effect is extrusion as carbon dioxide. The Carroll rearrangement involves extrusion of carbon dioxide as the overall process. Azo compounds like AIBN decompose by loss of nitrogen gas. For AIBN, this not an extrusion as the product is two stable radicals, though if they recombined the overall process would be N2 extrusion. I've seen mention of benzoic acid conversion to benzene with ascorbic acid or quinolone. EdChem (talk) 07:08, 20 July 2017 (UTC)


Reaction name Starting material Product type driving force of X-Z bond formation driving force at extrusion step extruded chemical Comments
Ramberg–Bäcklund reaction linear sulfone linear alkene carbanion ring strain? SO2
Hooker reaction linear alkane (by a naphthoquinone) linear alkane carbanion decarboxylation CO2
Tsuji-Wilkinson decarbonylation reaction various linear carbonyls various, linear reductive elimination decarbonylation CO
Eschenmoser sulfide contraction linear thioester linear 1,3-dicarbonyl compounds intramolecular conjugate addition elimination reaction (E1cB?) triphenylphosphine sulfide
Example Example Example Example Example Example Example

Constituent of tobacco smoke

I recommend that we remove notes in chemical articles of the following type: "Carbon disulphide is a constituent of tobacco smoke.<ref name="TalhoutSchulz2011">{{cite journal|last1=Talhout|first1=Reinskje|last2=Schulz|first2=Thomas|last3=Florek|first3=Ewa|last4=Van Benthem|first4=Jan|last5=Wester|first5=Piet|last6=Opperhuizen|first6=Antoon|title=Hazardous Compounds in Tobacco Smoke|journal=International Journal of Environmental Research and Public Health|volume=8|issue=12|year=2011|pages=613–628|issn=1660-4601|doi=10.3390/ijerph8020613|pmid=21556207|pmc=3084482}}</ref>". No doubt that these additions are well intentioned, but that is sufficient criterion for inclusion.

My argument: One could list thousands of things that contain H2S (and other common chemicals), but we are not a in the listing business. The same editor User:Bosley John Bosley also adds the category of Category:Constituents of tobacco smoke, which would appear to achieve the same goal.--Smokefoot (talk) 13:10, 11 June 2017 (UTC)

H2S and Carbon disulphide have significant Health effects - which are we talking about? Bosley John Bosley (talk) 15:34, 11 June 2017 (UTC)
I agree with you in this instance. I was thinking the category was unsuitable. The constituents can be listed in the tobacco smoke article, and only highly significant substances need to mention tobacco (eg nicotine, tar, carbon monoxide). Another unsuitable category: Category:chloride, when we have Category:chlorides. Graeme Bartlett (talk) 13:16, 11 June 2017 (UTC)
Smokefoot above states that we are not in the listing business - how can you both agree with him and state that the constituents can be listed in the tobacco smoke article? I started the category because the list was simply too unwieldy. If there is an issue with [[category:Constituents of tobacco smoke]] then this should be raised at WP:CFD - unlike Category:chlorides the subject matter has a wider circle of stakeholders than wikipedians from WikiProject Chemistry - is tar even a chemical? Bosley John Bosley (talk) 15:34, 11 June 2017 (UTC)
I agree as well, one could continue this till the absurd .. 'water is a constituent of sea water, tap water and rain water'; 'CO2 is a constituent of air, tobacco smoke, car exhaust gasses' .. The constituents can be listed in the article of the mixture, not on the articles of the individual constituents. --Dirk Beetstra T C 13:20, 11 June 2017 (UTC)
A preschool kid knows that sea water, tap water and rain water contains water. I doubt even an oncologist could list at least 73 known carcinogens in cigarette smoke <ref>[[Lung Cancer]]</ref> Absolutely every category in Wikipedia could instead have been be listed in an article...However, some bright spark came up with the idea of categorisation. Bosley John Bosley (talk) 15:34, 11 June 2017 (UTC)
@Bosley John Bosley: Categorisation is one thing, but adding this on each article is IMHO too much. And also for the categorisation, it is impossible to do that consistently. Again, water is a constituent of a lot of things, so the ad absurdum reduction of the argument for carbon disulfide would result in many categories on some compounds. And you can do that already for stuff like carbon disulfide - I am sure that you can find it in crude oil, and, knowing its properties, probably even still in the petrol you put in your car). That then goes to the next ad absurdum reduction - many chemical compounds can be found as trace compounds in many places (giving arguments to homeopathy to put categorise them there?). I can't fathom the amount of problems this gives. I think that this should be done with due care. --Dirk Beetstra T C 08:25, 12 June 2017 (UTC)
I also agree.JSR (talk) 14:48, 11 June 2017 (UTC)
I also disagree with you Bosley John Bosley (talk) 15:34, 11 June 2017 (UTC)
John Bosley, I am convinced that you are acting with good intentions, even if it appears that consensus is against adding your commentary to so many articles (sort of a spamming exercise, which is usually a bad thing here). My guess is that you are underestimating two things that the other commenting editors are more experienced with: (i) the chemical complexity of our world and (ii) the commitment of editors to keep articles from turning into lists of factoids. Maintaining a disciplined article is a constant battle because the entire physical universe is a jumble of chemicals, and many some editors are intent to remind readers of the stuff used to kill ants, fuel model airplanes, or found as a component of something. --Smokefoot (talk) 16:19, 11 June 2017 (UTC)
Spamming is an issue for WP:ANI. I believe the commitment of editors more experienced with the chemical complexity of our world might be more productively demonstrated with the help on the list below. Factoids are trivial or unreliable information that is reported and repeated so often that it becomes accepted as fact. That is not the case here. Bosley John Bosley (talk)
We also have Tobacco-specific nitrosamines about a certain subcategory of these chemicals. DMacks (talk) 21:20, 11 June 2017 (UTC)

On a related note, Tobacco smoke already has a list of tumorigenic agents (which it tries to organise by class - an idea I like). This list is longer than the one at List of cigarette smoke carcinogens, so there's an obvious question about merging that fork back in, however the sourcing of the list in unclear with no obvious references. --Project Osprey (talk) 10:46, 12 June 2017 (UTC)

Component of tobacco smoke is back on the table

@Bosley John Bosley: OK, I thought that we had reached consensus, and I had started to remove the ref and the categories from many of chemical articles. You can check out my activity. Apparently User:Bosley John Bosley is not satisfied as indicated here. So maybe he would want to argue the case again. The argument for removal of most of the mentions of various chemicals being in tobacco smoke boils down to, IMHO, WP:UNDUE. There are myriad chemicals in many things in everyday life, and many chemicals are pervasive.

It would be good idea to achieve some resolution on this issue perhaps for our MOS, because this kind of thing is going to come up again as other similarly well intended editors who are less familiar with the intensely chemical nature of our existence. --Smokefoot (talk) 17:28, 19 July 2017 (UTC)

Well, for instance I have reverted this edit as I simply do not see where you feel the consensus is with you. Incidentally I was thanked for this edit by @Parcly Taxel:. Also the correct forum for the removal of the category:Constituents of tobacco smoke is WP:CFD...( I doubt many oncologists & other health professionals, ex smokers, current smokers, wikipedians working in the tobacco industry, vapers and conspiracy theorists have Wikipedia talk:WikiProject Chemistry on their watchlist) I suspect Category:Constituents of ant poisons, and Category:Constituents of model airplane fuel would not pass muster at WP:CFD, but I am convinced Category:Constituents of tobacco smoke would remain. Bosley John Bosley (talk) 00:43, 20 July 2017 (UTC)
I think the issue is more WP:NOTABILITY. The fact that a compound can be found in tobacco smoke doesn't seem notable enough for inclusion in the article about the compound. OrganoMetallurgy (talk) 03:02, 20 July 2017 (UTC)
@OrganoMetallurgy: The fact that Triethylamine can be found in FlyNap remains; The fact that Triethylamine can be found in Tobacco smoke does not, The only difference between the two is that the Tobacco Smoke fact is more notable and was supported by a WP:RS; The Flynap is unreferenced. Can this bizarre approach be supported by WP:NOTABILITY? Bosley John Bosley (talk) 03:21, 20 July 2017 (UTC)
@Bosley John Bosley: At what concentration do you propose notability kicks in? Who makes that decision if it is variable - you?--Smokefoot (talk) 13:36, 20 July 2017 (UTC)
On Wikipedia, notability is a test used by editors to decide whether a given topic warrants its own article. Bosley John Bosley (talk) 13:44, 20 July 2017 (UTC)
@Bosley John Bosley: Let me rephrase, at what threshold concentration of a compound in tobacco smoke does the mention of it occurrence merit mention with a reference and category.?--Smokefoot (talk) 13:58, 20 July 2017 (UTC)
The threshold concentration that I used to start the category were the 73 odd chemicals listed in Hazardous Compounds in Tobacco Smoke. Ironically this enabled me to discover afterwards that, despite repeated scaremongering of these nasties being in tobacco smoke, many of these chemicals (for instance Mercury) do not actually contribute to the dangers of smoking. Those facts remain relevant reliable and sufficient for inclusion in the article. Bosley John Bosley (talk) 14:23, 20 July 2017 (UTC)
@Bosley John Bosley: Oops, I meant WP:NOTEVERYTHING. OrganoMetallurgy (talk) 15:08, 20 July 2017 (UTC)
Ok, bearing down on cancer. The paper gives a 'Cancer risk value' for 60 compounds, most of those aren't confirmed human carcinogens so how that's been done is beyond me but I'm guessing lots of statistics. So far I've only been able to pick out 5 IARC Group 1 carcinogens (they're not highlighted in the article so there may be more): Vinyl chloride, Trichloroethylene, Polonium-210, Benzene, Acetaldehyde. Perhaps we could start there? --Project Osprey (talk) 15:12, 20 July 2017 (UTC)
Personally, as a category, it doesn't make sense per WP:NONDEFINING. Water's a tobacco smoke component. So what. But as a list? I'd absolutely support that. Headbomb {t · c · p · b} 15:54, 20 July 2017 (UTC)
@Project Osprey: the issues you mention are precisely why I started this "sub-project" in the first place - there are some real nasties backed up by science but also a lot of scaremongering gumph out there and Wikipedia's coverage of the subject is anything but encyclopaedic.@Headbomb: Per WP:ND reliable sources do commonly and consistently define in prose these chemicals as constituents. I created the category precisely because the existing list was just too unwieldy - incomplete, and being in tabular form difficult to update and not as user friendly as a categorisation. Bosley John Bosley (talk) 17:40, 20 July 2017 (UTC)
WP:NONDEFINING means that hierarchy wise, tobacco smoke does not define or impart knowledge about what water is, unlike hadron which does define and impart knowledge about what mesons are. Yes benzene is a component of tobacco smoke, but so is water. Yes benzene is harmful, but so is water. Yes acetaldehyde is a component of tobbaco smoke, but it is also a component of bread and fruits. That's why we don't have any [[:Category:Constituents of <insert substance>]] categories, nor should we have them. These components are not notable because they are part of tobacco smoke, nor do they make you think "tobacco smoke" when you hear of them (I know I don't think of tobacco smoke when I hear the word benzene, even if I know benzene is present in tobacco smoke). Headbomb {t · c · p · b} 18:00, 20 July 2017 (UTC)
Instead of water which has never been categorised this way by anyone, rerun that reasoning with Nicotine, Tobacco-specific nitrosamines, 2-Naphthylamine, N-Nitrosodimethylamine N-Nitrosonornicotine. How do you know acetaldehyde is a component of tobacco smoke?...because you read it on Wikipedia?...and yet that snippet of information is being systematically removed...from each article....jeez... Bosley John Bosley (talk)

It seems to me that we have an WP:UNDUE issue here, so I'd like to explore with an example divorced from cigarettes. Let's consider methane, a commonly-occurring substance. Where is the line on what fits into the article?

  • that methane is a greenhouse gas
  • that it is the major component of natural gas
  • that domestic supplies are spike with mercaptans to make it easily detectable by smell
  • the specific mercaptans used
  • the mechanisms by which they are detected in the nose
  • detection limits for olfactory detection
  • nervous system functioning that transmits detection messages
  • that methane is produced as a product of anaerobic respiration
  • that it is consequently a component of human flatus
  • that it is consequently a component of flatus of vertebrates
  • that ruminants produce methane in exhalations
  • comparison of relative methane composition of different ruminants
  • analysis of ruminant contribution to global methane release
  • methane as a feedstock source of nitrogen gas for the Haber process
  • formation of methane clathrates
  • methane clathrate distribution across the solar system
  • viability of methane clathrate as a fuel for interplanterary exploration, and comparison to other potential fuels outside of Earth
  • methane as a fuel
  • mechanism of combustion
  • comparison of mechanism of combustion and atmospheric degradation
  • effect of pollutants (NOx, for example) on the atmospheric degradation

I could keep going, but my point is that all of these are relevant to a discussion of methane at some level, but some would also be excluded from a reasonably-sized general article on methane. Equally, there are many compounds that are present in typical cigarette smoke, a list that will expand if forms (pipe v. cigarette v. e-cigarette), cultivation, plant source (expand to cannabis, etc?) are considered. In an article on "components of smoke from smoking", the question of what is WP:DUE for inclusion is different from articles on those components. Where there is substantial information about the health consequence of a compound (take, say (+)-Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide), including that in the article on the compound is justified. Where there is little to say, or that the health effects of the compound have little if anything to do with smoking (like acetaldehyde), there is much more justification for including it on a "List of components of cigarette smoke" article than for discussing smoking in the acetaldehyde article.

It is the same with homeopathy, including some mention (and link) on a page about homeopathic preparations about potassium dichromate is arguable based on sources. Including material about homeopathy on the KMnO4 page would need some very strong sourcing to justify it.

Taking my methane example, some topics I mentioned I view as core to coverage on the methane page, some could be mentioned with a link to a more appropriate article, and some are UNDUE to mention at all. Stating that water is a component of cigarette smoke on the water article is UNDUE because there is so much to cover that is more relevant. Including a link to an (I hope, theoretical) article List of foods containing sugars on pages like sucrose, glucose, fructose, lactose, ... would all be UNDUE. In considering which chemical articles might appropriately include a mention that it can be found in cigarette smoke, the issue is whether it is supported by references AND is justified by the risk. Noting that a carcinogen is present in absolutely minute amounts still implies it is a cause of smoking-related cancers, and given our detection abilities, taking "carcinogen present" as "relevant for carcinogenicity of tobacco smoking" is not a justified assumption – and including this in the compound's article could be taken to imply just that. EdChem (talk) 06:01, 21 July 2017 (UTC)

Is it not ironic that you chose Acetaldehyde Where there is little to say, or that the health effects of the compound have little if anything to do with smoking According to Wikipedia Acetaldehyde is also the most abundant carcinogen in tobacco smoke....but that does not negate the valid point that you make. I accept it is a matter of degree...I believe my original categorisation reached 73 chemicals - all with "stated" health effects (although a little wiki work later it was clear some of these were exaggerated). The figures touted for the no. of chemicals in tobacco smoke is 4000-6000. The space given to those 73/6000 is not undue. The correct analogy for foods containing sugars is products containing acetaldehyde (which no one is proposing). Sugars are contained in (nearly) all foods just like water is contained in (nearly) all consumer products...it is not correct to argue that the ridiculousness of such categories negates a category such as products containing asbestos where real meaningful information, with real world applications, could be imparted to the reader. Please everyone note when using analogies that, what we are discussing here is also much discussed in the real world and in mainstream media just like [[Category:Hazardous air pollutants]] or greenhouse gases...(there is of course a category for the constituents of greenhouse gas) Bosley John Bosley (talk) 07:42, 21 July 2017 (UTC)
Re Noting that a carcinogen is present in absolutely minute amounts still implies it is a cause of smoking-related cancers, and given our detection abilities, taking "carcinogen present" as "relevant for carcinogenicity of tobacco smoking" is not a justified assumption. From the amateur research I have done for my "sub-project" I believe this statement is absolutely wrong...can we get some input from Project:Medicine? Bosley John Bosley (talk) 07:58, 21 July 2017 (UTC)
I will do a search in the next few days to find articles that list traces of chemicals in coffee, milk, bacon, or some other commonly consumed items. Then we can discuss whether these analytical results should result in new categories. --Smokefoot (talk) 12:52, 21 July 2017 (UTC)
Is there anyone other than BJB that supports these category? Because I feel we're arguing 30 vs 1 here. If that's the case, consensus is against those category and it should be CFD'd. Headbomb {t · c · p · b} 13:01, 21 July 2017 (UTC)
...er...I kinda think you should read WP:Consensus and strike that comment. I suggested WP:CFD Here Bosley John Bosley (talk) 13:34, 21 July 2017 (UTC)
I tried to CFD this category but may have botched some parts of the process. Please take a look and lend a hand. Wikipedia:Categories_for_discussion/Log/2017_July_21.--Smokefoot (talk) 13:41, 21 July 2017 (UTC)
I have left a note at WP:ANI Bosley John Bosley (talk) 13:51, 21 July 2017 (UTC)
Colleagues are encouraged to participate in the discussion of this category at Wikipedia:Categories for discussion/Log/2017 July 21#Category:Constituents of tobacco smoke.--Smokefoot (talk) 12:24, 22 July 2017 (UTC)

Red Links

I have added Amyl Formate (from List of additives in cigarettes) to Formate#Examples. I have added it unlinked. My preference would be to add it red linked (this allows me convenient access to the "What links here" function) . Does there exist an agreed convention? Bosley John Bosley (talk) 07:35, 23 July 2017 (UTC)

I see no reason to avoid adding red links if a compound has some reasonable chance of having enough content for an article. Before doing so, however, and if you are not sure it is likely to be the basis for an article, I would:
  • Do a google search and look for a PubChem page, like this one that gives other potential names under which the page might exist, like pentyl formate or pentyl methanoate or n-pentyl formate.
  • Note that the substance has a CAS Registry Number, in this case, 638-49-3. It is worth doing a search on WP to see if this appears, it may point you to other relevant information if you are considering starting the page. It is also helpful to provide this with your red link, as ([[CAS Registry Number|CAS #]] {{CAS|638-49-3}}) which will produce (CAS # 638-49-3 ), to leave to help anyone looking to expand from your red link later.
  • The PubChem also gives the molecular formula as C
    6    H
    12    O
    2    , so it is worth looking at the WP page C6H12O2 to see if it points you to another name. If you do create a page, adding it to the formula page is helpful.
  • The google search turns up a ChemSpider page with more basic data, and suggests its use as a food additive, which a google book search confirms ([3] [4] [5])
  • A google scholar search also points to some useful information, including its occurrence in a process to remove toluene as a byproduct, along with ethyl formate, and in this review of apples: doi:10.1080/10408398309527367
Short version... I think a red link to amyl formate is perfectly reasonable, but before adding a red link to a compound, if you aren't sure, check for an existing page under a different name and for sufficient information to justify believing the compound is justified in having a page by available information and suitable sources. EdChem (talk) 10:41, 23 July 2017 (UTC)

A new draft needs help

Please see Wikipedia:WikiProject Articles for creation/Help desk#14:58:03, 25 July 2017 review of submission by BeaglePower where the author of Draft:A Visual, Graphical Comparison of Acid and Base Strengths is asking for assistance. Roger (Dodger67) (talk) 16:18, 25 July 2017 (UTC)

Category:Alkenes and other categories with both a broad and a narrow definition.

For example the category Alkenes contains compounds that are not hydrocarbons, which is fine under a more broad definition of alkenes, but isn't under a narrower one. Since much of my editing consists of categorization of articles about chemical compounds, I would like to see if a consensus can be reached concerning what belongs in these types of categories. OrganoMetallurgy (talk) 01:11, 23 June 2017 (UTC)

I think that what is in this category should be the same as that the alkene article says it is, so it should only include compounds with only carbon and hydrogen. We need an unsaturated compounds category for the more generic situation: perhaps Category:C=C (which is too cryptic) or category:compounds with a carbon to carbon double bond -- (which is a bit verbose). Compounds only with C=N or C=O would not be classified as alkenes at all. You can see that I used category:unsaturated compounds for Trans-4,5-Epoxy-(E)-2-decenal, but that is perhaps too generic. Graeme Bartlett (talk) 08:41, 24 June 2017 (UTC)
As a non chemist, could I say I don't think Category:C=C is too cryptic (subject to a short description on the category page). Unfortunately there is an element of genius in the idea which will inevitably lead to strong opposition from the dull minded. Bosley John Bosley (talk) 10:08, 24 June 2017 (UTC)
I was thinking of creating either Category:Alkene derivatives or Category:Alkenes (hydrocarbon). OrganoMetallurgy (talk) 12:48, 24 June 2017 (UTC)
I quite like Category:Alkene derivatives, (it is clear and not too long) then we can have lower levels of Category:unsaturated fatty acids, Category:Enols, Category:Alkenones, Category:unsaturated dicarboxylic acids. etc Graeme Bartlett (talk) 07:28, 25 June 2017 (UTC)
Graeme's suggestion here seems ideal to me. -- Ed (Edgar181) 14:30, 25 June 2017 (UTC)
I can do it tomorrow. OrganoMetallurgy (talk) 17:47, 25 June 2017 (UTC)
@OrganoMetallurgy: Very nice, but it seems that the hierarchy is wrong. Per WP:SUBCAT, shouldn't the narrow definition be a subcategory of the wide (since it's a strict subset) rather than vice-versa as it is now? If there's a good encyclopedic reason to do it the other way around, I'm quite happy to WP:IAR, but I'd like to have the reason explained. 104.153.72.218 (talk) 05:18, 27 July 2017 (UTC)
Frankly speaking, I'm not quite sure. I can see reasons for it going both ways and that's part of why I started this discussion. One reason to keep them the way they are is that it's more convenient/practical to have categories for substituted derivates of a parent molecule or class of molecules be a subcategory of a category containing the parent molecule or molecules. For example the category Category:Cyclopropanes, which contains molecules containing one or more cyclopropane rings in their structure, is a subcategory of Category:Cycloalkanes even though it contains molecules that aren't, strictly speaking, cycloalkanes, but it belongs there because cyclopropane, the parent molecule of cyclopropanes, is a cycloalkane. So it makes sense to have the category for substituted alkenes, Category:Alkene derivates, be a subcategory of Category:Alkenes even though alkenes (refering to the class of hydrocarbons) might be consided a strict subset of substituted alkenes if they aren't excluded by definition (which they might be). However moving the current Category:Alkenes to Category:Alkenes (hydrocarbons) and then moving Category:Alkene derivatives to the newly vacated Category:Alkenes would also be fine and would mostly resolve issues regarding WP:SUBCAT, although it might be necessary to come up with new guidelines to fully resolve the issue. OrganoMetallurgy (talk) 17:44, 27 July 2017 (UTC)

Is this 5-membered ring aromatic?

Is the 5-membered ring here aromatic?

@DMacks: Thanks for your comments and catching that typo.

I've been cleaning up a number of unnecessarily convoluted SMILES formulae (I try to minimize the mental "stack space" required, minimizing the depth of parenthesis nesting, and then the length of parenthesized groups, mostly by changing "foo(abra(cad)abra)bar" to "foo(bar)abra(cad)abra"), and I came across the page for metamizole, which had both rings marked as aromatic. Several similar compounds I had edited (removing unnecessary chirality indicators from the ring double bond; trans-cyclopentene is not a thing) do not mark that ring as aromatic.

The ring is similar to pyrazole, but desaturated so it only has a single double bond. I haven't kept up since undergraduate organic chemistry, but generally I expect aromatic rings to have 3/6 or 2/5 double bonds in their Kekulé form, which delocalize to form effective 1.5 or 1.4 bonds. Can a single extra electron pair make 5× 1.2 bonds?

I have a hard time counting the π electrons, but if pyrazole obeys Hückel's rule and we remove one double bond, that's removing one electron pair from the ring and should make it antiaromatic, no? Or does that carbonyl do something magic?

For wikipedia, it boils down to whether I write that as c1ccccc1N2N(C)C(C)=C(C2=O)N(C)CS(=O)(=O)O or c1ccccc1-n2n(C)c(C)c(c2=O)N(C)CS(=O)(=O)O, but I'm also personally curious. 104.153.72.218 (talk) 06:58, 27 July 2017 (UTC)

  1. Pyrazole is unquestionably aromatic, the electron count is 6. The trick with heteroatoms is that the lone pair can be included if it is needed, but if it is not needed then it can usually be excluded. This is why pyridine is a decent base and pyrrole is not, as the lone pair is not needed for the aromatic system in pyridine and so is a Lewis base, but the pyrrole lone pair is needed to get to 6 π electrons and so is unavailable to act as a base.
  2. For the five membered ring you show, the problem is not the π electron count, which can be 6 by including both nitrogen lone pairs. It is whether the system is cyclic in the sense of whether there is continuous cycle of sp2 hybridisation for the electrons to circulate through. If the ring carbonyl was reduced to an alcohol (and thus became sp3 hybridised), the system would definitely not be aromatic. However, the carbonyl C is sp2 hybridised and if the carbonyl π electrons can be contributed to an aromatic system then we can potentially still have 6 π electrons by only utilising one N lone pair. The 'unused' lone pair would not be in a hybridised orbital away from the aromatic system (as it is in pyridine), however, it would be in the p orbital orthogonal to the plane of the ring, and that p orbital would be needed for the cyclic system – in which case the electrons would be in the aromatic system. The same problem arises with the carbonyl π electrons if we try to include both N lone pairs and exclude the C=O π-bond – the carbonyl π molecular orbitals is needed for the cyclic system and so the electrons will be in the system.
  3. Short version: I don't think the 5 membered ring in metamizole can be aromatic because either the carbonyl is excluded and so there is no cyclic system of lone pair p orbitals and sp2 hybridised orbitals (as is the case for non-aromatic cyclopentadienone, for example), or it is included and we have 8 π electrons as both N atoms have their lone pairs in the unhybridised p orbital.
  4. Further reflection / addendum: If you consider the zwitterion formed by using the lone pair on the N adjacent to the carbonyl to form a C=N double bond, then that N atom carries a formal positive charge and the O becomes formally negative. The resulting 5 membered ring has two double bonds and has access to the lone pair on the other nitrogen and so does meet all criteria for aromaticity. Since this change is merely a rearrangement of electrons it follows that this zwitterion is a potentially significant resonance contributor.
  5. I am not certain, and accept that I may be wrong. This is an interesting question, because the structure as drawn does not appear aromatic but it has a resonance form that should be aromatic. I welcome other input and views, because I am also curious.  :) EdChem (talk) 08:38, 27 July 2017 (UTC)
(edit conflict) The zwitterionic resonance structure where the amide nitrogen atom is positively charged and the amide oxygen atom is negatively charged ([O-]C1=[N+](C)NC=C1) results in a aromatic 6π electron system ([O-]c1[n+](C)[nH]cc1). This is somewhat analogous to 2-pyridone (the tautomer is aromatic). Boghog (talk) 08:46, 27 July 2017 (UTC)
The tautomers of 2-pyridone are closely balanced in energy and the predominate tautomer depends on the substituents. In the case of metamizole where both forms contribute to the structure, the system is at a minimum partially aromatic. On the other hand, heteroaromatic SMILES sometimes causes problems with chemical depiction software, so it is safer to write the non-aromatic SMILES. Boghog (talk) 09:01, 27 July 2017 (UTC)
@EdChem and Boghog: Thanks for both your replies. I'm starting to believe that it likely is at least weakly aromatic, but I think Boghog's point about the likelihood of confusing software is a good one and it's better to use the non-aromatic form regardless of pedantry. 104.153.72.218 (talk) 10:24, 27 July 2017 (UTC)
I agree that the non-aromatic SMILES form is wiser for software interpretation reasons. EdChem (talk) 13:01, 27 July 2017 (UTC)
  • I'm fairly sure pyrazolones possess a degree of aromaticity. I think what User:EdChem is trying to describe in point 2 is cross-conjugation but that's rarely an issue in a mono-cycles. Pyrazolone can tautomerise between several different forms, with strong solvent selectivity. I think the far right form dominates on average. The 'phenol' form is quite common in certain azo dyes (Tartrazine, Orange B , Mordant red 19, Yellow 2G) as it tends to coordinate intramolecularly to the azo group to form a pseudo-6-membered ring.--Project Osprey (talk) 21:31, 27 July 2017 (UTC)
Tautomers
Pigment Yellow 10
Project Osprey, what you might be seeing in my comments is a degree of confusion because I looked at the structure as-drawn and posted before recognising the resonance issues with the zwitterion. I was also trying to explain my, perhaps somewhat incoherent, thought process as I had no idea of the IP editors level of chemical knowledge. The zwitterion resonance contributor convinces me that there is aromaticity in the 5-membered ring of metamizole, though I think Boghog's point on software interpretation makes the non-aromatic SMILES representation preferable. I certainly agree with you that pyrazolone possess aromaticity in some degree as evidenced by the tautomerisations you illustrate, though metamizole's heterocycle has no hydrogens available for latam-lactim or keto-enol type tautomerisations. EdChem (talk) 00:55, 28 July 2017 (UTC)

Lectins

The rise of the fad "lectin-free" diet means the lectin article is getting a huge surge in views recently. The page is currently tagged with a {{technical}} template, and focuses a lot on the toxicity of a small number of lectins. I'm trying to make it clearer to the lay reader (and make clear that the lectins in cooked food are not toxic and that the diet is potentially very dangerous), but it's a bit beyond my knowledge. Any help would be very appreciated. (cross-posted to Wikipedia talk:WikiProject Biology) Smurrayinchester 11:14, 28 July 2017 (UTC)

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