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Several members of the International Steering Committee of the Symposia on the Jahn-Teller effect have made large edits to (surprise!) Jahn-Teller effect. The additions are well written and well referenced but expansive and highly technical. So technical in fact that the effects that I've always associated with JT-effect like high-spin low-spin distortions simply aren't discussed. These changes were also made as one massive edit (+43,242). It would seem a shame to remove expert understanding from the article but I think we may need to reinstate parts of the original page to make it more accessible... maybe under some sort of 'overview' heading? There is a discussion at the talk page. --Project Osprey (talk) 23:02, 16 December 2016 (UTC)[reply]
One approach - some might think too drastic - is to revert their entire edit. And ask/demand/cajole them to make changes incrementally, lower the technical level (its impossible now), and - get this -- actually explain or justify their edits. I will do this and wait to see if and how they respond. If they dont, then some of us bring in the parts that are intelligible. If fellow editors think that I am being rash, then re-revert. No hurt feelings.--Smokefoot (talk) 23:38, 16 December 2016 (UTC)[reply]
I think it's safe to assume good faith in all this. The re-write was done as a draft (Draft:Jahn-Teller effect), it's transclusion as one massive edit seems to be due to a procedural error - they wrote the draft and submitted for review, but were told that as the topic already exists they should edit there directly, so they did. Incremental changes can be seen at the Draft history, although there are no edit summaries; work started in September. Considering the effort that must have gone into it I imagine they'll want a positive outcome. --Project Osprey (talk) 00:39, 17 December 2016 (UTC)[reply]
Absolutely I assume good faith. But one can act with good faith and still do something ill-advisedly. My thinking is that we current editors have little ability for making the article better, and just maybe we'll get them to do it as the price to rescue their work. The downside is that, what, 4-6 people in the world who want to know the intracacies of the J-T effect in the next few weeks will be inconvenienced. It is also instructive to look at the German version.--Smokefoot (talk) 04:18, 17 December 2016 (UTC)[reply]
@Smokefoot:, @Project Osprey:, I propose the content introduced by Janette Dunn at Nottingham be moved into a Talk entry (using collapsed markup), and that the issues of its sourcing, its gradual introduction, and its level of expertise and language be addressed from there. It is great material, and certain to improve the article in the long run (as it is expert both in scope and detail). But it would be a serious error, in my opinion, to begin to allow large blocks of unsourced material, even from experts, as I have stated to Janette, and to Smoke, at their respective Talk pages. Moving it to a collapsed section in Talk and leaving the earlier article will restore a stable, if marginally expert and marginally sourced article. But it will allow moves of material from the Talk archive as source, into the article main space, a section at a time, where we can, over time, ensure sourcing and proper level of newly introduced material. This accomplishes all purposes—use of the expert material, improvement of the article, submission to WP guidelines, etc.—with minimal work. Meanwhile, I am going to engage JD offline, and ask if a couple of their students can be assigned to provide good secondary sources for the material already posted. Cheers. Le PRof Leprof 7272 (talk) 04:47, 22 February 2017 (UTC)[reply]
I recently wrote an article on pyrithione which exists as a pair of tautomers (at right). Based on this source published by the University of Barcelona, I put pKa values of "−1.95 and +4.6 (thiol proton)" in the article. I can find sources supporting the 4.6 value, but not for the −1.95 value. Petergans has challenged it on the article talk page, but he cannot access the book source on google (I can view it from Australia, so access depends on the location of your IP address). The reference the book provides supporting the claim is no. 40, which should appear on page 356, here, but I cannot see that page to look to the source's source. My initial interpretation was the two values are for the two tautomers, as it seems reasonable to me that the thiol tautomer would be a weaker acid than the thione, and the greater ionisation of the thione would account for it being the major tautomeric form (despite the aromaticity of the thiol). However, the difference in values is very large and Petergans is correct that −1.95 is into the strong acid range. Can anyone explain why there are two values, as the quoted source suggests? Alternatively, should we remove the second value and just list +4.6. If so, should we make some note / comment about it? Thanks to all. :) EdChem (talk) 00:23, 19 January 2017 (UTC)[reply]
I can't access the book. Scifinder has no pka info for the thione form but gives 4.49 for the thiol with this source doi:10.1016/j.jinorgbio.2006.05.003. The page states that the thione form dominates, that's a big surprise to me (surely aromaticity always beats cross-congregation?) but the ref is for the solid state and that's its own weird area, any idea if that holds true in solution? --Project Osprey (talk) 10:03, 19 January 2017 (UTC)[reply]
Ref 40 is "R. Alan Jones; A. R. Katritzky (1960). "N-oxides and related compounds. Part XVII. The tautomerism of mercapto- and acylamino-pyridine 1-oxides". J. Chem. Soc.: 2937–2942. doi:10.1039/JR9600002937.". This indeed supports 2 values (-1.95 and 4.67; both averages of 6 independent values, both sigma of 0.03). If I read it correctly, the -1.95 is measured at high dilution (0.5 . 10^-4 M) using sulfuric acid or phosphate buffers with a spectroscopic method, the second is a potentiometrically determined value at high concentration (239 . 10^-4 M). Please have a proper look at the reference before using it, the interpretations of these pKa measurements are outside of my confidence zone. --Dirk BeetstraTC10:57, 19 January 2017 (UTC)[reply]
I have seen the page where a pK value of -1.95 is cited, though it is described as pK1 rather than pKa. A value of pKa of -1.95 is to be associated with a rather strong acid. Does the protonated form of the compound [C5H4N(OH)(SH)]+ form at pH 0 and less? Petergans (talk) 11:57, 19 January 2017 (UTC)[reply]
This is an area where I have some experimental and theoretical expertise. Call on me somehow, if you cannot settle on a good course here. Cheers. Le Prof Leprof 7272 (talk) 04:54, 22 February 2017 (UTC)[reply]
new article "Glaring Chemical Errors Persist for Years on Wikipedia"
It gives 3 examples, all structural errors in images. The author (@Mandlerm:) did correct the errors he found; however despite encouraging more people to edit in the paper he hasn't returned since making those 3 fixes in September. Bit of a cheap shot really. --Project Osprey (talk) 10:59, 1 February 2017 (UTC)[reply]
It's not just that he didn't keep up his good work after fixing these three articles on en.wp. His fix was to redraw the images and replace them in the articles on en.wp. Good! But in the JChemEd article, he also noted that one of the images was tagged on commons as having a mistake. He didn't even tag the other ones likewise, leaving those images themselves (and the other WP sites that use them) just as likely to misinform readers as before. Can't fault someone for not doing volunteer work, but it's a weak position to leave a problem present that you know how to fix (or at least alert others to fix) and then loudly complain that there are problems that someone should fix. For the record, I fixed two of the images on commons. This set of changes I don't have time to work on right now. DMacks (talk) 16:04, 1 February 2017 (UTC)[reply]
V8rik is exactly right. Many of us do more editing in a week than Mandern expended in a lifetime on Wikipedia, and we dont try to get some %$*ing publication for our efforts. Now that I have that off my chest, I will point out that I see many high level chemists consulting Wikipedia all the time. And increasingly images from Wikipedia are creeping into lectures, sometimes even with attribution.--Smokefoot (talk) 20:46, 1 February 2017 (UTC)[reply]
From the abstract: "Even when these mistakes are discovered and reported, articles are sometimes subsequently left uncorrected."
This goes without saying, though? We're all volunteers here. I fixed images here and there, and it often took hours. You check the reference of the image, you redraw the image (and often make it clearer for undergraduates, also with colors), you upload it, you put some explanation, etc.
It's sad that Michael Mandler looked for a shortcut to his 15 minutes of fame by belittling a community he knows nothing about. In Donald Trump's style of tweet: VERY SAD!
Thank you (seriously) for your critical comments on this page. I only recently got into Wikipedia editing and I have tremendous respect for you all. I'm not great at Wikipedia software, but I will continue to make edits on chemistry articles as soon as I find them. I agree wholeheartedly with Georginho; fixing images takes hours. If you have Chemdraw, obviously this task is much easier, but I assume most people may not have this software. However, I do want to point out to Georginho that I did not mean to belittle the Wikipedia community at ALL.Mandlerm (talk) 16:58, 5 February 2017 (UTC)[reply]
@Mandlerm: I see you did not cite a source for the "upset guy" who is looking at the Pfitzner–Moffatt oxidation mistake in the abstract-image. Did you draw it yourself? DMacks (talk) 16:23, 14 February 2017 (UTC)[reply]
Some good news. Over at WT:CHEMICALS there is an extensive discussion about data quality wrt exteranal databases (like PubChem DB). Over at Wikidata, smart bot operators have imported 170k(!) PubChem CID identifiers, names, and their properties. A task at hand now is to check the PubChem CID with the enwiki value (in ~17k {{Chembox}}, {{Drugbox}}). Now it appears that a serious number of PubChem database values are incorrect. We cannot blindly import the PubChem data into our infoboxes (from Wikidata). So there are errors in external database(s) too (for years?). The good news is that Wikipedians are mass-analysing that data to improve the quality. It's good for PubChem too. -DePiep (talk) 09:06, 3 February 2017 (UTC)[reply]
A rebuttal when there has been delivered? (could be 202x). I have no rub with Mandlerm or their publication. These opinions and judgements about WP happen often, and their core is not faulty. I'd say let's keep working on individual articles, and general setups like WD and infoboxes. JChemEd does have other WIkipedia publications too, I hope. -DePiep (talk) 11:12, 3 February 2017 (UTC)[reply]
The paper is 2 years old. Are there any tasks left to improve Wikipedia chemicals? Or is this a welcome check/approval on the quality of SMILES in enwiki? -DePiep (talk) 14:38, 6 February 2017 (UTC)[reply]
My advice, don't shoot the messenger, and be thankful that he did not contact anyone more seasoned at WP to provide observations to support his article. Any one of us, certainly, could share tens if not hundreds of further known issues within chemistry articles, where accurate representation via images is a clear leading area (because try as we might, we all all do not have ample time, every time we come upon an issue, to address it thoroughly, by going offline, and creating new, corrected images). But other areas of article shortcomings are just as real, the most egregious in my view being the non-authoritative scope of many articles, i.e., their not covering things they should, and covering things they need not (along with the article structural issues that follow from such omissions and insertions). No, I think this JCE writer does us a service, and I wish more academics would take even the time that he did. Truth is—and this is Le Prof the academic, speaking, now, and not Le Prof the editor—no organic chemist worth his salt would send anyone to WP to get their start on a subject. (With Clayden, Greeves & Warren available, why would we?) The material is simply not worth the time it takes for a supervising tutor or instructor to correct or fill in the inadequacies that exist in WP materials. (I say so just about this, in one of my principle areas of expertise.) And in the end, it does not matter why errors persist—with time to discover, lack of expert feedback, WP momentum, politics sometimes embroiling change, difficulty of accessing better images or authoritative resources, lack of expert editors to make the changes, etc.—it is simply true that substantive errors in scope and detail persist. Respect you all, Smoke, V8rik, Dmacks, Osprey. But this is my opinion. Cheers. Le Prof Leprof 7272 (talk) 05:04, 22 February 2017 (UTC)[reply]
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
Back in 2015, I complained about the confusing shortcuts for chemistry-related Wikiprojects, but participation was pretty low. So let's have a full RFC and decide what to do. I'll just copy-paste my original post, those who commented on the original post (Sizeofint (talk·contribs), DePiep (talk·contribs)), and advertise the RFC at other related projects.
Currently, we have the following redirects to WP:CHEMISTRY
There are other redirects as well (and lowercase variants), but they don't matter for this discussion. I put forward the claim that WP:CHEMS/WP:CHEM/WP:CHM are ambiguous and we should do something about it. In particular, when I see 'CHEMS' I'm thinking 'chemicals' as in 'did you order the chems?', and when I hear 'CHEM', I'm thinking chemistry as in 'Chem classes this afternoon?' or 'CHEM3000'. CHM I'd be ??? / leaning chemistry just because sometimes CHM is a class code instead of CHEM. And I'm tired of being brought to the 'wrong' page when I put WP:CHEM in the search box. If figure if this is confusing to me after years of editing and hundreds of thousands of edits, this surely is confusing to newcomers as well.
I suggest we either
1) Re-target WP:CHEM to point to WP:CHEMISTRY, and WP:CHEMS to point to WP:CHEMICALS. Then make WP:CHM point towards a dab page. We can use bot cleanup to 'retroactively enforce' the new convention, so old links still point to the intended target.
2) Endorse a new WP:CHEMIS and WP:CHEMIC. We use bot cleanup to enforce the new convention, so newcomers are only presented with the current shortcuts to reduce confusion.
a) We leave old shortcuts as they are, we just don't mention them anywhere 'visible' (like the front page of WP:CHEMISTRY/WP:CHEMICALS.
b) We retire the old shortcuts, making all of them point to a dab page.
The downside of 1) is the "old fart factor". We have habits, and this would require veterans of these projects familiar with the current convention to change their behavior. There's a transition issue, but it should resolve itself after a month or two.
The downside of 2) depends on the sub-option chosen. Each have their pros and cons.
a) Requires the least amount of change from anyone, at the cost of the old abbreviation slowly creeping back into use over time because nothing is done to warn anyone WP:CHEMS/WP:CHEM/WP:CHM are kinda ambiguous and shouldn't be used.
b) Requires vets to adapt, but there's a dab page to help the 'victims' of those didn't.
c) Requires vets to adapt.
The downside of 3) is the current mess that we have.
option 4 (added)
4) Use WP:CHEMY for Chemistry. Abandon WP:CHEM for being ambivalent (requires prior knowledge).
Ambivalent shortcuts lead to the new Disambiguation page: WP:CHEM, WP:CHM. Correct variant WP:CHEMICAL can stay, but should not be promoted.
Option 1, clearly. After I read what redirected to what, that exactly the action that came to my mind. I am skeptical about Chemis/chemic because nobody says that as far as I know.--R8R (talk) 16:30, 14 February 2017 (UTC)[reply]
Changed to "oppose all". The shortcut "CHEM" is ambiguous, so does not help me at all. Only a halfway solution = not a solution. See discussion. -DePiep (talk) 07:32, 15 February 2017 (UTC)[reply]
I got complaints that this could be a PA. IMO, I just jokingly responded to the 'no-brainer' concept, not the author. Was I? -DePiep (talk) 22:32, 15 February 2017 (UTC)[reply]
Option 1 – In the beginning (of my Wiki life) I was confused about the redirects too. Especially that "chem" redirected to chemicals. IMHO, Chem is chemistry for the majority of English-speaking people. Going to chem class etc. Christian75 (talk) 22:34, 15 February 2017 (UTC)[reply]
Sizeofint: re I don't see a reason to redirect CHM: I do. Can you say what everyone else should expect to arrive at, when clicking CHM: chemy or chems? -self edited:- When it would arrive at CHEM, I say: Redirect to the dab-DePiep (talk) 00:04, 25 February 2017 (UTC)[reply]
I'm ambivalent about it, not necessarily opposed. As long as we're developing a bot to change all the links I suppose this might as well be done too. The consensus seems to be leaning that way anyway. Sizeofint (talk) 01:37, 25 February 2017 (UTC)[reply]
Option 1 is clearly best if it works. How easy will it be to get a bot to amend all links, including on archived discussion pages? I think it would be a mistake to render some past discussions incomprehensible – maybe I'm an old fart. Maproom (talk) 08:30, 19 February 2017 (UTC)[reply]
Option 1 seems sensible to me, I certainly use "chem" as an abbreviation for the subject chemistry rather than for chemicals. EdChem (talk) 12:04, 19 February 2017 (UTC)[reply]
Option 1 is fine, and vis-a-vis "chem", consistent with the shorthand used in most English-speaking departments globally. And the consensus seems clear. Leprof 7272 (talk) 04:00, 22 February 2017 (UTC)[reply]
I hate to mess with shortcuts people are used to using, but Support swapping CHEM and CHEMS with bot cleanup of existing usages. I definitely consider it a mistake that CHEM didn't point to Chemistry in the first place. I'm neutral on CHM. Making it a DAB is reasonable, but I'm not sure I see any worthwhile need to mess with the existing usage. Alsee (talk) 07:04, 23 February 2017 (UTC)[reply]
Please please, really really, read this. Before or after that swap: I do not have a clue which main topic or WikiProject WP:CHEM would lead to. So what is the advantage of that úsed to' shortcut change? -DePiep (talk) 01:55, 25 February 2017 (UTC)[reply]
Option X The whole thing is a bit of a mess and the options for suggested change, though not in themselves pernicious, aren't great shakes as improvements, are they? WP seem to have migrated to a material improvement in the search feature, that provides alternative options as one types in your search entry. This is not in general sufficient for such short entries, but it does reduce the pressure for a solution. For the rest I strongly recommend a proper re-think along the lines of a chemistry/chemicals-related disambiguation page, that all ambiguous terms should wind up at, by a redirect if necessary. (Less ambigous redirs should follow the normal course.) Anything ambiguous (chem or chems for example) along those lines should appear in the page under the suitable articles header, so that most of the users who had been sucked in by the shortcut would need just one more click to find the article they intended. Less trouble for the one-fingered than typing "chemicals" instead of "chems" and a lot less trouble than winding up at Chemistry and not at first noticing it. (It happens, it happens, infuriatingly...) The layout of the Dab might be a little unusual, with possibly desired entries appearing in more than one place so that all the likeliest items are immediately visible after the first click, and the more obscure examples tailing off the page, but that should neither confuse nor frustrate anyone. An alternative would be to have a structure that AFAIK does not exist in WP, but perhaps should: A super-TOC for major projects such as Chemistry. It would contain the organised list of article links in a sort of TOC form, each with a one-liner explaining its content, possibly explaining alternatives hat-note style. It would NOT include redirects, but an entry might be something like: Chemical formula -- gives proportions of atoms in a molecule, OR see Structural formula for atomic spatial relationships Such measures would be very important for such huge projects, but I am not inclined to guess how useful they might be for smaller topics. If some such structure does in fact exist already then it should be used here. JonRichfield (talk) 09:10, 1 March 2017 (UTC)[reply]
Could we make it unused WP:CHEMY for Chemistryy, since WP:CHEMS is for Chemicals? An extra hint that would help me a lot. Then WP:CHEM should go to the dab too. -DePiep (talk) 16:46, 14 February 2017 (UTC)[reply]
not CHEM. I definitely don't want CHEM to be a shortcut. This still requires a mental step, uncessary. I propose to use unambivalent CHEMY for that one. All ambiguous shortcuts (think of this!) should lead to the dab page. -DePiep (talk) 07:31, 15 February 2017 (UTC)[reply]
For most people ... -- is what I'm trying to say. Those are people who are already very familiar with the topics and their relationship. For others, there is always confusion. Those who don't have the trained intuition, there will be mistakes and missed discussions. -DePiep (talk) 13:38, 15 February 2017 (UTC)[reply]
The question here is where would an editor (without pre-existing knowledge on how projects are structured)) expect to land on when if they enter WP:CHEM and WP:CHEMS in the search box. The usual abbreviation for chemistry is CHEM (or CHM),just like physics is PHYS (or PHY), and biology is BIOL (or BIO). This is true in class acronyms, in journal references (which use Chem, Phys, Biol), etc. So clearly CHEM should redirect to the Chemistry project, and CHEMS to the Chemical Project. You can't prevent people from using these shortcuts, but we can at least make them behave like the majority would expect. If you want WP:CHEMY on top of the others, there's nothing preventing us from also having that shortcut. Headbomb {talk / contribs / physics / books}16:06, 15 February 2017 (UTC)[reply]
"The question here is where would an editor (...) expect to land on". Let me say: Yessss to this. That editor is me. And I do not have "expectations", I am just reading a shortcut. Those 'expectations' you know(?) again, again, suggest prior knowledge. -DePiep (talk) 22:10, 15 February 2017 (UTC)[reply]
When I started editing, I expected CHEM to be a shortcut to the chemistry project. I think enough editors expect this link that it is more useful for to make CHEM a link to the chemistry project than to make it a link to a disambiguation page. Sizeofint (talk) 07:41, 26 February 2017 (UTC)[reply]
Above in !vote, User:JonRichfield nicely describes the troubles with ambiguous terms. The use of shortcuts is, that they should not rely on "I expect" for implicit disambiguation. -DePiep (talk) 11:56, 3 March 2017 (UTC)[reply]
I'm not sure there's actually an issue here. The two WikiProjects are closely related and share the majority of their editors. Anyone clicking those redirects will be trying to get in touch with the chemistry editing community - and which ever one they click they will succeed. For all the assignments are messy and arbitrary the result is perfectly functional, thus it seems like wasted effort to change them to something that will be no more or less functional. That said here's also no harm in it, but it feels like cruft to me. --Project Osprey (talk) 16:52, 14 February 2017 (UTC)[reply]
There is harm. In short, it splits discussions. (I've spend hours searching in the wrong project). OTOH, I don't see any harm in making the shortcuts relevant & related. -DePiep (talk) 17:34, 14 February 2017 (UTC)[reply]
Just to illustrate how confusing it can be, for others. At this momant, this talkpage has 24 entries (at level ==). Of these, some 8 are about chemicals:
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
@Fences and windows: thanks for bringing this to our attention. I was surprised to see the removal of the textbook by Zumdahl, though, it has long been used at tertiary levels and is reliable, as I understand it. EdChem (talk) 12:06, 19 February 2017 (UTC)[reply]
EdChem, if there's a genuine textbook by Zumdahl it's not published by Content Technologies Inc. I found that "edition" on Google Books and without doubt it copies Wikipedia. See WP:PUS for more such books. CTI appears to lift ISBNs and author names to pretend to be presenting real textbooks. Fences&Windows07:10, 20 February 2017 (UTC)[reply]
Fences and windows, you are right that that link is clearly a copy of Wikipedia. Here is a link to the 9th edition to the actual textbook by Zumdahl and Zumdahl published by Cengage, and there is no if as to whether it is a well-established and genuine textbook. I wasn't aware of this form of fakery, though, and it is annoying, wasting editors' time and I don't see the benefit to CTI of sticking such references into WP articles. :( EdChem (talk) 07:52, 20 February 2017 (UTC)[reply]
EdChem, my wording a bit throwaway, I didn't doubt there's a real textbook. Does it contain anything about the "Heylman equation"? I very much doubt it. CTI operate by selling "revision guides" and "textbook guides", capitalising on students who can't afford the real textbooks I assume. These references being used in Wikipedia is an unfortunate side effect - they're added by well-meaning but unwary Wikipedians, not CTI employees. Fences&Windows08:47, 20 February 2017 (UTC)[reply]
Fences and windows, I don't have a copy of Zumdahl to hand, but I have taught the H-H equation plenty of times and I don't recall hearing of the Heylman equation, nor do I see it in the couple of texts I checked. All the online sources I can find, including at Google Books, track back to copies of the WP article or to CTI, so I am very comfortable with your removal of the name. Thanks for explaining that the damage to WP content is from well-meaning Wikipedians rather than CTI, but the CTI profiteering on WP content does irk me. EdChem (talk) 12:28, 21 February 2017 (UTC)[reply]
Leaving Steve's book citation to others to sort, as expressed to F&W at the article Talk page, Mssrs Heylman and Lardinois are clearly two students at Wisconsin, with a reverting edit from IP clearly tracing there (and the students names both appearing in a 2016 commencement announcement). Relatively clear since this is not a case of a Smith-Jones. Bottom line, thanks for the persistent correction, and I'll send an email to these two to tell them to knock it off. Cheers. Le Prof Leprof 7272 (talk) 05:44, 22 February 2017 (UTC)[reply]
Primary, secondary, tertiary, quaternary – one term in English?
Hello, I'm from pl.wiki and I'm trying to figure out if there's one term in English which describes "primary", "secondary", "tertiary" and "quaternary"? In Polish we have "pl:rzędowość" ("pierwszorzędowy" = "primary", "drugorzędowy" = "secondary" etc.), but I was a little suprised when I saw (trying to link articles in Wikidata) that you have 4 different articles (Primary (chemistry) etc.) and I couldn't find any equivalent to "rzędowość" (as a matter of fact, I was much more suprised when I searched amines and alcohols in every available language and I couldn't find eqivalent terms anywhere). I would be grateful if you could help me in this matter. Wostr (talk) 22:59, 21 February 2017 (UTC)[reply]
It should etymologically be "quartary", which would come from the Latin ordinal quārtus "fourth". "Quaternary" comes from the distributive quaternī "four each; four at a time". But the words are similar and both come from Latin, so there must have been so much confusion that the etymologically wrong one became the standard term. Double sharp (talk) 04:10, 22 February 2017 (UTC)[reply]
I don't know a formal and well-established term. Possibly something like "degree of alkyl substitution"? German wikipedia has articles for each as well. @Leyo: (or any other German speakers), does de:Primär (Chemie) have a word or phrase for this concept? But I also question why we do have four separate articles. They are all clones of each other, merely changing the definition and highlighting a different column of the comparison table. If we had something to call the whole idea, I'd say we should merge/redirect all to it. DMacks (talk) 04:14, 22 February 2017 (UTC)[reply]
Hi, Carey & Sundberg use the imho correct term 'degree of substitution' (in german 'Substitutionsgrad') only once in their book ([2]). The substituent can be alkyl or aryl ([3]), and the term can be used on a carbon atom, a nitrogen atom or, i guess, even a molecule (e.g. on repetitive units of polymers - although here it isn't called primary but singly substituted). Cheers, --Ghilt (talk) 23:18, 22 February 2017 (UTC)[reply]
Here are the meanings of primary, secondary, tertiary and quaternary, from the OED:
"Of the first order in time or temporal sequence; earliest, primitive, original."
"Belonging to the second class in respect of dignity or importance; entitled to consideration only in the second place. Also, and usually, in less precise sense: Not in the first class; not chief or principal; of minor importance, subordinate."
"Of, in, or belonging to the third order, rank, degree, class, or category; third."
"Consisting of four things or parts; characterized by the number four; †quaternary compound, a combination of four chemical elements or radicals. (This sense is now Obs. in Chem.)"
In this calculation, k1/k2 = 10^(ΔΔG*/(temperature*1.98*2.3), where ΔΔG* = 1, 2, 3, 4, 5 kcal. This calculation does not represent OR, so if the values look legit, I propose to insert this table or something like it into an article on selectivity. One option would be to calculate and tabulate % selectivity. It is easy to make simple mistakes with this calculation, so if anyone sees a problem, leave a note. The reason for discussing this calculation in the articles is that it is used often in discussing catalysis, i.e. 1 measly kcal (1/4th of an hydrogen bond strength) can make a big difference.
Those numbers look about right and are not OR per WP:CALC. My brain is wired in kcal/mol, so I took the liberty of converting cals to kcals in your table above. Boghog (talk) 18:27, 23 February 2017 (UTC)[reply]
Here's a non-zeropadded way of decimal alignment. It's a "differently ugly" hack:
I had the sortability feature as a TODO, then wrote a test case on /doc and it was already working:) As a comparison, {{0}} has better performance and keeps numbers as single strings (better for searching using one's web-browser), but it requires that the editor determine and hard-code the padding for every entry. DMacks (talk) 10:16, 25 February 2017 (UTC)[reply]
Nice. Also, {{0}} does not consider font digit width: 12.111, 12.333, 12.000 might/will line up different with non-monospace fonts. -DePiep (talk) 12:06, 25 February 2017 (UTC)[reply]
Two thoughts. First, we should include ΔΔG*=0. But also, a graphical representation might be at least as, or more useful than, a discrete set of values in text. Using 1–6 kcal gives a great snapshot of the relative growth rates:
Adding the half-kcal intermediate values and hiding the data points might give a cleaner look. Accompanying this with 0–3 kcal at even higher x-axis resolution (0.2-kcal steps?) would let us see how it's fairly close but already separate even at low energy differences (Smokefoot's "1 measly kcal" comment). Obviously we could generate these as SVG in a mathematical plotting program. But while we're talking about presentation tricks, figured I should mention {{line chart}} for quick'n'dirty work:) DMacks (talk) 04:52, 26 February 2017 (UTC)[reply]
...or just use a better grapher altogether...
Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.
Many thanks to DMacks especially, but the group in general, for really advancing this presentation goal. The main problem with the graph is that it fails to show effects on k1/k2 in the 1-3 kcal range which is most relevant. --Smokefoot (talk) 02:39, 27 February 2017 (UTC)[reply]
I agree. I've just been using exactly the values Boghog gave in the original table. What is the derivation of the k1/k2 = 10^(ΔΔG*/(temperature*1.98*2.3) equation? I assume 1.98 and 2.3 are not arbitrary and unitless numbers:) If nothing else, we need to establish if ΔΔG* is in "kcal" (per molecule?) or "kcal/mol". But also, should it be ΔΔG‡ (double-dagger vs asterisk)? I looked at activation energy#Relationship with Gibbs energy, but the sentence there:
the Eyring equation uses the concept of Gibbs energy and the symbol * to denote the energy of the transition state
The graph look right, it's just that the effects are not obvious from this presentation. Most enantioselections rely on just 1-3 kcal/mol, which gives acceptable selectivity. The formula is derived as Ed mentioned: k1/k2 = e(ΔG1‡/(RT)/e(ΔG2‡/(RT)--Smokefoot (talk) 13:56, 27 February 2017 (UTC)[reply]
That looks tiny. I use "•" in superscript form H• which looks like your second option. I added it to my clickable symbols when editing. "·" also is too small. Graeme Bartlett (talk) 21:01, 2 March 2017 (UTC)[reply]
Notation of radical dots in mhchem package. It's a Mediawiki bug. Original mhchem package use bigger dots. I'll changed the dots temporarily. -- Cedar101 (talk) 09:02, 3 March 2017 (UTC)[reply]
Can the LaTeX users consider using a sans-serif font? Helvetica the default for Am. Chem. Soc. artwork. And generally easier on the eyes for chemists.--Smokefoot (talk) 15:30, 3 March 2017 (UTC)[reply]
Use roman type for the symbols for chemical compounds.
ACS is not us. For chemistry articles at least we should use sans-serif font. If it can't use it, then we should not be using it here, otherwise the style is too much of a missmatch. Graeme Bartlett (talk) 11:59, 6 March 2017 (UTC)[reply]
I have discovered the articles Lyotropic liquid crystal and lyotropic. Originally I found the second one but whilst I was trying to improve it I have realized the existence of also the first one. I suspect they can be merged, I don't recall any use of lyotropic outside of the description of lyophases. Do you agree?
Also lyophase could be created as a redirect. Any comments?
Don't expect a great improvement BTW, just some reorganization of the content and maybe I can add one or two sources of some scientific article I have on my laptop now.--Alexmar983 (talk) 14:50, 3 March 2017 (UTC)[reply]
I made the redirect. If noone gives any feedback, I merge the articles probably by the end of the week end. Let me know (ping me if possible).--Alexmar983 (talk) 08:32, 4 March 2017 (UTC)[reply]
I have added something on the main article. Tomorrow I complete the merge. I did not have a lot of peer-reviewed materials on my computer to use, but I hope what I have added it good enough. Basically this guy, inactive since 2008, it is the one who improved some articles of lyotropic mesophases, and that specific one was probably not really improved since 2007-8. So sad.--Alexmar983 (talk) 17:19, 4 March 2017 (UTC)[reply]
Merged, although the articles is still far from decent. Let's hope that the combined visits act as a catalyst for a better improvement in the future. --Alexmar983 (talk) 06:39, 5 March 2017 (UTC)[reply]
In days of yore there were examples like Wiberg's Inorganic Chemistry (2001 trans. of 1995 German 101st edition); Greenwood & Earnshaw's Chemistry of the Elements 2nd ed, (1998); and Cotton et al.'s Advanced Inorganic Chemistry 6th ed. (1999).
There a few more recent examples, like Rayner-Canham and Overton's 6th ed. (2013), Descriptive Inorganic Chemistry; and Housecroft and Sharpe's 4th ed. (2012) Inorganic Chemistry, but neither of these are as comprehensive as the earlier examples.
Whenever I base something on the big three I mentioned in my opening paragraph I wonder what developments have occurred over the past 15 years or so that I may have overlooked.
I can search the literature but that is nothing like being able to check a recent descriptive chemistry tome. I'd look up the most recent edition of Wiberg's Inorganic Chemistry (2016, 2622 pages) if I could read German.
The comprehensive inorganic sources that you cite - Wiberg, Greenwood & Earnshaw, Cotton & Wilkinson - remain excellent sources for basic inorganic chemistry, IMHO. They are the backbone of much of Wikipedia's content focusing on the structure of simple (especially purely inorganic) compositions. I am not aware of any gaffes in these books.
Particularly rapid developments are associated with "hyphenated" areas such as organometallic, bioinorganic, and materials chemistries, but the fundamentals described in the big three remain a good starting point. Comprehensive books on organometallic chem include Hartwig's Organotransition Metal Chemistry: From Bonding to Catalysis and on main group chem (Steudel, albeit in German: Chemie der Nichtmetalle, 4th edition.
Option B - I vote against indicating states in equations. My reasons: 1) Few textbooks/journal do this. 2) Adding states makes a difficult subject (a chemical reaction) more difficult. 3) Many reactions are pretty indifferent to state (within the temp-pressure realm intuitive to chemists), 4) anti-clutter. If memory serves me, we discussed this topic a long time ago. --Smokefoot (talk) 22:18, 7 March 2017 (UTC)[reply]
Smokefoot, I think Headbomb is pointing to something else. Check how the superscripts change position: from next-to to right-above. Two sets to compare: A-A2 and B-C(a) and (b). (The states are not changed). -DePiep (talk) 22:26, 7 March 2017 (UTC)[reply]
Oh, I am really losing it. Well, I said my piece anyway about the states, which respond part of the question, which would be moot. --Smokefoot (talk) 23:56, 7 March 2017 (UTC)[reply]
That answers no part of the question at all actually. I don't really know how things are usually presented in chemistry, so I want to confirm what is the better format before doing an AWB run. If you have HSO3− , which to my understand means (HSO3)−, wheras HSO− 3 could possibly be seen as HS(O− 3). However I don't know the ins and outs of chemistry conventions, and it's possible no one would ever be confused since charge always refers to the whole molecule. How is this done in the literature? Ion#Common_ions seems to suggest HSO− 3 is preferable to HSO3−. Headbomb {talk / contribs / physics / books}03:12, 8 March 2017 (UTC)[reply]
ACS Style Guide (I have 2997 edition at hand) instructs to stagger not align. I used to see the aligned version held up as more formal because that idea was conflated with "more difficult to typeset", i.e., for no good reason at all. In terms of wikipedia's specific implementation, {{su}} makes more of a mess of line spacing. DMacks (talk) 03:26, 8 March 2017 (UTC)[reply]
I just looked at the IUPAC Red Book / Green Book, as well as a couple of journals, and they all seem to mostly use HSO3−, but not always [possibly due to a typographical error, however]. So I guess I'll look for X± # and replace those with X#±. Headbomb {talk / contribs / physics / books}03:45, 8 March 2017 (UTC)[reply]
{{Chem}} does vertical stack: {{chem|SO|4|2-}} → SO2− 4
However, {{Chem}} has that COINS warning in top ('do not use in a reference') that is unspecified.
We could use HTML guidance for this, before we think we have a chemistry choice. How does <chem> handle this? It is morte recent, so there might have been a new (chemistry) discussion. -DePiep (talk) 08:26, 8 March 2017 (UTC)[reply]
We shouldn't base ourselves on <chem>/{{chem}} if the behaviour is wrong (and it's easy to produce a different input with the chem tag, you just need to use it properly, e.g. <chem>{HSO_3}^-</chem> → . IUAPC and chemistry journals usage is, AFAICT, 99% HSO3− over HSO− 3. So it's very likely we need to update <chem>/{{chem}} usage and behaviour.Headbomb {talk / contribs / physics / books}11:56, 8 March 2017 (UTC)[reply]
Stacked Superscripts and Subscripts tuning in mhchem options<chem>(e.g. ) of current mediawiki version isn't follow the default option. It's a kind of bug. -- Cedar101 (talk) 04:24, 9 March 2017 (UTC)[reply]
Looking at about 10 textbooks I have, most use staggered form, but two used stacked. The mass spectroscopy book even stacked the + and the radical • which suggests for example that for superoxide ion we may need − • and 2 stacked three high instead of O2•−
Not wide enough. This way we'll keep stumbeling. <chem> is mw wide. {{chem}} still has that COINS warning. In this mini-research discussion, some source glancing is used. Time to solve chemistry, typography and HTML effects altogether. -DePiep (talk) 12:28, 8 March 2017 (UTC)[reply]
Just for context, I checked a few old editions of Brown, LeMay, Bursten and Zumdahl and Hill and Petrucci and they all use both conventions; for ions, they stagger, like NH4+ and for other uses they stack, like Eo cell or ΔHo 298. --Jayron3213:17, 8 March 2017 (UTC)[reply]
The last two are variables, which isn't what we're talking about here. On variables, it's standard/best practice to align superscripts, since they both apply to the same variable and have equal hierarchy. Headbomb {talk / contribs / physics / books}13:24, 8 March 2017 (UTC)[reply]
Just to be clear. At this moment: Headbomb nor anyone else has a permission to blanket form chemical formulae either way. -DePiep (talk) 22:10, 9 March 2017 (UTC)[reply]
{{Chem2}} uses stacked too (the {{su}} was copied from {{chem}}:
The correctness of the display is the primary concern. Everything else is secondary. Right now it seems fairly clear that the charge should be misaligned. The question now is should states be misaligned? I'd argue they should be aligned with the charge, since both apply to the overall molecule (e.g. H3 O+ (aq) / NH 4+ (aq), implying (H3 O)+ (aq) / (NH 4)+ (aq)), but maybe H3O+(aq) / NH4+(aq) is preferable. Again, the question is what is done in the literature? Headbomb {talk / contribs / physics / books}20:28, 18 March 2017 (UTC)[reply]
"correctness of display" - why not, for example, semantics?
Anyway, establishing what is "good" requires a broader lookaround. I don't think 'it seems fairly clear' is enough. -DePiep (talk) 21:16, 18 March 2017 (UTC)[reply]
Reactionbox type
Hi guys. Whilst working through red-linked categories I've come across ZACA reaction, which since its creation in 2011 has been generating a red-linked category in contravention of WP:REDNOT because the type parameter of its {{Reactionbox}} is set to "transition metal catalyzed organometallic functionalization". AIUI the point of Reactionbox is to confine descriptions to a certain standard set, could someone adjust it appropriately? If nothing else, any phrase involving words as horrible as "functionalization" need to die...... Le Deluge (talk) 23:34, 11 March 2017 (UTC)[reply]
Most of the above articles are inappropriate, as the topic is too narrow, so that no one has written on it before. Perhaps some can be broadened by renaming and extending to cover topics that others have written about. Waht we have at the moment is mainly WP:Synthesis with essay-like material. They may be suitable for Wikiversity. I tried to redirect a couple to broader topicss, but perhaps AFD is the way to proceed. Graeme Bartlett (talk) 04:56, 24 March 2017 (UTC)[reply]
Should we write a ChemEd paper about running class projects?
It seems to me that we’re seeing more and more class projects aimed at this WikiProject but that the standard of work remains poor. A lot of time is being wasted trying to track down staff and students, not to mention trying to decide what to do with their gifts to us.
The Journal of Chemical Education (amongst others) already has several papers about getting classes to edit chemistry pages on Wikipedia. Having read a few of them I can’t say I’m terribly impressed:
Moy, Cheryl L.; Locke, Jonas R.; Coppola, Brian P.; McNeil, Anne J. (2010). "Improving Science Education and Understanding through Editing Wikipedia". Journal of Chemical Education. 87 (11): 1159–1162. doi:10.1021/ed100367v. ISSN0021-9584.
Martineau, Eric; Boisvert, Louise (2011). "Using Wikipedia To Develop Students' Critical Analysis Skills in the Undergraduate Chemistry Curriculum". Journal of Chemical Education. 88 (6): 769–771. doi:10.1021/ed100017k. ISSN0021-9584.
Walker, Martin A.; Li, Ye (2016). "Improving Information Literacy Skills through Learning To Use and Edit Wikipedia: A Chemistry Perspective". Journal of Chemical Education. 93 (3): 509–515. doi:10.1021/acs.jchemed.5b00525. ISSN0021-9584.
The focus of these guides is very much on the student experience and the opinion seems to be that so long as content is added with sufficient references then Wikipedia’s needs are met. The way things are described in the articles gives me the impression that the authors weren’t experienced editors at the time of writing.
McNeil et al do propose that articles be written in a sandbox and be checked by the course supervisor before being transferred to mainspace but mention this project only in passing.
Martineau et al cite and adopt the same approach but fail to mention community interaction at all.
Walker and Less is perhaps the best of the above papers but only because it talks in very general terms.
What I’m wondering is should we write a ChemEd paper about running class projects? We could include fairly detailed advice how to set things up and what to write (and what not to!) and how to engage with the community so that the students’ hard work is actually worthwhile. --Project Osprey (talk) 13:11, 24 March 2017 (UTC)[reply]
There is already some general writeups around. We probably need some more on how to choose topics in chemistry. The environment course classes seems to have trouble selecting suitable topics in particular. Perhaps we can have a prepared list of suitable requested topics. Or we could have proposed topics run past the project here first. Other wise we end up with essays or academic papers insted of encyclopedia entries. Other issues relate to WP:MEDRS, and NPOV (often because so few sources are used) and excessively technical writing. Other more general problems are already covered, eg copyright infringement, edit warring, verifyability. Some instructors actually end up with good results in other areas. I will ahve a look for the course advice. Graeme Bartlett (talk) 01:52, 25 March 2017 (UTC)[reply]
The problem is the focus on creating new articles when it should be clear most have have already been created, I would personally advise class projects to focus on fact-checking and content correction. This would be a better skills training for students than blindly copying other encyclopedia's V8rik (talk) 11:15, 25 March 2017 (UTC)[reply]
To my mind most of the problems we have stem from 3 issues:
Lack of communication: everyone knows that Wikipedia is community run but that somehow never translates to people trying to find the chemistry editing community. The lack of course-pages, preventing us from contacting these groups directly is related.
Wrong content: we want general information of a broad topic but we always seem to get detailed information on a narrow topic.
Conflicting desires: The students want to make a large body of work, that's clearly their own, and then add it in one massive edit. We don't work like that. This is probably the hardest point to fix, although sandboxes and use of articles for creation may help.
The existing literature doesn't address any of this. V8rik makes a valid point; the cleanup listing for WikiProject Chemistry (https://tools.wmflabs.org/bambots/cwb/bycat/Chemistry.html) provides a complete list of things that need checking, although I would strongly advise that we steer students away from contentious articles (e.g. PCB's). For my part I do think that new pages can still be created, particularly distinct small molecules ( here's a old list but if you turn the average bottle of shampoo around you'll find something that we don't list). What we would need to do would do is include explicit instructions on what to include and what not to. --Project Osprey (talk) 12:28, 25 March 2017 (UTC)[reply]
As they stand, the "aza" article is for when the nitrogen is anywhere (internal or terminal position of diene, or dienophile) and the "imine" article is specifically for when the nitrogen is the dienophile. But both are imine functional groups. The refs for the "imine" article only seem to use that term as part of phrases like "imine dienophile". Ahe only examples actually discussed at the "aza" article (after a generic scheme of the three possibilities) are ones with imine as the dienophile and that do not even procede by a classic Diels–Alder mechanism. So there is substantial overlap or unclear content scope, and one is missing content if one is to be a top-level with subarticles on specific variants. Apparently there is a lot to say about the imine-as-dienophile subtopic, so maybe the article on that topic should be given a more specific name? I'm open to suggestions for this or other solutions. DMacks (talk) 16:24, 16 April 2017 (UTC)[reply]
Here's a report from CAS. A lot of reviews mention aza-Diels-Alder (at least when the search term = Aza-Diels-Alder, zero hits for "Aza-Diels–Alder") and these two appear relevant, one new in a questionable venue, one old in a good journal. I looked at Boger's review hoping that he pointed to a super-classic example, but did not find one.
"Stereoselective Aza-Diels-Alder reactions" Rowland, Gerald B.; Rowland, Emily B.; Zhang, Qiang; Antilla, Jon C. Current Organic Chemistry (2006), volume 10, 981-1005.doi=10.2174/138527206777435463.
"Diels-Alder reactions of azadienes" Boger, Dale L. Tetrahedron (1983), volume 39, 2869-939. doi = 10.1016/S0040-4020(01)92154-4.
If I owned Wikipedia, the two articles would be merged and readers would be told of the diverse types of aza-DA including aza on the ene or the diene. --Smokefoot (talk) 18:31, 16 April 2017 (UTC)[reply]
Copyright issue with an image, can someone please quickly check two literature references?
Hi, I wonder if some editors more familiar with chemistry articles could take a look at Heptamethine dyes, this articles appears to me to be a promotion piece for one research group that is active in this area. It relies heavily on reference to one of their papers. I'm not sure it meets WP:GNG and could be worthy of AFD but I want to see what others here think. Thanks Aloneinthewild (talk) 11:28, 23 April 2017 (UTC)[reply]
I am not expert on the topic, but the article appears to be hype job of some narrow area. Indocyanine dyes are widely used in medicine (13535 hits), the vast majority (13212 hits) of citations involving Indocyanine green, for which we have a respectable article. Heptamethine dyes, the topic in question, is the subject of 40 hits, none of which are heavily cited. No review has been written. Aside from the tone of the article, a WP:COI aspect is indicated by one of the X-ray figures, which is sourced as "This is a photo of an xray overlaid with a heptamethine dye in mice. They have sent me an email allowing me to publish it under the heptamethine dyes section." My advice would be to take the article back to bare bones where it defines a heptamethine and makes brief mention of the currently cited literature. Probably some violations of WP:MEDRS. --Smokefoot (talk) 14:05, 23 April 2017 (UTC)[reply]
Notability of chemicals?
It's been awhile since I've checked into this topic, but how do folks here normally assess WP:GNG of a chemical? For the biology end of things we have WP:SPECIESOUTCOMES, but I haven't seen anything equivalent for chemicals. I'm currently figuring out what to do with 2-Decenedioic acid with the problem being that it really gets no mention in sources, and the only thing that really comes up are old primary journal articles that briefly mention it's found in royal jelly in lists or tables. Basically, not enough to warrant even the current unsourced sentence from a WP:WEIGHT perspective, and barely worth mention if at all at the royal jelly article. Would folks think this in an article for deletion territory, or there some other standard used for chemical stubs like this like having a CAS number to fill out the infobox at least? Kingofaces43 (talk) 05:05, 26 April 2017 (UTC)[reply]
What we have in that article is hardly worth having. But 2-Decenedioic acid appears to be a notable topic in that many independent authors have written on the topic, and been referenced by others. So we don't have the situation of one author pushing an idea that is not recognised by anyone else. There are also reviews: "The biological significance of ω-oxidation of fatty acids" by Yoshiro MIURA; and Contribution of of less chemistry focus: "Lipids in Honeybee (Apis mellifera) Royal Jelly to Health" Xing'an Li, Chaoqun Huang, and Yunbo Xue. And the artcle should reference SOME CARBOXYLIC ACIDS PRESENT IN ROYAL JELLY by William H. Brown, Robert J. Freure. It should definitely appear in the table in Dicarboxylic acid#Unsaturated dicarboxylic acids. added Graeme Bartlett (talk) 05:38, 26 April 2017 (UTC)[reply]
And having a CAS number is certainly not enough to warrant an article. We should be able to apply WP:GNG, but extend it to two different authors writing on the topic and not just one person who then references herself. I don't think that we want to be like species and say that if someone claims it exists, we can have an article on it. It gets even worse with fossils, as the evidence then is even more tenuous. Sometimes even if a chemical does not exist, it can have an article, eg NF5. The advice for students could also include what chemicals are worth writing about. Graeme Bartlett (talk) 05:45, 26 April 2017 (UTC)[reply]
Acetylide
Our acetylide defined this group as HC2-, but now someone changed it to C22-. The Goldbook says that it can be either, but with an electropositive metal attached:
https://goldbook.iupac.org/html/A/A00067.html).
Acetylides: "Compounds arising by replacement of one or both hydrogen atoms of acetylene (ethyne) by a metal or other cationic group. E.g. NaC≡CH monosodium acetylide. By extension, analogous compounds derived from terminal acetylenes, RC≡CH."
I propose that we accept IUPAC's definition, remove the chembox since the anions themselves are not covered (anyway such carbanions do not exist without a covalently attached metal). Comments are welcome. --Smokefoot (talk) 14:56, 29 April 2017 (UTC)[reply]
I indeed don't like covering ions as independent chemicals (though the anion can have sufficient notability). Just wondering, would one be able to make an ammonium or phosphonium acetylide (tetramethylammonium, tetrabutylphosphonium or the like)? --Dirk BeetstraTC16:29, 29 April 2017 (UTC)[reply]
OK, I'll probably proceed in removing the box. I also dont understand the point of a chemboxes for most ions.
Regarding the chemistry question, I dont think that one can make quat salts with highly basic anions, but I do not know the cut-off pKa. R4P+ forms phosphoranes with OR-, F-, and anything approaching a carbanion. R4N+ suffer Hofmann elimination even with hydroxide for R = Et or longer. R = Me resists degradation indicated by the fact that Me4N+F- is the unique quat fluoride that can been isolated in anhydrous state. --Smokefoot (talk) 17:27, 29 April 2017 (UTC)[reply]
Bis(tetrabutylammonium)acetylide appears to be known.[1] Trialkylammonium acetylides are believed to exist in equilibrium as transient intermediates in the Cacchi coupling reaction and Sonogashira–Hagihara coupling reaction.[2] An extensive attempt to synthesize tetramethyl or guanidinyl acetylides (I *think* they were aiming for mono not bis) did not succeed.[3]DMacks (talk) 03:11, 30 April 2017 (UTC)[reply]
References
^Used on page 20 of Woltermann, Christopher J. (1996). Part 1: Studies of Synthesis of Mono- and Dinitroacetylenes, Acetylenic Nitrites and Nitrosoketenes (Thesis). The Ohio State University.
^Bruckner, Reinhard (2001). "13.3.4 Alkenylation and Arylation of Copper Acetylides". Advanced Organic Chemistry: Reaction Mechanisms. Academic Press. pp. 535–538.
SciFinder couldn't find any tetraalkylammonium acetylides or tetraalkylphosphonium acetylides. Lots of false-positives though (tetraalkylammonium/phosphonium salt of other anionic sites in alkyne-containing molecules). DMacks (talk) 20:46, 30 April 2017 (UTC)[reply]
I think this may have been my fault; my reasoning was while the page defined acetylide as HC2-Category:Acetylides contains only examples of MC≡CM species. To be frank the page needs a through re-write, the chemistries of HC2-, RC2- and MC≡CM are all jumbled together.--Project Osprey (talk) 22:03, 29 April 2017 (UTC)[reply]
At one time I duplicated the chembox, to make "ionbox" but it was not really a good idea. I think we can use for chembox for ions, as long as the article is just about the ion. If it is about a family of compounds, then chemboxes are not the right thing to use. A table of info can show information for several non-notable substances in the family. Graeme Bartlett (talk) 07:16, 30 April 2017 (UTC)[reply]
If you have time, can someone please take a look at Cyclic microcellular foaming? It is looks a little bit like spam to me.
The images are nice, the article is on a "minor" journal, cited 13 times in 4 years I guess the concept can be cited in some other article but an entire wikipedia article describing the publication is IMHO excessive. It is not my field, if someone else has the will and expertise (s)he can recycle and downsize the information (especially some of the images, they seem nice) somewhere else, and than propose a deletion? I am just saying, I don't know how to evaluate this field.
Is that really the correct spelling, with one l instead of two? Clayden, Greeves, and Warren (2nd ed.) have it with two l's on p. 1076. Double sharp (talk) 15:22, 2 May 2017 (UTC)[reply]
That is a recurring question. Here're the data from Chem Abs:
"metallation" → references (817) of which 51 are reviews, only one well cited (239 cites)
"metalation" → references (16547) of which 876 are reviews, at least 10 of which are cited >500x each, including those by Snieckus, Fu, van Koten, and other leading scholars. Here is one example in the title: "Directed ortho metalation. Tertiary amide and O-carbamate directors in synthetic strategies for polysubstituted aromatics" Snieckus, Victor
Thanks; good to know! Perhaps we should mention a little bit about the variant spellings in the article, so that the question recurs less often? Double sharp (talk) 23:03, 2 May 2017 (UTC)[reply]
OK I just changes all of them that were not part of an article's title
ZnCl for what I am guessing is meant to be zinc chloride
two species with zinc centres shown with negative formal charges, Zn2−
And in addition:
issues with charge balance
it appears that the deprotonated 2,2'-dihydroxybiphenyl and tert-butyl ligands on the zinc centre appear to disappear to be replaced with methyl groups (I know this is not the intended meaning, but to a non-chemist it could be confusing).
where did the H's on the 2,2'-dihydroxybihenyl go when it became an anion
tert should be italicised, so t-Bu or more commonly tBu, I think, rather than t-Bu
it appears that the MgCl 2 has a charge, as MgCl+ 2
A 2M+ , which I think is meant to be a Cu+ and a Li+ , and makes me wonder why the MgCl 2 (with or without charge) vanishes but the Li+ remains and the CN− and Br− don't appear either like the cations do
I'm wondering if there are other things editors want to suggest be changed, and whether V8rik or another editor can provide a replacement. Thanks. EdChem (talk) 10:20, 3 May 2017 (UTC)[reply]
Can we delete the chembox in Nascent_hydrogen ? This is not a chemical compound but a chemical concept for reactive hydrogen which is now deprecated. Having a chembox with data for hydrogen creates confusion. Snipre (talk) 08:58, 5 May 2017 (UTC)[reply]
Although one of the most enthusiastic deletionists, I wonder if we shouldn't keep but make sure that its tone is disparaging. We have a full article on Flat Earth. Someone is going to create this thing again, so we might as well have something sitting there that makes clear that it is a junk concept. To keep the conversation going, I removed most of the article. Feel free to revert or redo my action. --Smokefoot (talk) 10:35, 5 May 2017 (UTC)[reply]
My concern was just about the chembox which was filled with data and identifiers for molecular hydrogen. But I think the article should be kept: we just have to focus on the concept and not on the chemical. Snipre (talk) 11:09, 5 May 2017 (UTC)[reply]
I agree completely that the article should be kept, but needs to make absolutely clear that the concept is deprecated. Changes are needed to the article Nascent state (chemistry), too. Smokefoot's trimming of the article is drastic but justified. I'm looking into seeing what I can add that is in line with the actual topic. EdChem (talk) 11:51, 5 May 2017 (UTC)[reply]
I've started adding some history. Searching in Google books, however, there are some decidedly odd recent book sources that take nascent hydrogen seriously like: [6] and [7] and [8] – on this last one, I wonder if the term has come to have a meaning in engineering? EdChem (talk) 13:17, 5 May 2017 (UTC)[reply]
@EdChem: I think one could conclude that that last text took a pragmatic approach to simplifying the explanation chemistry of hydrogen embrittlement at the cost of accuracy. Defensible, maybe, given the potential repercussions of improper material selection of alloys for high-temperature hydrogen service, but I wouldn't infer any special meaning in engineering at large based on it. VQuakr (talk) 23:07, 6 May 2017 (UTC)[reply]
Looking at the two references you have you'd think the term has meaning in passing official chemistry tests in India. The kids over there are not to be envied. (I've seen the term in the context of the Langmuir torch. 158.93.6.11 (talk) 22:48, 6 May 2017 (UTC)[reply]
The history of the concept is recapitulated in Bull. Hist. Chem.1990,6, 26-36, online here [9] and here [10]. That review should allow to get rid of most of the references to primary literature. 158.93.6.11 (talk) 20:25, 5 May 2017 (UTC)[reply]
Meh. The two subjects together are never likely to need to be separate for purely length reasons, but the focus of Nascent hydrogen is currently more on, well, hydrogen. I am unconvinced that it is editorially favorable to merge them. VQuakr (talk) 18:28, 7 May 2017 (UTC)[reply]
I concur with VQuakr, the idea of the nascent state is applied to substances other than hydrogen, the Bull. Hist. Chem. paper mentioned above talks of nascent oxygen and nascent chlorine, IIRC. I suspect hydrogen is the only element that is due a separate "nascent ELEMENT" article, but I do think the content is better separating the idea of the state from the specific example of hydrogen. EdChem (talk) 17:32, 14 May 2017 (UTC)[reply]
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)[reply]
@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)}}.
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).
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)[reply]
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)[reply]
BR vs WBR separator usage in Chembox
Hi, there were many occurrences of single IUPAC name (IUPACName=...) split by <br> (in order to pre-split the long name to fit it in the box obviously), however the side-effect was that it was interpreted as multiple IUPAC names in the Chembox. So I took the initiative of replacing the <br>'s that were meant such way, to <wbr>'s, according to WP:LINEBREAK, and because
at least two major web browser that I was checking, were auto-splitting long words containing hyphens without problems,
Wikipedia is served as html(5) doctype, so the <wbr> usage should be without problems as well.
Great edits, that's the tag I was searching for all those years. I hope it does not copy/paste and that you had an eye for true newlines (for starting a new name). -DePiep (talk) 13:53, 8 May 2017 (UTC)[reply]
Of course I had to be careful, and I did try hard not to brute replace all BR's (e.g. this edit). That's also why I did not yet try to learn to write editing bots. —Mykhal (talk) 19:30, 8 May 2017 (UTC)[reply]
I don't know what AWB is. I have used google search query: "iupac names" -"iupac name" site:en.wikipedia.org SMILES OR "InChI", so I got many false positives. But I think I have sifted through and edited all resulting pages. —Mykhal (talk) 18:48, 9 May 2017 (UTC)[reply]
The "false positives" are cases when multiple names are used, and cannot be distinguished reliably from those artificially inserted possible word breaks without advanced artificial intelligence, like human brains. It can be done unreliably with some assumptions e.g. that a name beginning is /(\d+(,\d+)*-)?[A-Z]\w/ after BR —Mykhal (talk) 20:15, 14 May 2017 (UTC)[reply]
Moving identifiers out of the infobox: WP:MED in action
Infoboxes {{Chembox}} and {{Drugbox}} are long with much data that is maybe not in the best place there. Over at WP:MEDICINE a similar problem is approached in an RfC, by creating a separate "Resources" box way below on the article page. Could be inspiring. -DePiep (talk) 15:45, 8 May 2017 (UTC)[reply]
TBH, I think the identifiers should not be placed so highly, since they are all external links (while I do appreciate the "jump to more data" opinion). --Izno (talk) 16:28, 8 May 2017 (UTC)[reply]
There is nothing against external links in infoboxes, many carry them (though we do linkfarm, relatively speaking). I do have sympathy for the 'authority control'-type of linking as well, which is not a bad option. It is just .. I use these links sometimes to verify whether the Wikipedia numbers are OK (I don't always trust Wikipedia) .. gets a bit of a down-and-back-up action if they are at the bottom. --Dirk BeetstraTC17:15, 8 May 2017 (UTC)[reply]
A wp:infobox really should be a summary of the article, and we in chemistry can add the melting and boiling points reasonably. But those coded-ID external links are not really lead-infobox level info. Quite telling: by Wikipedia design, the infobox is the first show especially in mobile view (see aspirin in aspirin (mobile view)). Not every reader has preferences like Dirk, Dirk ;-). IMO we really could use a section 'data sheet' for chemicals. -DePiep (talk) 20:43, 8 May 2017 (UTC)[reply]
Identifiers such as CAS numbers are lead level material and absolutely belong in the infobox. Many readers, myself included, have a preference like Dirk's. The problem with the mobile view is that that portions of the navbox cannot be collapsed. I have made a proposal to fix that here. Boghog (talk) 03:04, 9 May 2017 (UTC)[reply]
The CAS number for infobox is not the best example (it's the easiest 'yes'). Same for melting point. But issues arrive with the dozens of other identifiers and properties. These are properties we surely expect in a 'datapage' section, but not in the lede/infobox top.
About collapsing infobox sections (never in mobile view): there is a reason for that omission. It has to do with webpage design & usage (note: not just Wikipedia page design then). In short: if it is unimportant enough to collapse&hide, then it need not be there. And I can understand your "Dirk's" preferences, but we editors are not representative for our readers. -DePiep (talk) 21:32, 9 May 2017 (UTC)[reply]
I understand that we are not (necessarily) representative for our readers. That is why the WP:MED decision surprises me, the editors there made the decision to move the identifiers to the bottom of the article, based on their preferences within the project. Then when the exact placement was questioned (where at the bottom), a global discussion was started. I, who is more a reader of medical articles, suggested to .. keep them in the infobox.
I also go with Boghog's additional argument that some of the identifiers are lead-level material. And please don't let us get the idea to move all but three to the bottom of the page. --Dirk BeetstraTC03:08, 10 May 2017 (UTC)[reply]
The assertion that collapsed navboxes should not be used in mobile is nonsense. Many, many mobile phone apps make effective use of collapsed information that can quickly be uncollapsed to reveal more detail. This is a glaring omission in the Wikipedia mobile view that needs to be rectified. I am only proposing that the infobox be collapsed in the mobile view, not in the desktop view. Furthermore the problem with navboxes in mobile view is not only due to the identifiers section, but other sections as well. Because of their large size, infoboxes overwhelm small screens. One has to scroll down quite a ways to get to the lead. On the desktop, a large infobox is much less of an issue. This is especially true of articles with a long table of contents where the navbox can effectively use otherwise wasted space to the left of the table of contents. Boghog (talk) 05:09, 10 May 2017 (UTC)[reply]
Sections of articles starting with the second section in the Mobile view are collapsed. Why is it OK to collapse article sections and not navbox sections? Boghog (talk) 10:06, 11 May 2017 (UTC)[reply]
My take: section titles this way are the TOC. Is the main navigation for a page. Collapsing parts of a box does not fit this reader perception. I guess it is undesired to use the mobile screen with more than a few zoom-levels, because the reader might loose overview ('where am I?'). Assuming our page-designers do not want to add that show/hide option, my suggestion nicely does use-section-to-collapse by creating a section "==Data sheet==". Also fits with my idea that not all data is important enough for the top infobox. -DePiep (talk) 10:39, 11 May 2017 (UTC)[reply]
Yes, the section titles in the mobile view are the TOC. For consistency, it would also make sense to collapse all the sections of the infobox. The section titles within the infobox would then provide navagation within the infobox. Even if one moved all the identifiers out of the infobox (which I think is a really bad idea), many infoboxes would still overwhelm the lead in the mobile view. Allowing the option of collapsing sections of the navbox fixes this problem. One could even make the case that infobox sections should be collapsed by default. Boghog (talk) 11:18, 11 May 2017 (UTC)[reply]
EU classification (DSD) will soon cease to be in force
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
Hi. I have looked a few times within WP for content discussing industrial production of chemicals and where precursors come from. What has led me there are edits like this that pretty clearly derive from chemophobia.. with which I did this, btw).
I have looked a few times for sourcing to add content to Azo compound about how petrochemicals are used as starter stock (or I guess article-wise precursors) for industrial production and what goes on afterwards... practical nuts and bolts stuff that anybody could understand, including the high-level economics of it, but not found anything useful. Would be great if somebody who knows the literature could add content about that... with respect to azo dyes in general but everywhere, really. We often lack this kind of concrete content about how things are actually made and why they are made that way. Please consider! Thx Jytdog (talk) 17:24, 15 May 2017 (UTC)[reply]
It would be great if such information were readily available, but often this information is held as trade secrets by the manufacturers. Nevertheless, there seem to be several promising sources, for example:
Weissermel, Klaus; Arpe, Hans-Jürgen (2003). Industrial Organic Chemistry Important Raw Materials and Intermediates (3rd ed.). Weinheim: Wiley-VCH. ISBN978-3-527-61459-2. {{cite book}}: Unknown parameter |name-list-format= ignored (|name-list-style= suggested) (help)Boghog (talk) 17:52, 15 May 2017 (UTC)[reply]
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.
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)[reply]
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/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.
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)[reply]
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)[reply]
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)[reply]
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
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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?
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)[reply]
Done There wasn't much salvageable, even -oic acid if it were to remain should have been ripped apart to actually focus on the topic such as it was (WP:NOTTEXTBOOK). DMacks (talk) 21:36, 18 March 2017 (UTC)
accepted. Graeme Bartlett (talk) 04:18, 17 May 2017 (UTC)
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