Wikipedia talk:WikiProject Chemistry/Archive 45
 | This is an archive of past discussions on Wikipedia:WikiProject Chemistry. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
| Archive 40 | ← | Archive 43 | Archive 44 | Archive 45 | Archive 46 | Archive 47 | → | Archive 50 |
Could someone from the Project take a look at this? It is beyond my knowledge of chemistry. Looks good with the possible exception of the article name, not clear that the term "Early transition" applies, but otherwise looks good and referenced.Naraht (talk) 15:49, 27 March 2018 (UTC)
- @Naraht: The article should be blended with Pincer ligand, which is the same topic. Some redirects are needed and help with referencing.--Smokefoot (talk) 16:04, 27 March 2018 (UTC)
- @Smokefoot: Blended is probably the best term, since the references on the Draft article appears to be better than the ones at Pincer ligand. I'll reject gently.Naraht (talk) 16:08, 27 March 2018 (UTC)
- I should be able to do the blending because there is good stuff in the abandoned article. Thanks again for reaching out to the Chem project.--Smokefoot (talk) 16:57, 27 March 2018 (UTC)
- @Smokefoot: Blended is probably the best term, since the references on the Draft article appears to be better than the ones at Pincer ligand. I'll reject gently.Naraht (talk) 16:08, 27 March 2018 (UTC)
Can someone with a bit more specialist knowledge than me check out this new article? It's a bit abstruse and weirdly organised and the fact that the page creator was reverted for vandalism shortly before publishing it makes me concerned about its quality. Reminds me of some of those articles created as a test of adding content to Wikipedia a while back. Blythwood (talk) 22:26, 27 March 2018 (UTC)
- It is wordy and not very good but we will salvage, especially since this student is determined to get his/her article. They seem to get graded based on the number of words. The main points were already covered in metallacycle, where I should have thought to create more redirects.--Smokefoot (talk) 00:54, 28 March 2018 (UTC)
- This is indeed a worthy subject, they are an important intermediate and one could argue to write it as a resonance structure of a metal-di-olefin-adducts. I'll have a look, time permitting. --Dirk Beetstra T C 04:11, 28 March 2018 (UTC)
User:Zakblade2000
This user Zakblade2000 (talk · contribs) has been creating useless, IMHO, categories (e.g. Category:Isopropyl compounds, Category:Trichloromethyl compounds, Category:Gases with color) and then populating them. This user seems to have a history of doing chemical categorizations that are in IMHO not that helpful even if the categories themselves are somewhat useful. Anyways, I am not aware of any guidelines or policies on chemical categorization, but maybe we have something? Does anyone else think this user is doing more harm than good with these types of edits? Should anything be done?Yilloslime TC 20:45, 29 March 2018 (UTC)
- Yes, I tend to agree that many of the categories are not necessarily helpful. But adding them keeps an editor busy, and that stuff can be revised or removed easily.--Smokefoot (talk) 12:48, 1 April 2018 (UTC)
The recent poisoning of a spy here in the UK is being linked to Russian Novichok chemical weapon agents. I don't know how big this is internationally but it's getting plenty of local coverage, as you would expect. Novichok agent has seen over 100 edits in the last 24 hrs by a range of characters - I would suggest that a temporary auto-confirm block might be an idea. Chemical weapons are unfortunately our area but with this being politically sensitive I'd be doubly careful about what sources we use.--Project Osprey (talk) 08:49, 13 March 2018 (UTC)
- Autoconfirm protected for two weeks initially, it's not vandalism on the whole, but unsourced additions to a high profile and sensitive topic Jimfbleak - talk to me? 12:21, 13 March 2018 (UTC)
- There seems to have been some unexpected fallout over at organophosphate, the current lead is certainly quite stark.--Project Osprey (talk) 11:45, 4 April 2018 (UTC)
Facto Post – Issue 11 – 9 April 2018
Facto Post – Issue 11 – 9 April 2018
 The 100 Skins of the OnionOpen Citations Month, with its eminently guessable hashtag, is upon us. We should be utterly grateful that in the past 12 months, so much data on which papers cite which other papers has been made open, and that Wikidata is playing its part in hosting it as "cites" statements. At the time of writing, there are 15.3M Wikidata items that can do that. Pulling back to look at open access papers in the large, though, there is is less reason for celebration. Access in theory does not yet equate to practical access. A recent LSE IMPACT blogpost puts that issue down to "heterogeneity". A useful euphemism to save us from thinking that the whole concept doesn't fall into the realm of the oxymoron. Some home truths: aggregation is not content management, if it falls short on reusability. The PDF file format is wedded to how humans read documents, not how machines ingest them. The salami-slicer is our friend in the current downloading of open access papers, but for a better metaphor, think about skinning an onion, laboriously, 100 times with diminishing returns. There are of the order of 100 major publisher sites hosting open access papers, and the predominant offer there is still a PDF.  From the discoverability angle, Wikidata's bibliographic resources combined with the SPARQL query are superior in principle, by far, to existing keyword searches run over papers. Open access content should be managed into consistent HTML, something that is currently strenuous. The good news, such as it is, would be that much of it is already in XML. The organisational problem of removing further skins from the onion, with sensible prioritisation, is certainly not insuperable. The CORE group (the bloggers in the LSE posting) has some answers, but actually not all that is needed for the text and data mining purposes they highlight. The long tail, or in other words the onion heart when it has become fiddly beyond patience to skin, does call for a pis aller. But the real knack is to do more between the XML and the heart. Links
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Periodic table
The articles Chemistry, Chemical element, and Periodic table have a periodic table on their page. However, each article uses a different file for their periodic table, Chemistry uses Periodic table (polyatomic).svg, Chemical element uses Periodic Table Chart.png, and Periodic table uses Simple Periodic Table Chart-en.svg. For consistency reasons, can you please edit each of the pages so that they include the same file for their periodic table? I do not care which file is used for each of the pages. 2601:183:101:58D0:E009:F9F6:98C8:AA7 (talk) 22:17, 23 April 2018 (UTC)
- I disagree. First, but least important, having three probably means that three wikipedians have photos on the site. But more importantly, I think people need to be clear that there is not one periodic table but a host of different ways of displaying it. In fact I think the three you describe are too alike. I think we should have a more diverse set of images. --Bduke (Discussion) 01:08, 24 April 2018 (UTC)
- I agree with IP, these graphs should be the same or at least similar. It is true as Bduke says the PT can take many forms, both in graphical and editorial choices and in scientifical statements made. However, we at enwiki, from project WP:ELEMENTS (talk), try to be consistent over all graphs shown. For example, the constitution of group 3 (which elements are in there?) is currently under scientific debate. For now WP:ELEMENTS has chosen the most well-sourced version, and the other options are described in appropriate articles (like here). Graphically, this group 3-statement is shown as a "column 3 = Sc/Y/La/Ac and other Lactanides, actinides next to that column - possibly using asterisk placeholders". This is or should be the same in all out periodic tables for consistency. This way, all looks and links describe the same situation.
- As for the three PT's listed here: indeed, two are outdated. I will replace them (the
one at Periodic tablesvg version is leading). - DePiep (talk) 07:37, 24 April 2018 (UTC) ch: svg version is leading
Opinions welcome on Fischer projections being added
User:Patchgood is adding a lot of artwork to articles on biochemically significant compounds. I don't like the artwork for the following reasons: the presentations require specialized knowledge to understand, the contributions may be promoting a commercial vendor, and the renderings are not great. But maybe I am too picky or am missing the message. Example below:
. --Smokefoot (talk) 02:23, 24 April 2018 (UTC)
- I agree that these "polygonal model" diagrams are too nonstandard to add any encyclopediac value for our readers. DMacks (talk) 08:15, 24 April 2018 (UTC)
- Indeed, please remove those. This is the first time I see it (well, I am not a biochemist), and require more knowledge to understand than just the at-linkage on the left. A high-school student should be able to understand the linkage, and everyone with more knowledge would understand the chirality of the model. The right side .. if you give me only that I would struggle. --Dirk Beetstra T C 09:18, 24 April 2018 (UTC)
- What a strange diagram. I've never seen it before (though the representation of phosphate as an encircled "P" is sometimes used as shorthand). The model may be a novel way of representing the structures, but I don't quite see the utility. Perhaps Patchgood would be willing to contribute a separate article about the so-called polygonal model, and establish notability. ―Biochemistry🙴❤ 11:26, 24 April 2018 (UTC)
- Draft:Polygonal model was declined last December at AfC. DMacks (talk) 14:55, 24 April 2018 (UTC)
- @Smokefoot: I agree remove them as per stated reasons, I wouldn't be surprised if he is the author of the paper he references...EvilxFish (talk) 13:59, 24 April 2018 (UTC)
- Should we also consider reporting this guy he is clearly just spam editing? EvilxFish (talk) 14:09, 24 April 2018 (UTC)
- Echo Biochemistry&Love word by word.And, we're definitely looking at a case of probable COI spamming. ~ Winged BladesGodric 14:15, 24 April 2018 (UTC)
- @Winged Blades of Godric: I don't really know how to report spam :S, Please could you do it or point me in the right direction. Should we begin reverting his edits? EvilxFish (talk) 14:24, 24 April 2018 (UTC)
Patchgood (talk) 14:51, 24 April 2018 (UTC) I appreciate the concern of the adding the images in Wikipedia, since it is very important struggle to high-level articles in general. As a medical student and after doing a professorship of Biochemistry since 1986, I have experienced a crescent devaluation of the molecular structure teaching of biochemistry. This can be shown by the great quantity of information and the natural attention to the understanding of metabolism, regulation, states of feeding-starvation made available by the current methods. It is clear that the memorization of such biomolecules is very tough, often leading to forgetfulness in the short term. I observed that the introduction of a graphical way to represent the biomolecules really help the understanding of the metabolic pathways in students, considering its related chemical changes and such, facilitating the retention of structure details even in the Fischer model, since it is very easy to interchange the codification between models. The cited publication on “Biochemistry and Molecular Biology Education” explains better these interchanging conditions, as well as the experience in using the polygonal model in several graduate students classes from different courses. There is absolutely no commercial interest in exploring this model since the knowledge was made freely available through its publication in the indexed journal of the area of education in biochemistry. I am collaborating with professionals who teach organic chemistry to high-school students and this experience is showing that this model is a very promising approach. I agree that it is a new knowledge, but it is already published and it’s undergoing continuous improvements in order to provide a better understanding of an area tough to be explored in classrooms. The quality of the artwork can be improved using other programs that allow sizing the image several times, but since this is not the present goal, we are using Python for drawing the molecules in a GNU/Linux environment. The resolution is good for the size it was applied to, and journals accept it for publications. As User:Biochemistry&Love suggested, we intend to submit a new entry as “polygonal model” in Wikipedia for explaining more details concerning the way to represent these molecules from Fischer projections, furnishing examples of materials for training, helping the reader to became more familiar to polygonal model, and for relating experiences with students using such approach. Anyway, all such information is present in the reference cited in the different articles which were included the molecule represented in the polygonal model. I would like to emphasize that all procedures are in accordance with the goals and terms of use of Wikipedia (see https://wikimediafoundation.org/wiki/Terms_of_Use/en). In such direction, we collected and developed educational content and either we publish it under a free license or dedicate it to the public domain, disseminating the content effectively and globally, free of charge. Moreover, it was respected all conditions listed in the Wikipedia rules, as the responsibility of our edits, civility, lawful behavior including no violation of copyright, and no harm of the technology infrastructure of Wikipedia. Finally, we follow all terms of use and policies of Wikipedia, and license freely our contributions, with no professional advice.
- @Patchgood: Though I wish you the best of luck in your work you must acknowledge Wikipedia is not the appropriate platform for new ideas and at the time of writing your ideas are neither widely accepted nor used in reliable secondary sources as such your images should be removed. EvilxFish (talk) 15:53, 24 April 2018 (UTC)
- On top of that you have already attempted to create an article on the "polygon model" which was rejected and have a clear conflict of interest. EvilxFish (talk) 15:57, 24 April 2018 (UTC)
- Your technical skill and dedication is truly admirable, but Wikipedia is not a suitable forum for promoting new ways to report well-established knowledge. Good luck with your venture.--Smokefoot (talk) 17:12, 24 April 2018 (UTC)
- @Patchgood: Thank you for your reply. Let me address a couple key points here: (1) your research is primary literature, and WP relies upon independent, secondary/tertiary literature; (2) although you may lack commercial interests in the model, you must know as an academician that your worth is improved by the dissemination of your ideas, ergo presenting a COI (even if a non-directly financial one). If your model becomes the standard in the future, then it will be worth including; until then, it's probably too soon to make such sweeping changes. I would recommend focusing on demonstrating the notability of your draft on the model in the meantime, or directing your expertise elsewhere on improving unrelated pages. ―Biochemistry🙴❤ 17:17, 24 April 2018 (UTC)
opinions wanted on quality of section in MD article
Hi all, I have started a discussion here on rewriting the examples of applications section in the MD article. It references mainly primary literature and I think it should be more general. Please let me know what you think. EvilxFish (talk) 08:52, 26 April 2018 (UTC)
Natural materials
Is this article necessary? Natural materials--MaoGo (talk) 12:47, 2 May 2018 (UTC)
- It is a good topic, but the contents could do with some work. Graeme Bartlett (talk) 12:53, 2 May 2018 (UTC)
- I agree with Graeme. A bit of overlap with natural product. But since the product article deals primarily with purified organic substances isolated from natural sources, I think the materials article is worth while. The two should cross reference each other. Boghog (talk) 13:15, 2 May 2018 (UTC)
- I guess that I disagree somewhat. Any article on "topic x" almost must start with a general reference that shows that "topic x" is a defined term. Otherwise editors just dream up topics. Let's see the book(s) entitled "Natural Materials".--Smokefoot (talk) 13:50, 2 May 2018 (UTC)
- There is in fact at least one: Natural_material#Further_reading. Boghog (talk) 14:18, 2 May 2018 (UTC)
- Oh, I missed that. Maybe that ref should be in the regular ref list. Thanks, --Smokefoot (talk) 14:20, 2 May 2018 (UTC)
- I guess that I disagree somewhat. Any article on "topic x" almost must start with a general reference that shows that "topic x" is a defined term. Otherwise editors just dream up topics. Let's see the book(s) entitled "Natural Materials".--Smokefoot (talk) 13:50, 2 May 2018 (UTC)
- I agree with Graeme. A bit of overlap with natural product. But since the product article deals primarily with purified organic substances isolated from natural sources, I think the materials article is worth while. The two should cross reference each other. Boghog (talk) 13:15, 2 May 2018 (UTC)
HTML errors in chemistry articles
The wikitext parser is going to change in June, and any page with an error may display strangely. I'm going through Special:LintErrors, and I've found some high-priority errors in articles tagged by this WikiProject.
What's needed right now is for someone to click these links and compare the side-by-side preview of the two parsers. If the "New" page looks okay, then something's maybe technically wrong with the HTML, but there's no immediate worry. If that column looks wrong, then it should be fixed.
There is just one "deletable table" error for this project, in https://en.wiki.x.io/wiki/List_of_cocaine_analogues?action=parsermigration-edit&lintid=81613296 If you want to know more about how to fix these pages, then see mw:Help:Extension:Linter/deletable-table-tag. When you click that link and scroll down to the wikitext, you'll see some highlighting that shows where the lint error is; it's in a nested table. It appears to have two starts to the table (maybe to add two different styling classes?). Removing either of those would probably solve the problem.
This longer list is "misnested tags". See mw:Help:Extension:Linter/html5-misnesting for more information. The highlighting for the first link indicates that the problem for that article is related to a <span id=SIL> tag. There is no closing tag (an error made repeatedly in this article), and that's presumably the source of the error.
| url | more_info |
|---|---|
| https://en.wiki.x.io/wiki/Nonmetal?action=parsermigration-edit&lintid=93042779 | {"name":"span","templateInfo":{"multiPartTemplateBlock":true}} much work required to fix non-standard referencing |
Note that the highlighting from the lintid code won't work reliably after the article has been edited, so for pages with multiple errors, it's best to try to fix them all at once. For more help, you can ask questions at Wikipedia talk:Linter. Good luck, Whatamidoing (WMF) (talk) 18:31, 4 May 2018 (UTC)
- I took care of a batch, as well as the single table error. --Izno (talk) 20:23, 4 May 2018 (UTC)
- If any of these problems arises from {{Chembox}} or {{Infobox drug}} (I maintain), please notify me. I can not research the lint-issues myself. - DePiep (talk) 21:34, 4 May 2018 (UTC)
- No problems identified in chembox or drug box. I have fixed and removed some easy ones to repair. Two need a rework of references, and another two I cannot see what is wrong. Graeme Bartlett (talk) 00:14, 5 May 2018 (UTC)
- {{Nowrap}} is a common offender. You can either remove the nowrap, make the nowrap a block by using something like
<div class="nowrap">, or ensuring everything inside such a block is all on one line. I removed the nowrap in the case of one. This is also the offender in the Ziryab article (and could be fixed in the infobox by the same or by fixing the line break in the article; I elect for the latter).
The reference one (for both) was a few missing / in a pair of spans. --Izno (talk) 05:35, 5 May 2018 (UTC)
- {{Nowrap}} is a common offender. You can either remove the nowrap, make the nowrap a block by using something like
- No problems identified in chembox or drug box. I have fixed and removed some easy ones to repair. Two need a rework of references, and another two I cannot see what is wrong. Graeme Bartlett (talk) 00:14, 5 May 2018 (UTC)
- If any of these problems arises from {{Chembox}} or {{Infobox drug}} (I maintain), please notify me. I can not research the lint-issues myself. - DePiep (talk) 21:34, 4 May 2018 (UTC)
Imidogen, nitrogen monohydride, nitrene
We probably should seek some consensus on these overlapping articles. I would be glad to do this, shifting them to a greater reliance on secondary and tertiary references. I would put a merger banner on these articles after I hear from others.
- "Imidogen (systematically named λ1-azane and hydridonitrogen), also called aminylene or nitrene, is an inorganic compound with the chemical formula NH••..."
- "In chemistry, a nitrene (R–N:) is the nitrogen analogue of a carbene..."
- "Nitrogen monohydride (NH) is a simple compound that has been detected in interstellar space..."
One approach might be to have one article on NH that acknowledges the existence of NR and another article on nitrene insertion chemistry. But then, maybe just one master article.--Smokefoot (talk) 13:50, 9 May 2018 (UTC)
- I have the strong feeling that Imidogen and Nitrogen monohydride are talking about exactly the same thing, whereas a nitrene is different from that. I would therefore merge 1 and 3, and keep 2 separate with a mention that imidogen is the simplest one, and pointing to any that are of particular chemical interest (if any). —Dirk Beetstra T C 17:38, 9 May 2018 (UTC)
- Imidogen and Nitrogen monohydride are the same. But a nitrene is a different class of substances. So I am agreeing with Beetstra for action. Graeme Bartlett (talk) 23:08, 9 May 2018 (UTC)
I have made it so:
articles that you have been involved in editing—Nitrogen monohydride and Imidogen—have been proposed for merging with another article. If you are interested, please participate in the merger discussion. Thank you. --Dirk Beetstra T C 06:53, 10 May 2018 (UTC)
Orientation of structure diagrams?
I'm looking at the two structure diagrams in Ornithine:
It took me a while to get oriented because they're backwards with respect to each other. One has the c-terminal end on the left, the other has it on the right. They may structurally equivalent, but it seems like it would be better to present them both in the same orientation, so it's easier to see what corresponds to what. Is there any kind of standard, either in the real world, or in WP style, that talks about this? -- RoySmith (talk) 13:42, 10 May 2018 (UTC)
- Good catch, but the problem - stereochemical consistency as well as drawing perspective - is pervasive in Wiki-Chemistry. It's not that we are sloppy, just that the articles are a mish-mash accumulated over years by many editors of diverse skills, software access, and ways of looking at things. We are still in early stages.--Smokefoot (talk) 14:12, 10 May 2018 (UTC)
- On a slightly different note, I'm used to thinking about amino acids as the N-C-COOH backbone being the main structure, with the R group stuck on the side. The way the structure diagram is drawn, it lays the molecule out with the longest C chain as the main visual element. It's not wrong, but it's also not the way I think about these molecules, so it was another mental stumbling block to getting the diagram oriented in my mind. -- RoySmith (talk) 15:19, 10 May 2018 (UTC)
- The same molecule might have a different preferred orientation depending on the context. Being consistent in a chemical reaction, being consistent in an article, being consistent with how a certain discipline does things, and being consistent with how another relevant discipline does things...that's a hopeless deadlock in many cases. It's not really wiki-specific or persistence of old images from prior to a change of standards. It's no problem for commons to host high-quality images of the same molecule in diverse orientations or styles. Best we can do is do whatever is most appropriate in each situation for the encyclopediac point trying to be made. So for infobox multiple images, they should all be in the same orientation. For a table of amino acids, they should all have the R group in the same position, and a short peptide probably with N-C-CO as backbone (and therefore individual amino acids likewise when mutations being discussed). DMacks (talk) 16:13, 10 May 2018 (UTC)
- Two related problems are that most editors draw most molecules from scratch rather than looking at commons and we often can't even get editors (sometimes even long-term ones) to follow basic MOS (especially difficult coordinating commons as a multisite central repository, but even true on en.wp-centric). A slightly related problem is that commons images are often not fully categorized for ease of searching. For your example, we have commons:Category:Ornithine, but File:Ornithine ball-and-stick.png
isn'twasn't in it. DMacks (talk) 16:18, 10 May 2018 (UTC)- Considering the amount of low-quality and/or chemically incorrect (either in fact, or mismatch with filename/description), I don't fully blame en.wp editors for not looking. But everyone wins when images on commons get re-used and mistakes there fixed. Let me know if anyone needs help working on commons. DMacks (talk) 16:35, 10 May 2018 (UTC)
- Two related problems are that most editors draw most molecules from scratch rather than looking at commons and we often can't even get editors (sometimes even long-term ones) to follow basic MOS (especially difficult coordinating commons as a multisite central repository, but even true on en.wp-centric). A slightly related problem is that commons images are often not fully categorized for ease of searching. For your example, we have commons:Category:Ornithine, but File:Ornithine ball-and-stick.png
Deletion: Fine electronic structure
I just proposed the article fine electronic structure for deletion Wikipedia:Articles for deletion/Fine electronic structure. I tried to rescue the article before as I thought I could learn a little about spin-orbit and other corrections to the band structure of solids. The doubt about the subject is if it is related to the specific details of general matter (atoms, molecules, solids) or just solids. Maybe an expert here could give an insight. Also look at the article as it was before: [1] --MaoGo (talk) 09:05, 18 May 2018 (UTC)
Facto Post – Issue 12 – 28 May 2018
Facto Post – Issue 12 – 28 May 2018
ScienceSource fundedThe Wikimedia Foundation announced full funding of the ScienceSource grant proposal from ContentMine on May 18. See the ScienceSource Twitter announcement and 60 second video.
The proposal includes downloading 30,000 open access papers, aiming (roughly speaking) to create a baseline for medical referencing on Wikipedia. It leaves open the question of how these are to be chosen. The basic criteria of WP:MEDRS include a concentration on secondary literature. Attention has to be given to the long tail of diseases that receive less current research. The MEDRS guideline supposes that edge cases will have to be handled, and the premature exclusion of publications that would be in those marginal positions would reduce the value of the collection. Prophylaxis misses the point that gate-keeping will be done by an algorithm. Two well-known but rather different areas where such considerations apply are tropical diseases and alternative medicine. There are also a number of potential downloading troubles, and these were mentioned in Issue 11. There is likely to be a gap, even with the guideline, between conditions taken to be necessary but not sufficient, and conditions sufficient but not necessary, for candidate papers to be included. With around 10,000 recognised medical conditions in standard lists, being comprehensive is demanding. With all of these aspects of the task, ScienceSource will seek community help. Links
Editor Charles Matthews, for ContentMine. Please leave feedback for him. Back numbers are here. Reminder: WikiFactMine pages on Wikidata are at WD:WFM. ScienceSource pages will be announced there, and in this mass message. If you wish to receive no further issues of Facto Post, please remove your name from our mailing list. Alternatively, to opt out of all massmessage mailings, you may add Category:Wikipedians who opt out of message delivery to your user talk page.
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Thank you. — The Transhumanist 07:28, 30 May 2018 (UTC)
Can a PhD thesis be used as a source for a structure of an organic chemical?
Per title, that PhD thesis is a primary source but per that paragraph,
Completed dissertations or theses written as part of the requirements for a doctorate, and which are publicly available (most via interlibrary loan or from Proquest), can be used but care should be exercised, as they are often, in part, primary sources. Some of them will have gone through a process of academic peer reviewing, of varying levels of rigor, but some will not. If possible, use theses that have been cited in the literature; supervised by recognized specialists in the field; or reviewed by third parties. Dissertations in progress have not been vetted and are not regarded as published and are thus not reliable sources as a rule. Some theses are later published in the form of scholarly monographs or peer reviewed articles, and, if available, these are usually preferable to the original thesis as sources.
Shall I still use that thesis as a source? It is a good source because it shows explicitly the structure and its archaic (to this day) name on the same page. Outside of wikipedia, the PhD thesis is accessible electronically. --Ktsquare (talk) 07:03, 2 June 2018 (UTC)
- You can use it if it is correct, especially if it is the first to reveal the structure. But see if you can confirm it is correct from a secondary, or reviewing source. Even if you can't find a better source, you can put in the primary source until someone else finds a superior one. However basing a whole article off one thesis is dubious, as notability is not proved by only having one source from one author. Graeme Bartlett (talk) 08:23, 2 June 2018 (UTC)
- Some tertiary works or aggregator web sites can be used for structures eg for your use perhaps https://pubchem.ncbi.nlm.nih.gov/compound/225048 if your substance is 8-ethylcaffeine. Graeme Bartlett (talk) 08:28, 2 June 2018 (UTC)
Naphthalene-1,5-dione
Could someone have a look at Draft:Naphthalene-1,5-dione? Is that the same compound as 1,5-dioxynaphthalene? Should it have its own article, or be merged somewhere else? – Uanfala (talk) 18:26, 2 June 2018 (UTC)
- It looks to be the same substance. It's fair enough to decline AFC as there are no references. And where does all the property information come from in the chembox if it does not exist? Appears to be copied from ChemSpider predicted properties. Graeme Bartlett (talk) 23:13, 2 June 2018 (UTC)
- Yep, I came to a similar conclusion, i.e. that the chembox was completed based on projections and guesses. ChemAbs search indicates that the parent is unknown and of mild interest. --Smokefoot (talk) 02:45, 3 June 2018 (UTC)
Possible issue with <chem> markup at Propene#Combustion
Over at Propene#Combustion, there's this little equation:
I assume that the labels "propene", "oxygen", and "carbon dioxide" are meant to go under the bracket/underbrace, like they do for "water", rather than to the side of the molecules as they appear above. Anyone know how to fix this? I've been staring at the <chem> code for a while now and can't figure it out. I don't think is browser issue, as it appears the same way in various browsers and computers that I have tried. Yilloslime (talk) 19:52, 6 June 2018 (UTC)
- I can't figure out why it appears that way either. But since I think the extra text is unnecessary and the equations simply look better in the same style/font as the rest of the text, I have replaced it. -- Ed (Edgar181) 20:30, 6 June 2018 (UTC)
- @Yilloslime: The problem is coming from the last character which is a subscript in propene, oxygen and carbon dioxide, but not in the case of water. Snipre (talk) 22:29, 7 June 2018 (UTC)
Poly = 2 or >2?
I have never settled on the meaning of poly, as in polyamine. Is ethylenediamine a polyamine? My inclination is that it is not. --Smokefoot (talk) 21:06, 4 June 2018 (UTC)
- I think =2 is out, the question is >1, or >2, or >N? The gold book says about polymers the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass.[2] Multiple usually means >1. On the other hand, the convention should probably be whatever the sources say about the nomenclature. In condensed matter physics, a spin dimer is never called a polymer and dimerization is never called polymerization. --Mark viking (talk) 21:40, 4 June 2018 (UTC)
- I just recheck an encyclopedia on organic amines: it has separate sections on diamines and polyamines, which seems to jive with what you say. --Smokefoot (talk) 21:56, 4 June 2018 (UTC)
- Not referencing any source, but just thinking about my own use of poly_____, I would not call ethyldiamine a polyamine. I think poly is at least >2. Yilloslime (talk) 22:46, 4 June 2018 (UTC)
- I just recheck an encyclopedia on organic amines: it has separate sections on diamines and polyamines, which seems to jive with what you say. --Smokefoot (talk) 21:56, 4 June 2018 (UTC)
- Unadulterated logic would indicate poly to mean ≥2. Anything else would just be an arbitrary delineation in the spectrum of variability. Adendum: consider oligomers. Plasmic Physics (talk) 09:24, 5 June 2018 (UTC)
- polymer > olgiomer > dimer > monomer: A polymer is generally means much greater than two. Boghog (talk) 09:44, 5 June 2018 (UTC)
- No, 'polymer' means 'more than one', nothing more. By tradition, it is taken to mean 'much more than one'. You're missing my point. Plasmic Physics (talk) 06:08, 7 June 2018 (UTC)
- Most definitions of polymer contain the words "many" or "very high molecular weight". many > a few > one. Many is a large indefinite number that generally means much greater than two. Boghog (talk) 06:48, 7 June 2018 (UTC)
- The original Greek poly- prefix means many. Graeme Bartlett (talk) 11:28, 7 June 2018 (UTC)
- Yes, and 'many' and 'large' are subjective terms, but must by definition at least greater than one. Plasmic Physics (talk) 06:21, 8 June 2018 (UTC)
- The original Greek poly- prefix means many. Graeme Bartlett (talk) 11:28, 7 June 2018 (UTC)
- Most definitions of polymer contain the words "many" or "very high molecular weight". many > a few > one. Many is a large indefinite number that generally means much greater than two. Boghog (talk) 06:48, 7 June 2018 (UTC)
- No, 'polymer' means 'more than one', nothing more. By tradition, it is taken to mean 'much more than one'. You're missing my point. Plasmic Physics (talk) 06:08, 7 June 2018 (UTC)
- polymer > olgiomer > dimer > monomer: A polymer is generally means much greater than two. Boghog (talk) 09:44, 5 June 2018 (UTC)
- What if we shift our focus onto bulk properties? More precisely, if the substance in question has a singular structural formula, it is not a polymer; if the substance contain a gaussian mixture of formulae then it is a polymer. Compare tetracosane and polyethylene. Plasmic Physics (talk) 06:44, 8 June 2018 (UTC)
Just made a stub for this compound. If someone were willing to add the "chembox" infobox to the article I'd be very appreciative. -Darouet (talk) 20:22, 7 June 2018 (UTC)
Various Chemistry drafts
Over on WP:WPM we been working on identifying draft which come under our project and reviewing them at Wikipedia:WikiProject Mathematics/List of math draft pages. Part of this process involved finding draft which had mathematical of chemical equations in them. Quite a few of them come under your project and we have listed them at Wikipedia:List of draft pages on science and engineering. You may wish to examine these and see if any should be promoted to main space. --Salix alba (talk): 07:41, 12 June 2018 (UTC)
Deletion discussion for Naphthalene-1,5-dione
Probably of interest to participants here: Wikipedia:Articles for deletion/Naphthalene-1,5-dione. XOR'easter (talk) 23:33, 12 June 2018 (UTC)
Where to look for feasibility of a reaction
Hello there, while looking at the Cannizzaro reaction, can the aldehyde be replaced by an aldimine? Then the aldimine undergoes the reaction to yield an amine and an amide. Where can I look for information about that? At the moment, it seems original research. Secondly, on isobutyraldehyde, "it undergoes the Cannizaro reaction even though it has alpha hydrogen atom.", unsourced. On TishchenkoReaction, "the Tishchenko reaction is used to obtain isobutyl isobutyrate, a specialty solvent, sourced. So, does the isobutyraldehyde undergoes a Cannizzaro reaction to yield both the alcohol (isobutyl) and the carboxylate (isobutyrate)? Where can I look for information about that? Consequently, is or was there a collaboration on Organic Chemistry, say a Wikiproject? -- Mountainninja (talk) 01:50, 17 June 2018 (UTC)
Migration away from old texvc <math> engine
There is now a project to migrate away from the texvc renderer for <math> expressions.
This was the default a few years ago which produces PNG images, now we have a hybrid solution with uses MathJax in the backend to produce svg images and sometimes xml. There is still some legacy from texvc as it is used in the frist parsing step of the current engine. This means there are some idiosyncrasies in the syntax which differ from standard LaTex:
| Current syntax | Suggested replacement | Comment |
|---|---|---|
| $ | \$ | redefinition would involve changing the character code |
| % | \% | redefinition would involve changing the character code |
| \and | \land | causes normal align environment to fail |
| \or | \lor | see [3]; causes teubner to fail |
| \part | \partial | acceptable if the document doesn't use sectioning with \part. |
| \ang | \angle | this only conflicts with siunitx package. |
| \C | \Complex | conflicts with puenc.def e.g. from hyperref package |
| \H | \mathbb{H} | conflicts with text command \H{0} which is ő. |
| \bold | \mathbf | |
| \Bbb | \mathbb | |
| \pagecolor | remove | not needed and not working anymore, done on en-wiki mainspace |
<ce>...</ce> |
<chem>...</chem> |
Chemistry environment, done on en-wiki mainspace |
The first step in the project will involve deprecating the old syntax and running a bot or semi-automated edits to change the syntax. These should not result in any visible change to the pages. The bot doing the work is User:Texvc2LaTeXBot which is currently seeking approval. Changes will also be made to the Visual Editor to produce the new syntax.
Subsequent stages in the project are discussed at mw:Extension:Math/Roadmap, these involve some more complex problems with the <chem> syntax. Eventually the texvc part will be removed completely and there may be some slight change to the rendered output. The main discussion of the project happens at T195861 and your input is welcome.
Discussion on the English wikipedia should be on WT:WPM--Salix alba (talk): 15:58, 22 June 2018 (UTC)
Opinions sought
as to Draft:Amphetamine synthesis.Feel free to accept at your discretion, shall this be encyclopedic-ally notable enough :)∯WBGconverse 04:56, 27 June 2018 (UTC)
Facto Post – Issue 13 – 29 May 2018
Facto Post – Issue 13 – 29 May 2018
 The Editor is Charles Matthews, for ContentMine. Please leave feedback for him, on his User talk page.
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Facto Post enters its second year, with a Cambridge Blue (OK, Aquamarine) background, a new logo, but no Cambridge blues. On-topic for the ScienceSource project is a project page here. It contains some case studies on how the WP:MEDRS guideline, for the referencing of articles at all related to human health, is applied in typical discussions. Close to home also, a template, called {{medrs}} for short, is used to express dissatisfaction with particular references. Technology can help with patrolling, and this Petscan query finds over 450 articles where there is at least one use of the template. Of course the template is merely suggesting there is a possible issue with the reliability of a reference. Deciding the truth of the allegation is another matter. This maintenance issue is one example of where ScienceSource aims to help. Where the reference is to a scientific paper, its type of algorithm could give a pass/fail opinion on such references. It could assist patrollers of medical articles, therefore, with the templated references and more generally. There may be more to proper referencing than that, indeed: context, quite what the statement supported by the reference expresses, prominence and weight. For that kind of consideration, case studies can help. But an algorithm might help to clear the backlog. 
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Any love for Chromatography?
The Fundamental resolution equation article is in need of love and is on the same equation as the Purnell equation article. I hate tedious algebra (talk) 04:03, 16 July 2018 (UTC)
Acid strength definition
Empirically, an acid can be said to be completely dissociated in solution when the concentration of molecules, HA, is below the detection limit for the species. There appear to be two, mutually incompatible, ways of quantifying what a strong acid is. See acid strength and acid dissociation constant for details.
- An acid with a pK value less than -1.76.This applies only to aqueous solutions
- An acid which is effectively 100% dissociated in solution
The first is the number -log10 55.5. 55.5 is the concentration/1M of H2O pure water. This seems to be the criterion commonly used for designating a compound as a superacid.
The second depends on the buffer capacity of the solvent, which rises very steeply with decreasing pH, starting at about pH 1 in aqueous solutions. This is independent of the pK value of the acid and is the cause of the solvent levelling effect.
What, if anything, should be done in WP about this contradictory state of affairs? Petergans (talk) 09:35, 19 July 2018 (UTC)
- For the purposes of this does strong acid = superacid? Superacid is defined by IUPAC "A medium having a high acidity, generally greater than that of 100 wt.% sulfuric acid" which our current sulfuric acid chembox would indicate as being anything below a pka of -3 (?). If strong acid is something else, my first question is: is there a formal definition? I've always thought it a loose term (in my head anything with a pka <1 is strong). If no universal definition exists it's not our job to create one.--Project Osprey (talk) 08:39, 20 July 2018 (UTC)
- @Project Osprey: Hi you are right in that a superacid has an acidity greater than 100% sulphuric acid or less than -12 on the Hammett acidity function. At this level of acidicity pH isn't really used anymore. EvilxFish (talk) 13:46, 20 July 2018 (UTC)
What is a metal in chemistry?
Is there a chemistry-based definition of a metal? I suspect not. If there was one I presume there would be no argh-bargy about where to draw the line of demarcation between metals and non metals, at least within the discipline of chemistry. Sandbh (talk) 07:57, 8 May 2018 (UTC)
- There are several definitions, ranging from the simple (anything shiny and conductive) to the complex (unfilled electronic band at the fermi level). The problem, as your question points out, it in applying a binary ‘is/isn’t’ definition to what is in reality a gradient. Where you put the line is somewhat arbitrary (where does blue end and green begin?). In terms of Wikipedia, how/where is this a problem?--Project Osprey (talk) 08:54, 8 May 2018 (UTC)
Thank you.
I was interested in definitions based on chemical properties instead of physical properties such as shininess or conductivity. For example, simple cation formation or having at least one basic oxide. The challenge is that there are some metals like tantalum or tungsten that meet neither of these criteria. Just what is it, from a chemist's point of view, that warrants classifying Ta and W as metals?
There is not much of a gradient, as I understand it, in distinguishing between metals and nonmetals. The consensus of the literature classifies B, Si, Ge, As, Sb, and Te as metalloids. And Wikipedia classifies At as a metalloid, on the basis of its apparent properties, noting it has been predicted to have a fully metallic band structure. So, apart from H, elements to the left of the metalloids in the periodic table are metals.
The context for my question is a desire to improve our metal article. It seems odd that there does not seem to be an inclusive definition of a metal based purely on chemical properties. Sandbh (talk) 10:38, 9 May 2018 (UTC)
Metallic bonding
- heading added Sandbh Sandbh (talk) 01:38, 12 May 2018 (UTC)
- In that case I'd define a metal (somewhat cyclically) as anything which engages in metallic bonding. That is the chemical phenomenon behind most of their physical properties. Sadly the metallic bonding page needs quite a bit of work. --Project Osprey (talk) 10:58, 9 May 2018 (UTC)
That would be awkward since H is capable of forming alloy-like hydrides, featuring metallic bonding, with some transition metals. I'm not pretending this is an easy question—I don't yet see how to do it without including at least one physical property like conductivity. Sandbh (talk) 13:03, 9 May 2018 (UTC)
- I don't think that's a strong argument. I imagine most elements can be alloyed but that doesn't mean that they're metallic in their own rights. Hydrogen is not a metal under standard conditions, that's obvious just by looking at it. That you can force it into displaying metallic properties is besides the point. --Project Osprey (talk) 13:31, 9 May 2018 (UTC)
- Well, it seems like we'd have to add another criterion to the definition so as to exclude H, given it is capable of metallic bonding. You seem to be inferring that this would be a physical property like appearance. The only extra chemical property I can think of is to specify an ionisation energy less than or equal to that of mercury, but this also seems slightly circular. Sandbh (talk) 05:42, 10 May 2018 (UTC)
- @Project Osprey: @Sandbh: I think the intent was to look at the pure element – which almost recreates our dividing line perfectly (if you add astatine as a metal), but excludes bismuth as α-Bi is isostructural to α-As and α-Sb. Double sharp (talk) 14:56, 9 May 2018 (UTC)
- I have some reservations about relying on the wooly concept of a "metallic bond". That aside, the literature consensus is to treat Bi as a metal largely on the basis of its basic trioxide, the structure of which is also more like that of a typical metallic oxide unlike the molecular oxides of Sb and As. So, the definition would become something like, "In the periodic table, any element which (a) features a structure characterised by "metallic" bonding; or (b) has a basic oxide, is classified as a metal." Sandbh (talk) 12:08, 10 May 2018 (UTC)
- I presume there is some notion of a standard temperature and pressure for this, because otherwise just about everything should be metallisable. But then at 0 °C and 1 bar (IUPAC standard temperature and pressure), α-Sn is the stable allotrope (which is certainly not characterised by metallic bonding), and both SnO and SnO2 are amphoteric. Double sharp (talk) 15:08, 10 May 2018 (UTC)
- @Double sharp: Thank you. Yes, the definition I had in mind applies at IUPAC's SATP i.e. standard ambient temperature and pressure or 25 °C and 1 bar of pressure. I don't know, but I suspect SATP is more useful in considering the properties of the elements than STP given the complication caused by the reversion of white tin to grey tin at STP.
- I presume there is some notion of a standard temperature and pressure for this, because otherwise just about everything should be metallisable. But then at 0 °C and 1 bar (IUPAC standard temperature and pressure), α-Sn is the stable allotrope (which is certainly not characterised by metallic bonding), and both SnO and SnO2 are amphoteric. Double sharp (talk) 15:08, 10 May 2018 (UTC)
- I have some reservations about relying on the wooly concept of a "metallic bond". That aside, the literature consensus is to treat Bi as a metal largely on the basis of its basic trioxide, the structure of which is also more like that of a typical metallic oxide unlike the molecular oxides of Sb and As. So, the definition would become something like, "In the periodic table, any element which (a) features a structure characterised by "metallic" bonding; or (b) has a basic oxide, is classified as a metal." Sandbh (talk) 12:08, 10 May 2018 (UTC)
- @Project Osprey: @Sandbh: I think the intent was to look at the pure element – which almost recreates our dividing line perfectly (if you add astatine as a metal), but excludes bismuth as α-Bi is isostructural to α-As and α-Sb. Double sharp (talk) 14:56, 9 May 2018 (UTC)
- More importantly perhaps is the question of what we mean by a structure characterised by metallic bonding. Grey tin has the diamond structure but is also a semimetal in the physics based sense, even though it behaves like a semiconductor. As a semimetal there is presumably some vestige of metallic bonding. Then again, we can always say metallic bonding means "full value" metallic bonding therefore semimetals (physics) are not counted. In which case the suggested definition based on chemical properties would work. Sandbh (talk) 08:32, 11 May 2018 (UTC)
- I'm confused now. Are we talking about 'metal' as in a state of matter (metallic state), or is this about metallic elements?--Project Osprey (talk) 09:05, 11 May 2018 (UTC)
- @Project Osprey: Metallic elements. Sandbh (talk) 02:21, 12 May 2018 (UTC)
- If we count semimetals, then carbon is a metal; if we exclude semimetals and demand basic oxides, then grey tin is not a metal while white tin is. I find the former distasteful for obvious reasons and the latter distasteful since there is no chemical change involved. Using cation formation leads to a more pleasant outcome; although I'm persuaded that this puts antimony on the metallic side, I don't find this problematic as it is electropositive enough to form compounds which can be considered salts. (I will have to look up germanium chemistry, though.) Double sharp (talk) 09:30, 11 May 2018 (UTC)
- I'm confused now. Are we talking about 'metal' as in a state of matter (metallic state), or is this about metallic elements?--Project Osprey (talk) 09:05, 11 May 2018 (UTC)
- More importantly perhaps is the question of what we mean by a structure characterised by metallic bonding. Grey tin has the diamond structure but is also a semimetal in the physics based sense, even though it behaves like a semiconductor. As a semimetal there is presumably some vestige of metallic bonding. Then again, we can always say metallic bonding means "full value" metallic bonding therefore semimetals (physics) are not counted. In which case the suggested definition based on chemical properties would work. Sandbh (talk) 08:32, 11 May 2018 (UTC)
Sb3+ and Ge2+ cations
- heading added Sandbh (talk) 08:46, 13 May 2018 (UTC)
The proposed definition of a metal applies at SATP. It does not matter if, at temperatures lower or higher than 25 °C, the metal in question becomes a semimetal, semiconductor, or an insulator. AFAIK there is no simple Sb3+ cation. The closest I have seen in the literature is [Sb(H2O)4(OH)2]+. The compound Sb8(GaCl4)2, which contains the homopolycation, Sb82+, was also prepared in 2004. The status of Sb "salts" was strongly criticised by Axiosaurus on the metalloid talk page. Evidence for the existence of a simple Sb cation, or a genuine Sb salt, appears to be lacking. Sandbh (talk) 12:40, 12 May 2018 (UTC)
- @Sandbh: @Droog Andrey: (since I think these papers would interest both of you; incidentally, @Droog Andrey:, do you know where I could find those papers suggesting the existence of Sb3+ in perchloric acid media, since that's the way the standard reduction potential for Bi3+/Bi was measured?):
- Here are some quotes on Sb3+:
- "Other studies into the speciation of antimony(III) include one on the solubility of stibnite [Sb2N3] in HCl–NaCl solutions conducted by Ovchinnikov et al. (1983). Their data suggests that chloride complexing of trivalent antimony is unimportant in the temperature range 180 to 300°C (although these authors concluded differently). In sulfur free systems, antimony compounds hydrolize to form antimonous acid SbOH0
3, which predominates over a wide range of pH. In the acid range, Sb(OH)+
2 is formed, and only at very high acidities is the free Sb3+ ion stable." (Ralf E. Krupp, 1988: "Solubility of stibnite in hydrogen sulfide solutions, speciation, and equilibrium constants, from 25 to 350°C"; 10.1016/0016-7037(88)90164-0) - "The accurate value of the standard potential of antimony against Sb3+ ions is not known since single Sb(III) ions exist in very small concentration in aqueous solution. Solubility determinations of Sb4O6 in HClO4 indicate [4, 5] that dissolved trivalent antimony is mainly in the form SbO+ (in the pH range 0 to 1)." (Past Vello's section on Sb in Standard Potentials in Aqueous Solution, 1985; this suggests to me that you need to go to negative pH to have a chance of seeing Sb3+).
- Ab initio simulations support the existence of a Sb3+ aqua ion, although the above observations make it quite clear that you will not see any experimental evidence for it until the pH goes really low. See for example 10.1016/j.cplett.2011.05.060, which discusses Sb3+ along with the stable trivalent cations (Al3+, Fe3+, V3+, Ir3+, La3+, and Ce3+); I presume they are considering hydrolysis only from the metal cation itself, rather than from the acidity of the medium. The ion appears to have an interesting structure: "A completely different system is the main group ion Sb(III) with its lone electron pair destabilising the hydrate [38]. As this electron pair occupies a considerable space, it induces the formation of two different hydration hemispheres, one with four tightly bound ligands at a distance of 2.2 Å and another one on the opposite side with four much more loosely bound water molecules located 2.7 Å far from the ion. The latter are responsible for frequent exchanges between first and second hydration sphere, leading to an MRT value of 6 ps for first shell ligands and a very low MRT (< 2 ps) for those of the second shell, which is equally unsymmetric as the first shell, with 5 plus 8 ligands."; see 10.1021/ic901737y for more about this structure, which is due to the large space occupied by the 5s electron pair on Sb3+; Sn2+ has a similar issue. This is in stark contrast to As3+ which hydrolyses pretty much instantly; the article says "In the case of this smaller group V cation, the effect of the lone pair is apparently strong enough to cause an immediate hydrolysis, while in the heavier analogue Sb(III) it only leads to a strongly distorted hydration structure (vide supra)." Similar ions are Ge4+, Sn4+, and Pb4+ which hydrolyse on the picosecond scale. The final stable forms appear to be As(OH)2+ (there seems to be a typo in the article), Ge(OH)3(H2O)+, and hexacoordinate and heptacoordinate species of the form M(OH)+
aq for Sn and Pb respectively. (OTOH, Zr4+, Hf4+, Ce4+, and U4+ are confirmed to be real stable tetrapositive cations). - I will also add a word about Ge2+. It seems to be capable of existence (10.1002/jcc.21315) based on computational studies, and have a similarly distorted structure, again like Sn2+ and Sb3+ due to the lone pair. Given this, I think I might even dare to call germanium a metal as well as antimony. At least for the s- and p-block metals, it seems to be a sound criterion to demand aqueous cation formation; the d-block metals seem to require a somewhat different treatment. Double sharp (talk) 16:41, 12 May 2018 (UTC)
@Double sharp: @Droog Andrey: thank you Double sharp for those sources.
I now think too much significance is being attached to aqueous cation formation for As?, Sb, and Bi (and Ge). The species concerned seem to found only in highly acidic media, perhaps requiring negative pH in the case of Sb. I tend to be reminded of the claim that Hg was a transition metal based on the purported existence of Hg(IV) even though, as Jensen noted, the experimental conditions were quite extreme. In a similar vein, I'd regard the presence of Ge?, As?, Sb, and Bi aqueous cations as being too marginal to warrant classifying any of these elements as metals.
The original proposed definition stands up reasonably well i.e. "In the periodic table, any element which (a) features a structure characterised by "metallic" bonding; or (b) has a basic oxide, is classified as a metal." While Bi comprises covalently bonded atoms stacked in layers, its basic oxide is the starting point for most Bi chemisty. Sandbh (talk) 10:41, 13 May 2018 (UTC)
- @Sandbh: Is Bi2O3 really completely basic, though? It's definitely more basic than Sb2O3, but Bi2O3 will dissolve in warm and very concentrated KOH.
- Anyway, I don't agree that these species are irrelevant just because the unhydrolysed forms only occur at very low pH (except for As3+, which I agree does not exist as an aqua complex). Such a criterion would also exclude Pb2+, which doesn't even appear in the E–pH diagram for Pb species in The Aqueous Chemistry of the Elements even though it goes down to pH −1; Sn2+ is in a similar position, though it is called that in that book for simplicity. Yet I think we all would agree that tin and lead are metals. There does seem, however, to be a difference between elements that form and elements that don't form aqueous cations that is observable in chemistry: looking at Greenwood and Earnshaw, as well as 10.1002/jccs.196400020 for Ge(ClO4)2, it appears that GeII, GeIV, SbIII, BiIII, and PoIV form acidic oxoacid salts (with scare quotes possibly added), while AsIII, SeIV, and TeIV only form basic ones. Since Te also forms the Te(OH)3+ cation, simply relaxing the criterion to allow all incomplete hydroxy complexes doesn't seem to give the desired result (noting the dangers of this), since Te seems quite clearly to be closer to nonmetals than metals (it acts much like Se); requiring aqua cations to form seems better. We all have no hesitation talking about Tl3+, Sn2+, Pb2+, and Bi3+ even if those specific species rarely appear, because they are starting points of hydrolysis and they actually exist; why then should we not allow in Ge2+ and Sb3+? Double sharp (talk) 12:56, 13 May 2018 (UTC)
- It should probably be noted that various nonmetals like iodine and sulfur can form what might be considered simple cations in some nonaqueous media. OrganoMetallurgy (talk) 13:12, 13 May 2018 (UTC)
- P. B. Saxena has made some interesting comments about I+ and I3+ cations in pp. 112–118 of his Chemistry of Interhalogen Compounds (link). One argument he puts in support of his case is that many iodine compounds liberate iodine at the cathode when electrolysed in their molten or aqueous states, such as ICl, IBr, ICN, INO3, I2SO4, and so on. I must confess I'm not terribly convinced by some of this, though; for example, indeed ICl acts as a strong electrophilic iodinating reagent, but is a bare I+ cation really formed? BTW radon also forms simple Rn2+ cations in nonaqueous media; Greenwood and Earnshaw indeed mention cations of S, Se, Te, Cl, Br, and I formed in sufficiently oxidising solvents (e.g. oleum), but these are all polyatomic cations AFAIK, not like the simple cations of metals we were previously discussing. Double sharp (talk) 14:14, 13 May 2018 (UTC)
- @Double sharp: That's not what I was referring to. Rather I'm talking about stuff like Bis(pyridine)iodonium(I) tetrafluoroborate which is essentially pyridine solvate a salt of the I+ cation and the sulfur compounds discussed this doi:10.1021/ic1012582 article. They may require ligands for stability, but so what? I think those sorts of compounds (and there are many other kinds I could mention if anyone's interested) have been rather artificially considered a separate class of compounds from metal complexes. OrganoMetallurgy (talk) 17:59, 13 May 2018 (UTC)
- @OrganoMetallurgy: Oh, I see. Yes, I agree that the distinction is rather artificial. Please do mention some more; I'd be interested in seeing how many of the nonmetals can be roped into doing something like this! ^_^ Double sharp (talk) 23:43, 13 May 2018 (UTC)
- @Double sharp: It seems that phosphorus, arsenic, antimony, and bismuth can all form bipyridine complexes doi:10.1039/C5SC02423D and sulfur, selenium, and tellurium form complexes with diiminopyridine doi:10.1021/ja9073968 and bromine and iodine both form bis pyridine complexes. --OrganoMetallurgy (talk) 22:34, 17 May 2018 (UTC)
- @OrganoMetallurgy: Great, thank you so much for these examples! So in groups 15 through 17 only the strongest nonmetals N, O, F, and Cl remain unconquered in our lists so far. Double sharp (talk) 23:43, 17 May 2018 (UTC)
- @Double sharp: It seems that phosphorus, arsenic, antimony, and bismuth can all form bipyridine complexes doi:10.1039/C5SC02423D and sulfur, selenium, and tellurium form complexes with diiminopyridine doi:10.1021/ja9073968 and bromine and iodine both form bis pyridine complexes. --OrganoMetallurgy (talk) 22:34, 17 May 2018 (UTC)
- @OrganoMetallurgy: Oh, I see. Yes, I agree that the distinction is rather artificial. Please do mention some more; I'd be interested in seeing how many of the nonmetals can be roped into doing something like this! ^_^ Double sharp (talk) 23:43, 13 May 2018 (UTC)
- @Double sharp: That's not what I was referring to. Rather I'm talking about stuff like Bis(pyridine)iodonium(I) tetrafluoroborate which is essentially pyridine solvate a salt of the I+ cation and the sulfur compounds discussed this doi:10.1021/ic1012582 article. They may require ligands for stability, but so what? I think those sorts of compounds (and there are many other kinds I could mention if anyone's interested) have been rather artificially considered a separate class of compounds from metal complexes. OrganoMetallurgy (talk) 17:59, 13 May 2018 (UTC)
- P. B. Saxena has made some interesting comments about I+ and I3+ cations in pp. 112–118 of his Chemistry of Interhalogen Compounds (link). One argument he puts in support of his case is that many iodine compounds liberate iodine at the cathode when electrolysed in their molten or aqueous states, such as ICl, IBr, ICN, INO3, I2SO4, and so on. I must confess I'm not terribly convinced by some of this, though; for example, indeed ICl acts as a strong electrophilic iodinating reagent, but is a bare I+ cation really formed? BTW radon also forms simple Rn2+ cations in nonaqueous media; Greenwood and Earnshaw indeed mention cations of S, Se, Te, Cl, Br, and I formed in sufficiently oxidising solvents (e.g. oleum), but these are all polyatomic cations AFAIK, not like the simple cations of metals we were previously discussing. Double sharp (talk) 14:14, 13 May 2018 (UTC)
Anyway, I think the case of Sb(H2O)83+ is rather different from that of HgIV. The latter, if it exists at all, only appears in one compound at extreme conditions and does not illuminate anything else about Hg chemistry, which is resolutely that of a post-transition metal; so it is not terribly important for classification, unlike what is expected for Cn. But Sb3+ can be considered the starting point of hydrolysis that leads to Sb(H2O)4(OH)2+ and thence to Sb(OH)3; given that Sb has the ability to form "salts" formally involving a simple Sb3+ cation, like Bi, Po, and At but unlike As, Se, and Te (which only form basic salts), thinking of this cation as a starting point does seem to help understanding Sb chemistry even if it itself only appears at extreme conditions. I would say much the same of the cations Tl3+, Sn2+, Pb2+, Ce4+, Zr4+, and Hf4+. On the other hand, since As2O3 is a predominantly acidic oxide, and AsIII appears to quickly hydrolyse all the way to As(OH)3 (arsenious acid) in water, I would agree that thinking of As3+ is unhelpful.
When it comes down to it, all metals have a nonmetallic side (even caesium forms alkalides) and all nonmetals have a metallic side (even helium has a few similarities to beryllium), and especially around the metalloid line a binary distinction is difficult to maintain. We are not saying that antimony is wholly metallic or wholly nonmetallic; both statements are nonsense. To the extent that the question "is Sb a metal or not" makes sense, it must be asked in terms of which one gives a better first-order understanding of what one might expect of its physical and chemical properties. Since +3 is antimony's predominant oxidation state, in which Sb forms a cation and has an amphoteric oxide, I think it is less misleading to call it a metal with caveats than a nonmetal with caveats. The approach of looking at the most stable oxidation state in the p-block incidentally calls B, Si, Ge, As, and Te nonmetals, Sb a metal, and is agnostic on At given that At3+ has not yet been found AFAIK (although At+ and AtO+ being known suggests to me that it is a possibility). (Ge ends up on the nonmetal side because it forms a cation and has an amphoteric oxide in its unstable +2 oxidation state, and does neither in its stable +4 state.) Double sharp (talk) 06:04, 14 May 2018 (UTC)
- Hmm, 10.1021/jp3099413 shows that even AtO+ is hydrolysed to AtOOH already around pH 2, so if At3+ does exist it must be at really low pH again. So I think I'd rather amend it to include all oxidation states found in species that actually appear on the element's E–pH diagram, so that astatine qualifies as a metal by virtue of the At+ cation. OTOH, Ge2+ would still not qualify germanium as one. Double sharp (talk) 08:28, 14 May 2018 (UTC)
@Double sharp: Earlier you wrote, "Is Bi2O3 really completely basic, though? It's definitely more basic than Sb2O3, but Bi2O3 will dissolve in warm and very concentrated KOH." In his Treatise on Inorganic Chemistry (1956 p. 677), Remy wrote, "The insolubility of bismuth oxide in dilute alkalis, as compared with the amphoteric oxides of arsenic and antimony, marks it out as being definitely a basic oxide." That seems to be the explanation then for regarding bismuth oxide as being basic. So, at this stage, the original proposed definition based on having "metallic" bonding or having a basic oxide appears to still hold. Sandbh (talk) 06:01, 15 May 2018 (UTC)
Apparent absence of chemical properties
- heading added Sandbh Sandbh (talk) 01:50, 12 May 2018 (UTC)
I would say that there isn't really any chemical properties that define metals. They do tend to have lower electronegativity than nonmetals, but there are exceptions. As far as I'm aware, in the context of chemistry, a metal is a element that in its pure form, under standard conditions, is considered metal ( elements that are considered metalloids are sometimes also included), based on its physical characteristics. Or alternatively to the electrical properties of a substance. OrganoMetallurgy (talk) 18:53, 11 May 2018 (UTC)
- I was going to say I agreed with you as there were no chemical properties that appeared to be common to all metals. The fall back then becomes physical properties. However, I now tend to think that any element which…
- can form a simple cation in aqueous solution; or
- has a basic oxide; or
- adopts multiple oxidation states differing by one, and forms coloured compounds…
- merits being classified as a metal.
- I could be wrong but I believe this chemistry-based definition covers all the elements commonly counted as metals. No need to invoke any physical properties (I suspect the coloured compound criterion could be dropped). Sandbh (talk) 12:32, 15 May 2018 (UTC)
- And what if we think here in terms of 'if we take a piece of metal and we react it vs. if we take a piece of non-metal and we react it, do we know reactions that distinguish the metal from the non-metal (as in a non-true example: 'metals dissolve in acids under evolution of hydrogen, non-metals do not dissolve in acids under evolution of hydrogen' - noting that some metals do not dissolve in acids (in that way))? --Dirk Beetstra T C 13:04, 15 May 2018 (UTC)
- Agreeing with Dirk, I wonder about where the above discussion is nudging toward. In my institution's inorganic courses, we don't dwell on defining a metal ion, transition metal (the Zn issue), a lanthanide (the lanthanum issue), a main group element (Zn again), a metalloid (gray vs red Se), an organometallic cmpd (is Mo(CO)6 organometallic?), etc. For bulk metals, we note that the electrical conductivity of metals follows a 1/T relationship whereas semiconductors go the other way. On the other hand for an encyclopedia, we gotta say something. I just recommend flexibility.--Smokefoot (talk) 13:46, 15 May 2018 (UTC)
- I think that in practice, the real definition of a metal just depends on whatever is most convenient at the moment. For those elements on the borderlines, it may sometimes be useful to include them as metals, and sometimes useful to exclude them. It's just that when considering metals is not the main point, and we're still colouring elements by metallicity on a nice periodic table graphic in one corner or at the bottom, we need to pick some defaults, and they might as well be the least misleading defaults to the novice who takes those colours at face value. That does not in any way stop us from changing things around if the context makes it reasonable to do so, as you say. Double sharp (talk) 15:31, 15 May 2018 (UTC)
- @Sandbh: Doesn't this definition classify chlorine as a metal if taken literally? Chlorine forms ClF3, ClO2, and ClF5, which have Cl in the +3, +4, and +5 states respectively (differing by one). ClO2 is a yellowish-green gas and hence meets the colour requirement. Double sharp (talk) 04:57, 16 May 2018 (UTC)
- @Double sharp: Yes, it does—Headslap!—and I'm currently considering what to do about this. Any suggestions? Sandbh (talk) 11:13, 16 May 2018 (UTC)
- @Sandbh: Doesn't this definition classify chlorine as a metal if taken literally? Chlorine forms ClF3, ClO2, and ClF5, which have Cl in the +3, +4, and +5 states respectively (differing by one). ClO2 is a yellowish-green gas and hence meets the colour requirement. Double sharp (talk) 04:57, 16 May 2018 (UTC)
- I think that in practice, the real definition of a metal just depends on whatever is most convenient at the moment. For those elements on the borderlines, it may sometimes be useful to include them as metals, and sometimes useful to exclude them. It's just that when considering metals is not the main point, and we're still colouring elements by metallicity on a nice periodic table graphic in one corner or at the bottom, we need to pick some defaults, and they might as well be the least misleading defaults to the novice who takes those colours at face value. That does not in any way stop us from changing things around if the context makes it reasonable to do so, as you say. Double sharp (talk) 15:31, 15 May 2018 (UTC)
- Agreeing with Dirk, I wonder about where the above discussion is nudging toward. In my institution's inorganic courses, we don't dwell on defining a metal ion, transition metal (the Zn issue), a lanthanide (the lanthanum issue), a main group element (Zn again), a metalloid (gray vs red Se), an organometallic cmpd (is Mo(CO)6 organometallic?), etc. For bulk metals, we note that the electrical conductivity of metals follows a 1/T relationship whereas semiconductors go the other way. On the other hand for an encyclopedia, we gotta say something. I just recommend flexibility.--Smokefoot (talk) 13:46, 15 May 2018 (UTC)
- And what if we think here in terms of 'if we take a piece of metal and we react it vs. if we take a piece of non-metal and we react it, do we know reactions that distinguish the metal from the non-metal (as in a non-true example: 'metals dissolve in acids under evolution of hydrogen, non-metals do not dissolve in acids under evolution of hydrogen' - noting that some metals do not dissolve in acids (in that way))? --Dirk Beetstra T C 13:04, 15 May 2018 (UTC)
- 10.1021/ed056p712 agrees with this pessimistic view, BTW. It suggests that metals can be distinguished by hardly ever assuming negative oxidation states, but we all know that gold means that this is not a criterion but a guideline. It also mentions that the metals become more nonmetallic in their properties as their oxidation state is increased (which is one reason for the very nonmetallic chemical behaviour of some of the 4d and 5d metals, for which the lower and more metallic oxidation states are unstable). It suggests high electrical conductivity in all three dimensions as a distinguishing physical property, but that approach would have us considering arsenic as a metal. Double sharp (talk) 15:28, 17 May 2018 (UTC)
Here's an update of the suggested definition of a metal, based on chemical properties:
Any element which… * forms a simple cation in aqueous solution; or * has a basic oxide; or * uses d or f electrons in chemical bonding… merits being classified as a metal.
Sandbh (talk) 10:25, 18 May 2018 (UTC)
- @Sandbh: While I cannot think of anything that fails this definition at present that I think you can reasonably consider a metal, I dislike how it essentially rules the d- and f-block elements as metals by fiat (I guess adding the g-block elements once they are discovered). There must be something else that can be pointed to to support their metallicity. There are s-block metals and nonmetals, and p-block metals and nonmetals, so I have a hard time believing that block membership proves metallicity by itself. If it so happens that all d-block and f-block elements are metals (which I agree with), great, but I don't think we can declare it as a postulate. As Bertrand Russell wrote, "The method of 'postulating' what we want has many advantages; they are the same as the advantages of theft over honest toil." Double sharp (talk) 15:26, 22 May 2018 (UTC)
@Double sharp: The challenge is how to cater for metals that don't form simple cations namely Zr, Hf; Nb, Ta; W; Tc; and Os. The first four of these form interstitial (metallic) hydrides. The only suitable chemical property I can see for W, Tc and Os is their capacity to exist in more than eight integral oxidation states. So that would give:
Any element which… * forms a simple cation in aqueous solution; or * has a basic oxide; or * forms an interstitial hydride; or * can exist in more than eight integral oxidation states… merits being classified as a metal.
The capacity to form an interstitial hydride, as I understand it, is partly related to the existence of a metallic lattice, so I'm OK with that criterion.
The capacity to exist in more than eight integral oxidation states is less satisfactory because it isn't immediately clear why it's associated with metallicity. Still, it's an improvement on the former definition. Thoughts? Sandbh (talk) 01:27, 1 July 2018 (UTC)
- @Double sharp: After further thinking it's probably more helpful to flag the anomalies and note why the elements concerned are still regarded as metals. Like so:
- Metal. An element which forms a simple cation in aqueous solution, or which has a basic oxide, or an interstitial hydride. Tungsten, technetium, and osmium exhibit none of these properties but are nevertheless classified as metals in light of their shared similarities with some other metals. These similarities include the capacity to exist in multiple oxidation states usually differing by 1, the formation of coloured solutions in water, and the formation of magnetic compounds. Sandbh (talk) 03:20, 21 July 2018 (UTC)
Metal article lede construction
- heading added Sandbh (talk) 01:25, 12 May 2018 (UTC)
One approach (which I think should be almost mandatory for most articles), is to build the lede on major (WP:TERTIARY) sources (not the damn OED). What are the "bibles" on metals? Get them and rely on them. As it stands, readers are force-fed these lame sources at the first five references:
- 1) μέταλλον Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library
- 2) Oxford Dictionaries
- 3) Encyclopædia Britannica
- 4) John C. Martin. "What we learn from a star's metal content". New Analysis RR Lyrae Kinematics in the Solar Neighborhood. Retrieved September 7, 2005.
- 5) BEC. "Physicists Achieve Early Stages of a New, Solid State of Hydrogen". sciencealert.com. sciencealert.com. Retrieved 7 January 2017.
--Smokefoot (talk) 13:50, 9 May 2018 (UTC)
- The metal article is a challenge. AFAIK there is no global bible that deals with all aspects of metals. The subject seems to be so big that what bibles there are only (largely) deal with either the chemistry, structures, metallurgy, physics, or engineering aspects of metals. So, to some degree, one is forced to fall back on the most general of sources like the OED or Britannica in order to give the broadest possible description of a metal. Then drill down into the more specialised sources, like the lede currently does with astronomy. That aside, I do agree that even just the lede could be improved. Sandbh (talk) 01:25, 12 May 2018 (UTC)
Facto Post – Issue 14 – 21 July 2018
| Facto Post – Issue 14 – 21 July 2018
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Removal of Chemistry Portal from the template, put it back
Just because the portal has been abandoned does not mean that the portal is useless. There is valuable information on the portal, especially if a person is interested in the quickly seeing the vocabulary for a field and not just reading an encyclopedia article. Unless the plan is to remove the PORTAL parameter from all of the WikiProject templates, it should be put back. Leave it to the reader to judge the usefulness of the information on the portal page. Use case example: a person is learning a foreign language and needs to learn the most important words in Chemistry. The Chemistry portal page will give them that information where the Chemistry article will not.
Portals are setup to do rotations of articles automatically. As long as the choice of articles is contained in the Top or High category, if code is written to randomly choose an article from one of those two categories by just grabbing the introduction automatically (TextExtracts), it does not need to be maintained in order for it to work. Zzmonty (talk) 07:55, 25 July 2018 (UTC)
Nanodumbbell
I just started Nanodumbbell and have no idea what I'm doing. Please visit the article and see if the "Effect of Surfactant on Growth of ZnO Nanodumbbells..." external link is the right thing. Are these things silica or zinc or what? Many thanks! :) Anna Frodesiak (talk) 23:22, 24 July 2018 (UTC)
- Usually one starts an article because we know our subject and we can demonstrate that the topic is notable. Notable usually means that the topic is featured in a book or a review article. But some good articles get started for strange reasons, and perhaps yours is an example of such. Probably however, if you have no idea what you are doing, the article is not worth writing.--Smokefoot (talk) 00:58, 25 July 2018 (UTC)
- I agree it's kind of weird to start an article on a topic you don't know about :-) On the other hand, I've done a little searching and have convinced myself this is a reasonable topic for an article. Mostly I found research papers, but also some more general references, such as "Handbook of Less-Common Nanostructures". Google Books. Retrieved 2018-07-25. so I'm inclined to keep this and nurture it. -- RoySmith (talk) 13:49, 25 July 2018 (UTC)
- It's the opposite axis as a molecular gyroscope. Rigid rotor is probably the parent article but that is already long and high-level/mathy, so this would not fit there (but should link back and forth) IMO. DMacks (talk) 14:30, 25 July 2018 (UTC)