Wikipedia talk:WikiProject Chemistry/Archive 41

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ΔΔG* vs selectivity

Help wanted: Where in Wikipedia is the relationship ΔΔG* vs selectivity described or graphed for various temperatures?--Smokefoot (talk) 02:49, 23 February 2017 (UTC)

I see the idea sort-of mentioned at Curtin–Hammett_principle and Energy profile (chemistry) but I don't see specifically as a function of temperature at a glance. DMacks (talk) 03:10, 23 February 2017 (UTC)
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.
ΔΔG* (kcal) k1/k2 (273 K) k1/k2 (298 K) k1/k2 (323 K)
1.0 6.37 5.46 4.78
2.0 40.60 29.80 22.90
3.0 259.00 162.00 109.00
4.0 1650.00 886.00 524.00
5.0 10500.00 4830.00 2510.00

--Smokefoot (talk) 16:26, 23 February 2017 (UTC)

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)
Here's a non-zeropadded way of decimal alignment. It's a "differently ugly" hack:
ΔΔG* (kcal) k1/k2 (273 K) k1/k2 (298 K) k1/k2 (323 K)
1.0 6 .37 5 .46 4 .78
2.0 40 .6 29 .8 22 .9
3.0 259 162 109
4.0 1650 886 524
5.0 10500 4830 2510
DMacks (talk) 21:13, 24 February 2017 (UTC)
Sandboxing for {{decimal cell}}...
ΔΔG* (kcal) k1/k2 (273 K) k1/k2 (298 K) k1/k2 (323 K)
1.0 6
 .37 5
 .46 4
 .78
2.0 40
 .6 29
 .8 22
 .9
3.0 259 162 109
4.0 1650 886 524
5.0 10500 4830 2510
DMacks (talk) 23:47, 24 February 2017 (UTC)
@Boghog: new template for your enjoyment:) DMacks (talk) 05:54, 25 February 2017 (UTC)
Thanks DMacks! {{decimal cell}} is really cool. Decimal alignment in tables has been really painful to implement and your new template is a much more elegant solution. Boghog (talk) 06:05, 25 February 2017 (UTC)
Since this template would generally be useful, I added {{decimal cell}} to Help:Table in this edit. Boghog (talk) 06:33, 25 February 2017 (UTC)
You're welcome! And thanks for mentioning it on the help page. DMacks (talk) 07:41, 25 February 2017 (UTC)
I just discovered {{0}}. Which is not to say that it is better, I like the new {{decimal cell}}. Any sorting effects? -DePiep (talk) 09:48, 25 February 2017 (UTC)
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)
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)
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:
  273 K   298 K   323 K
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)
...or just use a better grapher altogether...
{{Graph:Chart}} does have some interesting limitations in text formatting and grid-spacing. DMacks (talk) 22:54, 26 February 2017 (UTC)
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)
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
is a weird mix of asterisk (as prefix) and double-dagger. DMacks (talk) 03:24, 27 February 2017 (UTC)
And Energy profile (chemistry) uses ΔG≠ in many of its images. Yuck. DMacks (talk) 04:26, 27 February 2017 (UTC)
Won't this be a linear graph if a log scale is used for the y axis? EdChem (talk) 04:53, 27 February 2017 (UTC)

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)

Possibly related: This concept is mentioned at the psudeo-orphan article Dynamic kinetic resolution in asymmetric synthesis --Project Osprey (talk) 11:10, 3 March 2017 (UTC)

RFC of interest to this project.

See Talk:Chemistry#RFC on the inclusion of a particular passage in the lead of this article. Please contribute if you have an opinion. Thanks. --Jayron32 02:52, 4 March 2017 (UTC)

Proposed merge of lyotropic articles

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)

if noone shows up I create the redirect tomorrow, which is not controversial (I hope).--Alexmar983 (talk) 17:07, 3 March 2017 (UTC)
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)
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)
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)

Comprehensive descriptive chemistry books

Are these still published?

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.
There remains plenty of content to be transferred from the classic books to Wikipedia. --Smokefoot (talk) 05:25, 7 March 2017 (UTC)

Typography for radical

Do we have a preferred symbol for the dot? Bullet, either regular or superscript (H• or H•)? The · entity (H· or H·)? I ask because at Photopolymer#Free radical mechanism, User:Cedar101 is using LaTeX and appears to use superscript period which looks much too small. DMacks (talk) 15:14, 2 March 2017 (UTC)

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)
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)
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)

Use roman type for the symbols for chemical compounds.

ACS Style Guide: Effective Communication of Scientific Information,
3rd ed. (2006), edited by Anne M. Coghill and Lorrin R. Garson

ACS provides official LaTeX style package: see http://pubs.acs.org/page/4authors/submission/tex.html. In this links, the fonts of mhchem are default serif fonts. -- Cedar101 (talk) 14:30, 4 March 2017 (UTC)
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)
To use sans-serif font, simply add \mathsf. For example, see equations in Commons:Special:WhatLinksHere/Template:Use TeX. Mediawiki is dedicated to Wikimedia project, and its chemistry features is for all editors. -- Cedar101 (talk) 04:29, 7 March 2017 (UTC)
Trying out the dot with the math chem tags and sansserif: Matches inline text better but is still big on the letter and small on the dot. Graeme Bartlett (talk) 12:33, 8 March 2017 (UTC)
There is one way to use \scriptstyle for smaller inline equation, and use \bullet (e.g. ). -- Cedar101 (talk) 00:30, 9 March 2017 (UTC)

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)

1. I created the category FWIW.
2. {{Reactionbox}} has 171 tc's now.
3. To be reengineered later on. -DePiep (talk) 23:46, 11 March 2017 (UTC)

TfD of interest

I came across Template:Anachem Award Recipients after writing an article about someone who won the award. Is this award notable enough to need a navbox? Opinions welcome here. Thanks. Opabinia regalis (talk) 06:38, 18 March 2017 (UTC)

Subscripts/Superscript in chemical formulas

Would you consider edits like [2] or [3] to be good things?

Meaning changing (a)

H3O+(aq) + OH−(aq) ⇌ H2O(l) + H2O(l)

to

H3O+
(aq) + OH−
(aq) ⇌ H2O(l) + H2O(l)

or changing (b)

HSO3− ⇌ H+ + SO32−

to

HSO−
3 ⇌ H+ + SO2−
3

Headbomb {talk / contribs / physics / books} 21:18, 7 March 2017 (UTC)

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)
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)
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)
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)
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)
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)

This change should affect {{chem}}, which aligns things when they shouldn't be. Headbomb {talk / contribs / physics / books} 03:59, 8 March 2017 (UTC)

{{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)
<chem> works like {{chem}}. -- Cedar101 (talk) 10:09, 8 March 2017 (UTC)
Markup Renders as 
<chem>HSO3^- <=> {H+} + SO3^2-</chem>

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)
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)
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•−
  • Headbomb, maybe a wider discussion first, encompassing all templates etc.? RfC maybe, or into a MOS? -DePiep (talk) 09:39, 8 March 2017 (UTC)
Well, this is the wider discussion. Headbomb {talk / contribs / physics / books} 11:56, 8 March 2017 (UTC)
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)
  • 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    . --Jayron32 13:17, 8 March 2017 (UTC)
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)
  • 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)
{{Chem2}} uses stacked too (the {{su}} was copied from {{chem}}:
Markup Renders as 
{{chem2|HSO3- <-> H+ + SO3(2-)}}

HSO−3 ⇌ H+ + SO2−3 

{{chem2|[[Bisulfite|HSO3-]] <-> H+ + [[sulfite|SO3(2-)]]}}

HSO−3 ⇌ H+ + SO2−3

  • Christian75 (talk) 13:05, 14 March 2017 (UTC)
  • Other points to consider for any change:
{{Chem}} has this notion wrt COINS and references. Such a restriction should be expelled.
In good webpage/HTML habit, a copy/paste should keep the essential feature (while the sup/sub may be lost). -DePiep (talk) 17:00, 18 March 2017 (UTC)
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)
"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)

Uncontroversial merge

Any chance someone with the interest and know-how could complete the apparently uncontroversial merge of -oic acid and Carboxylic acid? Thanks a bunch, and happy editing! Ajpolino (talk) 03:38, 17 March 2017 (UTC)

 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)

WP:CHEMISTRY/WP:CHEMICALS shorcut updated

Note that per this RFC, the shortcuts to WP:CHEMISTRY/WP:CHEMICALS have been updated.

Old discussions have had their shortcuts updated already. If I have made a mistake during an update, feel free to revert. Headbomb {talk / contribs / physics / books} 15:57, 23 March 2017 (UTC)

Shortcuts, revisited

Strong and clear consensus for Option 1---
  • Re-target WP:CHEM to point to WP:CHEMISTRY.
  • Re-target WP:CHEMS to point to WP:CHEMICALS.
  • Point WP:CHM towards a dab page.
  • Use bot cleanup to retroactively enforce the new convention, so that the old links still point to their intended target.Winged Blades Godric 04:56, 19 March 2017 (UTC)

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.

What should be do about the chemistry project related shortcuts? Headbomb {talk / contribs / physics / books} 16:09, 14 February 2017 (UTC)

The issue

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

We also have the following redirect to WP:CHEMICALS

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.
  • c) We do option 1) as well. We 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.

There's also option 3

  • 3) Do nothing.

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.

Those who already have contributed here: @Sizeofint, Bombhead, R8R, YBG, Sandbh, and Project Osprey: pinged. -DePiep (talk) 08:26, 15 February 2017 (UTC)

!Vote

  • option 1 > 2c > 2b > 2a >>>>>>>>>>> 3. In my mind, it's clear that CHEM = Chemistry and CHEMS = Chemical, and that CHM is fairly WTF-y. Headbomb {talk / contribs / physics / books} 16:09, 14 February 2017 (UTC)
  • 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)
  • Option 1 Oppose all Option 4: 'CHEMY', and CHEM to dabpage. see below. Nice dab addition. -DePiep (talk) 16:42, 14 February 2017 (UTC)
Though I'd prefer WP:CHEMY, because WP:CHEM is ambiguous still (needs a reminding). -DePiep (talk) 19:12, 14 February 2017 (UTC)
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)
Option 4 for me then. -DePiep (talk) 22:18, 15 February 2017 (UTC)
  • Option 1, the best by far - unless there is a possibility of combining the two projects. YBG (talk) 18:59, 14 February 2017 (UTC)
  • Option 1 is a no-brainer. Sandbh (talk) 06:22, 15 February 2017 (UTC)
You mean to say: good for if you have no brain then? To me, it is a headache. Seriously. The shortcut is ambivalent. -DePiep (talk) 22:20, 15 February 2017 (UTC)
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)
  • 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)
  • Just swap CHEMS and CHEM. I don't see a reason to redirect CHM. Sizeofint (talk) 03:32, 16 February 2017 (UTC)
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)
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)
OK, thanks. Any next should be in #Discussion I'd say. -DePiep (talk) 01:57, 25 February 2017 (UTC)
  • 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)
  • 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)
  • 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)
  • Option 1 seems to be by far the most sensible option. Double sharp (talk) 04:57, 22 February 2017 (UTC)
  • 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)
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)
  • Option 1 is better than the status quo, which is not great. SemanticMantis (talk) 15:38, 28 February 2017 (UTC)
  • 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)
  • Option 1 as the most intuitive and logical shortcut. --Joshualouie711talk 15:49, 11 March 2017 (UTC)

Discussion

  • 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)
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)
For most people 'chem' is short for chemistry, and 'chems' is short for chemicals. Both projects will have {{redirect}} notices for those who accidental misuses the wrong one, but the proposed retargeting would follow the principle of least astonishment. Having additional shortcuts has no bearing on what should be done with these two. Headbomb {talk / contribs / physics / books} 12:54, 15 February 2017 (UTC)
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)
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)
"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)
  • BTW, I've made some 15k edits with {{Chembox}}. To me, Chem is a chemical. -DePiep (talk) 22:15, 15 February 2017 (UTC)
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)
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)
  • 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)
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)
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:
. -DePiep (talk) 22:26, 6 March 2017 (UTC)
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.

BOTREQ

I have retargeted the pages and filed the WP:BOTREQ, replacing those manually. There are way too many false positive to handle by bot. If I've made a mistake that pops up on your watchlist, feel free to revert. Let's use WP:CHEMISTRY and WP:CHEMICALS in the meantime. Headbomb {talk / contribs / physics / books} 14:36, 23 March 2017 (UTC)

Should be done now. I'll review WP:CHM next, although I don't think we need to formally convert that to a dab. Headbomb {talk / contribs / physics / books} 15:33, 23 March 2017 (UTC)
Done. WP:CHM marked as deprecated. If I have been a mistake anywhere, feel free to revert/fix. Headbomb {talk / contribs / physics / books} 16:00, 23 March 2017 (UTC)

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)

One real question I wish could be answered is why we say quaternary instead of quartary. Any reason?? Georgia guy (talk) 23:13, 21 February 2017 (UTC)
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)
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)
Substituted? I think the [Goldbook] would agree (?) --Project Osprey (talk) 10:56, 22 February 2017 (UTC)
Hi, Carey & Sundberg use the imho correct term 'degree of substitution' (in german 'Substitutionsgrad') only once in their book ([4]). The substituent can be alkyl or aryl ([5]), 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)

Here are the meanings of primary, secondary, tertiary and quaternary, from the OED:

  1. "Of the first order in time or temporal sequence; earliest, primitive, original."
  2. "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."
  3. "Of, in, or belonging to the third order, rank, degree, class, or category; third."
  4. "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.)"

Google translate says the Polish "rzędowość" = order, as per the first mentioned meanings in 1 and 3, above. Sandbh (talk) 03:09, 24 March 2017 (UTC)

More class projects

These all popped up in the CS1 maintenance categories looking related to each other, so there may be more:

Without too much investigation, they all appear to be in a documented course at Wikipedia:Wiki Ed/University of California, Berkeley/Environmental Justice Section 103 (Spring 2017). --Izno (talk) 10:59, 18 March 2017 (UTC)

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)
The first three all would be the same topic, and I agree that none of them seem suitable as Graeme notes. DMacks (talk) 07:12, 24 March 2017 (UTC)
Although I support deleting the lot, often it is easier to just make turn these narrow homework projects into redirects. --Smokefoot (talk) 13:47, 24 March 2017 (UTC)
There is apparently another class working on the articles below (and perhaps others). Discussion at Wikipedia:Education_noticeboard/Incidents#Chemistry_class_maybe. -- Ed (Edgar181) 13:09, 18 March 2017 (UTC)

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. ISSN 0021-9584.
  • 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. ISSN 0021-9584.
  • 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. ISSN 0021-9584.

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)

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)
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)
To my mind most of the problems we have stem from 3 issues:
  1. 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.
  2. Wrong content: we want general information of a broad topic but we always seem to get detailed information on a narrow topic.
  3. 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)

note

Wikipedia talk:WikiProject Medicine#Wikitext syntax change for chemicals--Ozzie10aaaa (talk) 01:20, 6 April 2017 (UTC)

Upcoming "420 collaboration"

You are invited to participate in the upcoming

"420 collaboration",

which is being held from Saturday, April 15 to Sunday, April 30, and especially on April 20, 2017!

The purpose of the collaboration, which is being organized by WikiProject Cannabis, is to create and improve cannabis-related content at Wikipedia and other Wikimedia projects in a variety of fields, including: culture, health, hemp, history, medicine, politics, and religion.

For more information about this campaign, and to learn how you can help improve Wikipedia, please visit the "420 collaboration" page.

---Another Believer (Talk) 17:26, 10 April 2017 (UTC)

Unclear article-names

The following two articles have names that are unclear about what their specific content is:

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)

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)

Copyright issue with an image, can someone please quickly check two literature references?

I have Wikipedia:Media copyright questions#File:C3cs35486e-f1.gif posted at the media copyright questions page about the image File:C3cs35486e-f1.gif which is included on the artificial enzyme page. It was uploaded as "own work" by Wiki nju001 in 2015. The information in the image is seen in this supplementary data file from doi:10.1039/C3CS35486E, and the image has been reproduced with permission from the RSC in a book attributing the source as doi:10.1039/C5QI00240K. This second paper in Inorg. Chem. Front. was made available online four days before the upload. The uploader has not edited since that day. Would someone please establish if either of these papers actually includes the image? The image is hosted at commons but may have been uploaded to en-WP first. Either way, it seems to me that the image is a copyvio and, if not, the attribution in the article is inadequate. Help / an opinion from an admin (en-WP or (ideally) en-WP and commons) would be appreciated. Thanks. EdChem (talk) 00:04, 19 April 2017 (UTC)

Heptamethine dyes

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)

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)

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)

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)
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)

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)

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 Beetstra T C 16:29, 29 April 2017 (UTC)
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)
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)

References

  1. ^ 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.
  2. ^ Bruckner, Reinhard (2001). "13.3.4 Alkenylation and Arylation of Copper Acetylides". Advanced Organic Chemistry: Reaction Mechanisms. Academic Press. pp. 535–538.
  3. ^ [1]
Great catches, maybe my internal guidelines are messed up. Bu4N+C2R would indeed be useful reagents. --Smokefoot (talk) 12:48, 30 April 2017 (UTC)
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)
@Smokefoot: Here's a fun one: an atrane[1][2] intermediate. DMacks (talk) 04:02, 1 May 2017 (UTC)

References

  1. ^ secondary ref: Vedejs, Edwin; Denmark, Scott E. (2016). Lewis Base Catalysis in Organic Synthesis. Vol. 2. Wiley. p. 262. ISBN 9783527336180.
  2. ^ ...which cites: doi:10.1021/jo9012332

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)

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)
Thanks for all the input, the main thing is that I need to get started, everyone is welcome to revert or do their bit.--Smokefoot (talk) 12:48, 30 April 2017 (UTC)

Alkynation vs alkynylation

OK, in the process of reworking acetylide, I moved alkynation (sounds real enough, but forty some hits on CAS) to alkynylation, which has thousands of hits on CAS. I assume they are the same thing. --Smokefoot (talk) 17:05, 30 April 2017 (UTC)

Cyclic microcellular foaming

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.

The authors User:Questpr and User:Gandhi.iitdelhi also created Nucleation in microcellular foaming

I try to improve the categorization of the related files on commons.--Alexmar983 (talk) 15:29, 1 May 2017 (UTC)

Carbometalation

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)

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

From Chemical Reviews 1990, 90, 879-933.

So the experts think that it is one l. --Smokefoot (talk) 20:22, 2 May 2017 (UTC)

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)
OK I just changes all of them that were not part of an article's title
Thank you! Double sharp (talk) 02:48, 3 May 2017 (UTC)
Illustration of silylmetalation in the carbometalation article

While we are on the carbometalation article, I noticed the image File:Silylmetalation.png, shown at right and uploaded by V8rik in 2007. The image has, in red:

  • 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)

EU classification (DSD) will soon cease to be in force

Please see Wikipedia talk:Chemical infobox#DSD data but no GHS data for more details and task that need to be done. --Leyo 22:17, 8 May 2017 (UTC)

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)

To me that is still a strange thing to do. I use the identifiers to get to more data (especially if I don't trust physical data on Wikipedia). I'd prefer that in the top. We're (still) not a reliable source. --Dirk Beetstra T C 16:10, 8 May 2017 (UTC)?
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)
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 Beetstra T C 17:15, 8 May 2017 (UTC)
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)
Tracked in Phabricator
Task T107768
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)
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)
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 Beetstra T C 03:08, 10 May 2017 (UTC)
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)
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)
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)
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)

Nascent_hydrogen

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)

Yes, delete it, the names in the chembox are a bit of a give-away as to who put it there --Project Osprey (talk) 10:00, 5 May 2017 (UTC)
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)
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)

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)

  • 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)
@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)
Thanks for the explanation, VQuakr. Hydrogen embrittlement is certainly a problem, though I agree it can be described / explained without invoking the nascent state. EdChem (talk) 17:32, 14 May 2017 (UTC)
  • 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)
  • 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)
  • Nascent state (chemistry) still has the same old rubbish in it that used to be in nascent hydrogen. Would someone help out?! 158.93.6.11 (talk) 22:49, 6 May 2017 (UTC)
 Done I think I've got it historically-focused now. VQuakr (talk) 23:02, 6 May 2017 (UTC)
Well done. Now you have two parallel articles on the same subject, a concept of only historical interest. 158.93.6.11 (talk) 14:50, 7 May 2017 (UTC)
Ok, then we are agreed to merge these articles into Nascent state (chemistry)??--Smokefoot (talk) 15:08, 7 May 2017 (UTC)
Fine with me. I'm not hung up on the title. 158.93.6.11 (talk) 15:47, 7 May 2017 (UTC)
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)
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)

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

  1. at least two major web browser that I was checking, were auto-splitting long words containing hyphens without problems,
  2. Wikipedia is served as html(5) doctype, so the <wbr> usage should be without problems as well.

—Mykhal (talk) 23:53, 6 May 2017 (UTC)

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)
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)
I did not look at your edits. You say you did not even use AWB? -DePiep (talk) 20:47, 8 May 2017 (UTC)
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)
Mykhal, I can categorise every article that has a <br> in |IUPACName=. Would that help? -DePiep (talk) 21:27, 8 May 2017 (UTC)
There are not so many such articles based on insource:/IUPACName *=[^\|]{3,50}\<br/. Most of the hits are false-positives. --Leyo 22:04, 8 May 2017 (UTC)
Thanks for the regex. Your search gave 112 hits. With insource:/IUPACName *= *[^\|]{3,50}\< *br I got 499 hits. (But why false positives like Antimony tribromide btw?). -DePiep (talk) 21:44, 9 May 2017 (UTC)
The closing / is missing. --Leyo 07:39, 10 May 2017 (UTC)
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)

Chemicals derived from petroleum - request

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)

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 K, Arpe HJ (2003). Industrial Organic Chemistry Important Raw Materials and Intermediates (3rd ed.). Weinheim: Wiley-VCH. ISBN 978-3-527-61459-2. Boghog (talk) 17:52, 15 May 2017 (UTC)
Or: Kirk-Othmer Encyclopedia of Chemical Technology, 27 Volume Set, 5th Edition (2007) ISBN 978-0-471-48494-3 and Ullmann's Encyclopedia of Industrial Chemistry. JimRenge (talk) 18:05, 15 May 2017 (UTC)
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