Latest comment: 10 years ago163 comments10 people in discussion
Please see Talk:Alkene#Definition for what should be a very simple question... is dichlorodifluoroethylene an alkene? Several of our articles suggest or assume that it is. This isn't what I learned in high school! But I could be wrong. Simple question, it should have a quick simple answer I hope. (But I could be wrong there too.)
Periodically editors "get religion" about following IUPAC or some set of rules or guidelines. These instincts are well intentioned, but we dont follow any of them very carefully. Instead we are dedicated to common usage and everyday nomenclature. We strive to keep things non-opaque. Students who are just learning chemistry often come to Wikipedia with strong views on nomenclature, but people who do chemistry use more flexible language. To me, dichlorodifluoroethylene is an alkene.--Smokefoot (talk) 14:38, 30 December 2013 (UTC)
A very important contribution. This hits a number of nails right on the head.
We are a general encyclopedia. We want to make our information available to the general reader. It's fine to have articles that go into details that only a specialist will understand, but the priority is to make accurate information generally available.
I appreciate your viewpoint. But for Wikipedia to call dichlorodifluoroethylene an alkene, or even to imply that it is one, without a clear qualification that this is an esoteric usage and contrary to the IUPAC definition is, quite frankly, misinformation. Andrewa (talk) 15:46, 30 December 2013 (UTC)
Unsaturated chlorofluorocarbon might be a safer descriptor. Frankly though, this would be the first time I'd have encountered an ethylene that wasn't an alkene (I would certainly expect it to react like an alkene). Project Osprey (talk) 22:17, 30 December 2013 (UTC)
Exactly. Is a substituted alkene an alkene? Language is complicated. A near miss is still a miss, but a near hit is not a hit. Andrewa (talk) 23:07, 30 December 2013 (UTC)
WIkipedia Chemistry project does not assign IUPAC or any professional society control over our language. I think that most chemistry editors are mindful of IUPAC, but in Wikipedia not following IUPAC is not incorrect, and following IUPAC often gets pretty weird. So we play it by ear and rely on consensus by a broad collection of chemically savvy editors. Again, for the great majority of us, allyl alcohol and ethylene are alkenes. The main point really though is that most of us are highly focused on content, and nomenclature purification campaigns distract from readers picking up on the content which is challenging. People learning chemistry often focus on nomenclature because it is easy to learn and kinda fun, but the heart of the topic is much deeper and we are wary (and weary) of others suddently imposing their insights on "the way it should be." Hope this perspective helps. We have this discussion every year, usually led by someone learning chemistry, which is cool. --Smokefoot (talk) 23:35, 30 December 2013 (UTC)
OK... and going by consensus is good (see WP:creed#consensus). And thanks for bearing with me, and I am certainly learning some chemistry.
But I'm unconvinced that this is working as well as it might. Perhaps the topic comes up regularly because there are some actual problems. The WikiProject members are not a general audience, and a general encyclopedia is written for this general audience.
Perhaps it is well not to slavishly follow the IUPAC definitions. I'm unconvinced, I think we may still even end up there (and hope that if we do it might be on terms that make these annual discussions at least a little rarer).
But I do think the IUPAC definitions need to receive at least a little more recognition than currently, even if only to say explicitly that we reject them and why. I can't see how that would make the topic opaque. On the contrary, I think it would make it less so, and that this is overdue. But I appreciate that this may be a perennial proposal. Can you easily provide any links to any of these previous discussions? Andrewa (talk) 00:18, 31 December 2013 (UTC)
The definition of an alkene per se is NOT the perennial question. What is perennial or at least periodic is some relatively strict interpretation of some nomenclature rules. Nomenclature purification campaigns are not bad things but they can frustrating/distracting to editors here who are wrestling to explain more thorny chemical topics. To reassure IUPAC enthusiasts, Wikipedia Chemistry is steadily headed towards ever more standardized nomenclature. We however are mindful of our diverse readership and the need reins in strict nomenclature lest inexperienced readers assume that IUPACs definitions have perfect currency in the workplace. Here are three titles from the distinguished series Chemical Reviews, solid WP:SECONDARY sources. One can be pretty sure that these authors use "alkene" far more broadly than IUPAC recommends (bolding added by me):
Harvey, D. F., Sigano, D. M., "Carbene-Alkyne-Alkene Cyclization Reactions", Chemical Reviews 1996, 96, 271;http://dx.doi.org/10.1021/cr950010w
Willis, M. C., "Transition Metal Catalyzed Alkene and Alkyne Hydroacylation", Chemical Reviews 2009, 110, 725; http://dx.doi.org/10.1021/cr900096x
McDonald, R. I., Liu, G., Stahl, S. S., "Palladium(II)-Catalyzed Alkene Functionalization via Nucleopalladation: Stereochemical Pathways and Enantioselective Catalytic Applications", Chemical Reviews 2011, 111, 2981. http://dx.doi.org/10.1021/cr100371y
Why can one be pretty sure that these authors use "alkene" far more broadly than IUPAC recommends? That's a key point. You and others are quite confident of this general usage, and yet the evidence so far is next to nothing. You simply give the names and authors of the texts, and seem so confident that they adopt this usage that I'm not altogether sure that you've checked. Now that is technically verifiable, but I don't think it's terribly fair, and I doubt many editors (yourselves included) would accept such evidence from me. If I had a relevant text and was consulting it, I'd give you the relevant quote and the page number. Is that a reasonable expectation?
Even then we won't be completely out of the woods, in that examples don't prove much. They do establish that some people follow this usage, but what we want to determine is, what do most people follow? That's a much harder question. But standard texts are a good start.
I'm still astounded that the IUPAC is held in such low regard. If only the IAU were so toothless, then my Save the planet Pluto T shirt would be unnecessary. Alas, my primary school students now get marked wrong if they call Pluto a planet. But apparently, if they were to call carbon tet (CCl4) a hydrocarbon, I'd have to give them the benefit of the doubt. Science is changing. Andrewa (talk) 03:52, 31 December 2013 (UTC)
"We" don't hold IUPAC in low regard. IUPAC is a helpful recommender of nomenclature and definitions staffed by dedicated professionals. But chemistry has such deep historical roots that terminology is encumbered by tradition. For such reasons, few Wiki editors emphasize nomenclature.
Regarding the proof that the above articles basically ignore the IUPAC recommendations, I guess you'd have to trust us. But here is some excepts, if you can trust me:
For the Wills Chem. Review, the first figure, which illustrates the hydroacylation of alkenes, shows 4-pentenealdehyde as the alkene, which cyclizes to cyclopentanone.
From the initial section of Stahl's Chem. Review "The Wacker process, involving the oxidation of ethylene to acetaldehyde, is the most prominent example of a catalytic reaction that proceeds via oxypalladation of an alkene." (note ethylene = alkene) I added hyperlinks to the articles (if your institution have a subscription).
So you can see why it would be irresponsible for editors in this project to advise readers to turn to IUPAC for a definition of alkene and a host of other time-honored (or time encrusted?) terms. BTW, the situation is the same for alkynes. Sorry to disappoint you with our backward ways. Nomenclature aside, the technical parts are pretty interesting! --Smokefoot (talk) 05:16, 31 December 2013 (UTC)
I think, that if you play it to the letter, it is not a hydrocarbon, and probably calling a non-hydrocarbon an alkene/olefin then might be a slight stretch of the rules (and the rules differ on some sides). But in the typical reactivity, it still has reactivity similar to an alkene/olefin (like tetrafluoroethylene has as well). I therefore think that the classification as an alkene/olefin is important.
A too strict application of the rules here has implications throughout - would it improve the understanding if Sex and the City would use the probably more IUPAC correct 'sleep[ing] with .. a recreational 1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)phenylsulfonyl]-4-methylpiperazine user'? I think not. Does it improve the understanding what dichlorodifluoroethylene (or better tetrafluoroethylene) can do by calling it an alkene/olefin - I think so, even to the lay reader. We however should avoid to confuse the lay reader with the subtleties in differences between alkenes, olefins and compounds with a C-C-double-bond .. what is 1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)phenylsulfonyl]-4-methylpiperazine? An amine, an ether, an amide, a sulfone, an aromatic compound, an alkene, ketone, imine, or an alkane .. ? --Dirk BeetstraTC06:32, 31 December 2013 (UTC)
Logic, trust, sources, OR
Thanks for the replies above. I think this is progress.
It's not a matter of logic or trust. It's a matter of Wikipedia policies. No WikiProject is exempt from these. If I seem to be one of those who periodically... get religion,[3] that religion (in my case at least) is Wikipedia not chemistry.
IUPAC still appears to me to be an excellent source in terms of WP:cite. Whether you convince me that IUPAC is often wrong (for Wikipedia's purposes at least, that's all I care about here) is (in the long term at least, see below) irrelevant. I'm no more citeable than you are (or to be precise, even less citeable on chemistry, and I'm happy to concede and assume that). It's not splitting hairs: If IUPAC says that a dichlorodifluoroethylene is not an alkene, and we say or even assume or imply that it is, we need a citation, otherwise we've strayed (like most of the above) into WP:OR, and that's one of our hot buttons.
(Let me make one subtle but important point here: WP:OR is not a sin on talk pages, in my (perhaps radical) opinion. The first step towards being encyclopedic is to be accurate. As an intermediate step towards improving an article, original research is perhaps inevitable, and discussing that research here is good. We can't write about what we don't understand (ideally). But by the time that research reaches the article, it needs (ideally) to be supported by reliable secondary sources rather than just by our own understanding.)
But I am beginning to understand the problem a little more, I think. Is it fair to say that the IUPAC Gold Book does not really stipulate or define anything, but merely recommends? (Or is it more complicated than that?)
This seems to be a recurring theme above, and is something that might well take a layperson by surprise. It certainly did me. Andrewa (talk) 20:35, 31 December 2013 (UTC)
It is indeed not a matter of logic .. unfortunately. But then, this is not mathematics.
The sources are contradictory here, IUPAC is not the 'final source' or 'only source' of data (here are twois one ACS (peer reviewed) articles talking about 'perfluoroalkenes': doi:10.1021/jp0602427 and doi:10.1021/jp0602427 - are those sources wrong because it does not follow IUPAC?). IUPAC is a recommendation for nomenclature: it names the compound 'dichlordifluoroethylene', and as IUPAC will tell you, ethylene, the base where the name of the compound is built on, is an olefin, an alkene. You see where IUPAC is there even contradicting itself - IUPAC is saying that it is not an olefin/alkene, but in its nomenclature it is basing its naming rule on just that olefin/alkene, which they say it isn't. The world is not so black and white. And that is the whole problem with naming (and even categorisation) of compounds. This has nothing to do with trusting our understanding of the compound, this may have something to do with trusting us to understand the chemistry; this has nothing to do with original research, it has to do with understanding the chemical nomenclature, it has not even anything to do with sources - naming of compounds can not be sourced, the only thing we have is a 'recommendation' of the IUPAC. If anything, the article on alkene could write a sentence or two about the 'rules' of naming something an alkene/olefin, and how common usage (or even those same rules from the rulebook) 'contradicts' that (I wonder actually how you would call tetrafluoroethylene if you insist on the rule that it is not an alkene/olefin, and hence the naming can not be based on the naming scheme of an alkene/olefin). --Dirk BeetstraTC21:33, 31 December 2013 (UTC)
Again with fear and trembling, I think I need to be a bit more assertive here. This misrepresents much of what I am saying, and fails to address the questions I asked. I don't for example insist on the rule that it is not an alkene/olefin, and hence the naming can not be based on the naming scheme of an alkene/olefin. That is ridiculous, and misquotes me on almost every proposition it asserts.
Agree that categorisation and classification have pitfalls, in all fields probably. I have another T shirt that says Hornbostel Sux and has a little jingle that most of my fellow percussionists find amusing, see my personal webspace and also the classification of percussion article here.
But it raises one fascinating and important point, quite succinctly: naming of compounds can not be sourced. Can I ask whether anyone else agrees or disagrees with this? I think it might be very helpful, either way. Andrewa (talk) 22:47, 31 December 2013 (UTC)
At least not systematic names. I think that you would find it amusing, as I do, that the project rejects IUPAC publications as an authoritative source for IUPAC systematic names. It is quite a topsy-turvy situation, such as one may expect in wonderland. Plasmic Physics (talk) 23:05, 31 December 2013 (UTC)
Yes, there's a sense in which systematic names don't individually need sources, provided we (somewhere) cite our sources for the system and then follow it. That still in a sense sources the name. Is that the only problem you see?
I don't think that the situation is quite topsy-turvy. But the more I dig here, the deeper the hole becomes.
But I do think there's the possibility of progress, or I wouldn't waste everyone's time. Mine included.
They seem to be acclimated to the contrary. A while ago, as part of a mission, which I took upon myself to update and maintain chemboxes, I inserted and made alterations to systematic names in the appropriate fields of the chemboxes. Not long after the start of the mission, the names started to be bombarded with 'citation needed' templates for various supposed reasons. Through the years, as I have attempted different sources, each one was in turn rejected individually, or as a member of a defined class. Eventually, no possible sources remained, yet the templates remained also. So I'm left with the riddle: how to cite the uncitable. I've tried to generate solutions to this very dilemma, but I'm not as eloquent or skilled at debating as yourself. Rather than cooperatively working toward a solution that satisfies all, it was found much easier to sweep the issue under the carpet altogether. Since the issue appeared to be propagated by myself, it was I that had to be eliminated. That was accomplished with a topic ban, a ban from editing any chemboxes whatsoever. Plasmic Physics (talk) 02:40, 1 January 2014 (UTC)
I've looked at that topic ban. I don't want to go into the rights and wrongs of it, other than to say three things: 1) I can see faults on both sides (sorry); 2) Wikipedia is not about being fair to contributors, but purely about using them to build the best encyclopedia that we can (that's not to condone abuse, just to put it into context); 3) I'm most impressed by the way you have hung in there despite the ban. That's the right attitude.
And I'm glad you raised it here, but purely because it's good for me to know this history. But now that I do, I'd strongly recommend both sides to let it drop, and focus on the current issues. It doesn't matter who has the last word. Just drop it. Andrewa (talk) 21:53, 1 January 2014 (UTC)
Andrewa - sorry, the 'you' was meant plural here - maybe I should have worded that differently a bit (use 'one' maybe in stead of 'you'). Basically, tetrafluoroethylene and dichlorodifluoroethylene are alkenes/olefins, just as acetic acid does have a part that is an alkane. Some, even very simple, compounds defeat all logic in namegiving - is carbon tetrachloride an alkane? Is it even an organic compound? If you extend that to chloroacetic acid .. is it an acid or a haloalkane (organochloro compound) .. or even an alkane .. (I extended this hyperbolic above). I think that a good reason to not to adhere to IUPAC too much is that we are writing an encyclopedia for the reader, the public - and understanding the chemistry behind a compound is sometimes more important than whether it is or is, technically, belonging in a certain group of compounds (and all I would suggest that the 'group-page' then has that distinguished - that is the type of improvement that may be needed and for which a lay-eye on a subject is important - you've now in a way alerted us to that, thanks!).
Much of the naming in itself is a form of original research based on a recommendation. It is, as Plasmic Physics suggests, a difficult and contentious area. Some systematic names are common ground, but quite some are vague or can only be supported by a recommendation. They sometimes get so esoteric that even the peer-reviewed literature is ignoring (sometimes completely) the recommendations of IUPAC as, albeit systematic, it does not help even the specialist reader to understand what one is talking about (and it is also true for some other systematic data like the InChI and the SMILES - they generally work fine, but there are also there borderline cases which misrepresent the subject - I think that some complex salts still have 'problems' in InChI and can be 'correctly' represented in different ways without violating 'rules'). The fields are there in the chemboxes, the data also sometimes gets expanded in the prose, but it is, often, a tricky field. Again, our focus should be understanding for the reader.
Plasmic Physics - your remarks show that you still don't understand why you were topic-banned from editing chemboxes whatsoever. Wikipedia is not a battleground. --Dirk BeetstraTC07:05, 1 January 2014 (UTC)
It may be that I don't understand, but that only reveals the failure of the topic ban to adequately inform me of what change is required on my part, other than adhering to the ban itself. If Wikipedia is not a battleground, then why am I having to defend my person, and my positions? Plasmic Physics (talk) 13:33, 1 January 2014 (UTC)
Or it reveals that you don't understand that the actions you were undertaking would either need proper discussion/consensus before being done, did not need to be done, or should be done with extreme care, and that if one subject stirs up too much dust, that some other related subject likely is also going to stir up similar dust. What I however do seem to notice is that the topic ban has been rather effective in reducing the dramah from your edits (and that that is coming from someone who has a grudge against bans and their issuing bodies should say something). --Dirk BeetstraTC13:43, 1 January 2014 (UTC)
I'm going to try to take a step back again. I think we've identified some ongoing but solvable issues.
I'm disappointed that I had almost no response to the question I asked above regarding the sourcing of names for chemical compounds. So at the risk of jumping to a solution, let's try another tack.
(1) Wikipedia is not a textbook. That's what Wikibooks is for. Wikipedia is written for a general audience. That doesn't mean that we shouldn't be useful to a more sophisticated audience as well, I hope we are. But we shouldn't be confusing to the naive either. We must clarify things that would not be necessary in a textbook, or data book, or academic paper. This includes (but is not only) avoiding professional jargon.
(3) Even if my opinion (2) above is agreed, that doesn't mean that we blindly adopt every IUPAC recommendation. But it does mean that whenever we depart from those recommendations, we need to explain and justify this (generally by footnotes, and always by citing a relevant source).
(4) Adoption of (1)-(3) above would be a big change of direction, in that it involves a lot of work.
But it seems to me that long term this would result in a correspondingly big improvement in our coverage, particularly of organic and related compounds. Andrewa (talk) 23:15, 1 January 2014 (UTC)
In my experience, Gold Book definitions need to be (a) handled with at least a modicum of caution; and (b) cross-checked against the source materials. For example, Gold Book defines a transition metal as 'An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell. Ergo, Ce, Gd, Th, Pa, U, Np and Cm are transition metals—which they aren't. The source (Red Book, p. 51) says nothing along these lines and instead says: '…the elements of groups 3–12 are the d-block elements. These elements are also commonly referred to as the transition elements, though the elements of group 12 are not always included…' Second example: Gold Book defines a salt as, 'A chemical compound consisting of an assembly of cations and anions.' Red book (p. 61) says, 'This term is taken to mean any compound in which it is possible to identify at least one constituent which is a positive ion or can be classified as electropositive or more electropositive than the other constituents, and at least one constituent which is a negative ion or can be classified as electronegative or more electronegative than the rest of the constitutents.' The two defintitions aren't the same. Gold Book = latter-day concept of a salt as an ionic compound; Red Book also accomodates old-school concept of a pseudo- or covalent salt. (I presume the Red Book defintion was worded that way to encompass the older primary concept of a salt as the product of the reaction of an acid with a base, regardless of the degree of ionicity in said product.) Sandbh (talk) 02:06, 2 January 2014 (UTC)
Agree. The definition of transition metal is particularly controversial, see its talk page.
I'll go further... (1)-(3) are supposed to encourage this checking, by encouraging the consulting and citation of sources that differ from the Gold Book. Andrewa (talk) 07:16, 2 January 2014 (UTC)
This is exactly what we are doing/trying, Andrewa. It does however not mean that we miss things (don't think 'simple' enough ..), did not finish things, should discuss things (should get consensus on things), or did things 'wrong' .. hence, there is no big change in direction nor a lot of new work. --Dirk BeetstraTC05:38, 2 January 2014 (UTC)
Great! I particularly like the exactly (which I assume applies only to (1)-(3)).
But some of the comments further above differ significantly from my (1)-(3). If so (and if we have consensus on them) then (1)-(3) may still offer some useful clarification.
Or alternatively, it may be that we don't have consensus on (1)-(3). Other comments? Particularly, would others like to support (1)-(3)?
Maybe you did not understand. We are doing exactly 1-4 (it is practically the current consensus within the project). We are writing for a general audience, IUPAC gold book is a good reference, we use it to write, but we do need to depart from their recommendations sometimes (quite often actually, per your point 1), and we need to explain that. Since we do 1-3, there is no need to adopt 1-3, and hence there is no big change. --Dirk BeetstraTC08:39, 2 January 2014 (UTC)
I understand what you are claiming, but it doesn't seem to be true. You yourself have just rejected the request for a citation supporting the claim that DDE is an alkene.[4] That is in direct violation of (3). Or didn't I express (3) clearly enough? Andrewa (talk) 12:06, 2 January 2014 (UTC)
Agree that WP:V, as it stands, does not support the current practice of this WikiProject. That's the fundamental problem. Andrewa (talk) 12:06, 2 January 2014 (UTC)
And to tell the truth, I'm having great trouble understanding you. You seemed to support (1)-(3), even saying they were already being followed,[5] I thought. But they were always intended to require a reference whenever the IUPAC recommendation was not followed (that's almost the second clause of (3) verbatim, and the word whenever was even bolded)... such as extending the scope of alkene to include DDE.
But now you're saying [6] that you don't think such a reference is required after all. We seem to be going in circles, and I don't think it's my position that is cyclic. Andrewa (talk) 13:13, 2 January 2014 (UTC)
(as I said elsewhere, my apologies for the confusion - I thought that the definition of 'common knowledge' on Wikipedia was wider than it actually is).
The point is, we need to do it - I am not saying that it is consistently done (I think we are more busy with the really questionable sentences and getting them referenced to bother about the, what we consider, common knowledge). Wikipedia is riddled with {{cn}}/{{fact}}-tags, some staying for years as everyone knows they are 'true' and most are ignored and not filled in (people would probably call me a vandal if I would add those tags throughout in articles .. and not only in chemistry). --Dirk BeetstraTC15:06, 2 January 2014 (UTC)
But I agree wholeheartedly about fact tags and similar. I'd even like to see a behaviour policy that restricted their use. But it's difficult to come up with one. The idea that you must clear at least (say) one such tag for every three you post ignores the fact that some contributors are very good at posting helpful tags, and not necessarily good at clearing them. They are different skill sets. Perhaps a bot that archives the tags (removes them from articles but allows them to be easily flagged manually for automatic reintstatement, or automatically reinstated under some circumstances) whenever those under the care of a Wikiproject reaches some threshold. And/or a behavoural policy that limits the number of tags you can post without editing the corresponding article talk pages... again enforced by a bot that posts a polite message, eventually escalating to a block warning? I might call it hitandrunbot. Dreams... Andrewa (talk) 22:06, 2 January 2014 (UTC)
On proposals that won't happen
@Andrewa: the IUPAC gold book definition of an alkene requires a molecular formula of CnH2n. According to this definition, alkenes cannot contain elements other than carbon and hydrogen. Monomers like vinyl acetate and tetrafluoroethylene which polymerise by processes typical of alkenes (using the broader meaning of the term) are excluded. Styrene is also excluded, yet polystyrene, teflon, and PVA are all commercial products where arguing about the definition of 'alkene' would be a disservice for readers. The Gold book definition allows for cycloalkenes and alkadienes as related terms which do not fall within the meaning of alkene, which is an artificial distinction if you consider the chemistry of these substances, and I don't know what they would call beta-carotene. Does testosterone have secondary alcohol, ketone, and alkene functionalities or should we insist it is an α,β-unsaturated carbonyl in a polycyclic aliphatic alcohol? I know which our readers will understand. Then, what about ethylenetetracarboxylic acid? Not an alkene, or a carboxylic acid, is it, by Gold Book approaches?
The point you are raising reminds me of another unhelpful debate on the organic / inorganic distinction... some definitions insist on classing materials that lack a carbon-hydrogen bond as inorganic, meaning that the acid I just mentioned is inorganic. It means that oxocarbons based on carbon backbones like cyclopropanetrione and ethylenetetracarboxylic dianhydride are inorganic (despite the latter being basically two maleic anhydride molecules, an organic substance, sharing the alkene backbone). Yes, we need to respect reliable sources but we also need to reflect common usage and the solution that most chemists follow is to use restrictive definitions in initial teaching but broaden them with increasing knowledge / understanding (as discussed by Keith Taber, Editor of the RSC journal CERPhere for example). An encyclopedia, however, must reflect the way terms are used and applied in real contexts and focus on key issues for each topic. The term alkene is used in a broad sense that includes cycloalkenes, that includes dienes and beyond, that includes other functional groups and substituents, and which is concerned more with the chemistry of the functionality. Maybe our alkene article needs to draw distinctions between 'alkene' as the series of homologous compounds ethene, propene, 1-butene, ..., 'alkene' the Gold-book acyclic CnH2n, 'alkene' the C=C isolated functionality, and 'alkene' the catch-all term for compounds with this functionality, etc. However, the use of the term in the general encyclopedia might have any of these meanings and this is appropriate because context dictates which is meant, a not uncommon situation with technical terms. Trying to restrict terms to a single meaning in all contexts is not unusual for those without a comprehensive understanding of a topic, but that has not and IMO should not dictate what is done in these cases. EdChem (talk) 03:08, 5 January 2014 (UTC)
Thanks for joining the discussion, and I agree with much of this. But I think you misunderstand my intention completely.
And I appreciate that there have been unhelpful proposals in the past. (And I'd quite like some wikilinks to the archives of the more relevant of these if you have them readily to hand, to save us all from reinventing the wheel.) But please judge my contributions on their merits.
I'm not for one minute trying to restrict terms to a single meaning in all contexts. Just the opposite.
Did you look at my draft lede for the alkene article? [7] It's intended to take exactly the approach you are now recommending, as far as I can see.
(edit conflict)The article lede is just fine (maybe needs more references). The world calls compounds with a carbon-to-carbon double bond, compounds that are based on the alkene skeleton, alkenes. What you are reading in the Gold book is the definition of the alkene skeleton - a hydrocarbon with one carbon-to-carbon double bond. Gold book goes on that cycloalkenes are also alkenes, but then with the extra addition that it also is a cyclic compound. The gold book defines the basic skeletons, and those definitions are used to extend in the other nomenclature definitions (if there is a chloride on the chain, it becomes a chloro..alkene etc. - still all alkene). And the world (school books, encyclopedia, peer reviewed articles) is using that as the definition of an alkene. But, again, I don't think we do that because the IUPAC tells us - IUPAC tells us to call a compound with a phosphorus a phosphane .. but the large majority of the world is still calling it a phosphine.
Oh, that one is fun. See http://goldbook.iupac.org/P04548.html. You see that phosphanes are compounds with the formula PnHn+2? But then it says that hydrocarbyl derivatives are called phosphines, which includes PH3 (hey, that was a phosphane). And then CH3PH2 .. is a substituted phosphane called methylphosphane. So it is a phosphane, while it is not PnHn+2. Just like DDE is an alkene, just not CnH2n. Alkenes are compounds based on the alkene skeleton, which makes DDE an alkene. And that goes perfectly well with the text of the lede of Alkene. --Dirk BeetstraTC04:58, 5 January 2014 (UTC)
In chemistry, an alkene is an organic compound containing at least one carbon–carbon double bond, and with other restrictions that vary from authority to authority. Similar terms are olefin and olefine. IUPAC recommends that the term "alkene" should be restricted to hydrocarbons with straight or branched structures, as opposed to cycloalkenes, aromatic compounds, and compounds with other elements or groups substituted for some or all of the hydrogen atoms. Most other authorities however commonly use the term "alkene" to include other compounds with similar structures and properties.
Something about IUPAC's gold book definition in the article is reasonable, but in the lede is UNDUE IMO.
Cycloalkenes are a sub-set of alkenes to everyone but IUPAC, aromatic compounds are not alkenes, this is a common misconception as students grapple with why benzene is not cyclohexatriene, despite the common representation.
The problem is that the term alkene can be used to mean the simple unbranched CnH2n homologous series, it can mean a compound with a C=C functional group, it can mean any hydrocarbon that includes an substituted C=C bond. The term does not have a single meaning and the connotation that goes with the term is context-dependent.
Alkenes in their broadest sense have similar structures depending on the meaning of "similar". Are ethylene and testosterone similar? Have they got similar properties?
"Other restrictions" from varying authorities? What restrictions are permissible? What authorities? If textbook authors differ slightly, are we to canvass views from a variety of sources. Are we basing restrictions on structural elements or functional chemistry?
Thanks for the feedback. I'd like to discuss several of these points further, and I think it would be more appropriate to do this at Talk:Alkene, as I said before, but if you prefer we could start a new section here. Your call. Andrewa (talk) 05:36, 5 January 2014 (UTC)
(replying to Andrew, do you want us to use... above...)
Good question! What a mouthful. My esters ended with alcohol + fatty acid (See [8] for some reminiscences which I thought better of).
I think it should be mentioned in the article, definitely. But I'm very skeptical that we should simply adopt this recommendation as the scope of the article, which is I think what you are asking. And I'm very interested in the views on this of others who know more chemistry than I do.
And this obviously has a bearing on the use(s) to which we put the term ester in the text of both this article and others. Not such a quick answer, sorry. Andrewa (talk) 05:30, 5 January 2014 (UTC)
Question, do you think that the IUPAC is 'dictating' the chemical world (that IUPAC is the authorative source), or do you think that the (chemical) world is 'dictating' IUPAC (is IUPAC trying to formalize how the chemical world is using terms, and that 'common use' is the source)? --Dirk BeetstraTC07:43, 5 January 2014 (UTC)
Good question and bad question both.
Good because what IUPAC should be doing is describing the current usage, and this point is lost on modern (cf postmodern) thinkers. Description has obsoleted prescription, and is the future of human thought. The only worthwhile future. It's actually been happening since the ancient Greeks at least, but we're getting better and better at it. So the answer is, (IUPAC is) trying to formalize how the chemical world is using terms, but note I've left off the second part, that's a far more involved question.
Bad because it doesn't really matter so far as Wikipedia is concerned. We are descriptive, and that is non-negotiable at many levels, and IUPAC recommendations are among the many things we describe. IUPAC is not the only source, but nor can it be ignored. In fact to even try to ignore it is probably to stoop back into prescriptive mode (=POV for most purposes).
To attempt as you have done to look through IUPAC and say essentially, do we agree with their methodology?, is also POV. We acknowledge them as worth reporting (I think... and if not we have a lot of rewriting to do, haven't we?), and report them. Whether they are right or wrong is not our job here to decide. That again would be POV.
And that is exactly what is in the lede of Alkene: it tells the definition of an alkene according to the IUPAC recommendation of '95, and about the 'simplest' alkene, ethylene. It does however not dismiss the other sources (which should be cited), which commonly call anything with a carbon-to-carbon double bond an alkene. So it is not a bad question - we are describing what IUPAC defines the base skeleton of an alkene. Actually, our definition is in agreement with the 'common use', and is not in conflict with the IUPAC (you did read the full legaleze in the recommendation, I presume). --Dirk BeetstraTC10:56, 5 January 2014 (UTC)
Andrewa: ".. IUPAC should be doing is describing the current usage.." Editors in this project have repeatedly demonstrated that textbooks and journal do not use IUPAC in the manner you think we/they should. And we resist being instructed to delude our readership into implying IUPAC has currency on this topic.
Andrewa: this statement strikes me a self-righteous "and this point (IUPAC's primacy) is lost on modern (cf postmodern) thinkers." reads "I'm going to teach those chemists a thing or two because I understand history and the way it should be because my very lack of qualifications qualifies me to instruct them. A bit harsh, but that's the way this discussion is going.--Smokefoot (talk) 13:57, 5 January 2014 (UTC)
I'm sorry that it strikes you as self-righteous, and I can see how it might. Part of the problem is that you (and others) have (again) completely misinterpreted what I said. You have added IUPAC's primacy as a clarification, but it is the complete opposite of what I said and what I have been saying consistently. IUPAC only ever had primacy because we had cited no other sources. See below.
Editors in this project have repeatedly demonstrated that textbooks and journal do not use IUPAC in the manner you think we/they should. I don't think that's quite fair, on two counts.
Editors did repeatedly state that this was so, and that's a start, but have only recently cited any sources (thank you), and I've taken that aboard. (And these references now belong in the article namespace.)
But more important, this again completely misunderstands my position. You (and others) seem to have jumped to the conclusion that, because I want the IUPAC recommendations to be acknowledged, I therefore want them to be slavishly followed, to the exclusion of all others. This has I think been an unhelpful position taken by others in the past, but it's not mine, and I've said this on many occasions, and frankly I'm getting a bit sick of saying it. Please, can you either say why you think I'm adopting this position, or stop accusing me of it?
I'm going to teach those chemists a thing or two because I understand history and the way it should be because my very lack of qualifications qualifies me to instruct them... ouch. There's a grain of truth in that, but it's not a fair summary at all. I'm not trying to teach anyone chemistry. I am fairly well qualified in Wikipedia policies and procedures. But there's another thing, probably most significant of all... We are a team. It's important for the WikiProject to listen to those without degrees in chemistry as well as those with them, because we represent an important part of the readership of these articles, and we can tell you how they read to the uninitiated.
@Andrewa: Part of the problem here is a weakness in wiki-policies. We can cite dozens of books that clearly use the term alkene in the way we chemists have stated, but pulling them together is vulnerable to OR or SYNTH claims. I pointed you to the Taber discussion of misconceptions that addresses the definitional problem somewhat, but I know of no source that explicitly says that IUPAC is ignored in some of its declarations. It reminds me of some pseudoscience debates, where a fringe claim is defended by its advocates as no scientific publication bothered to point out all of its fundamental flaws and so no scientific refutation is wiki-allowed in the article. I'm not suggesting you are advocating fringe, Andrew, let me hasten to add, but we are stuck between the same wiki-policy and a hard place. I could easily write a section for alkene on the how the term is used in different contexts with different connotations, citing different uses, but wiki-policy would allow me to be criticized for OR and SYNTH.
You have raised an important issue, though sadly it is being obscured (IMO) by the ongoing discussion... that is, that readers may be confused by the restrictiveness of the IUPAC reference and the wider use. Sadly, there is no simple wiki-compliant solution. Part of learning science is to develop an understanding of the common wisdom of the community of practice one is entering, and that includes nuances of terminology and overlapping meaning. Developing this often leads to confusion and uncertainty for a time (in line with the Perry Model in Chemistry, for example). As an academic, when teaching I try to help my students through this by explicitly discussing different meanings for some terms - equilibrium is a favourite of mine because we use it with a generic and specific connotation and students need to recognize which is meant - but I can't do it for every term. You can see the problem with the IUPAC definition of ester which is absurdly over-technical, in the alkene case it is the use of an overly-restricted meaning inconsistent with the more common uses.
The typical wiki-solution would be to state all the different approaches, consistent with their prominence, but a survey of slightly varying textbooks (for example) is not going to be helpful to readers. Also, from a chemist's perspective, the differences are trivial and nuances are obscuring the central topic. From a novice's perspective, presenting 5 differing meanings (especially in the lede) is confusing and what they want is a single approach - give three (say) and they want to know which is "true" and will struggle with the answer "all three are, in different circumstances". So, what do we do? EdChem (talk) 05:20, 6 January 2014 (UTC)
Wikipedia policies are not perfect. But if we ignore them, why have them? WP:IAR not withstanding... oh dear... (;-> it's a jungle out here. Agree that perfect wikipolicies would help... if I find any, I'll send them by the first pig that flies by.
What you can do... well, stop tolerating baseless personal attacks and other accusations against those trying to help you would be a good start.
Allowing standard stringing so detailed replies can be given to long essays like this would also help. My time is finite and valuable, like yours.
From a novice's perspective, presenting 5 differing meanings (especially in the lede) is confusing and what they want is a single approach... defeatest in my opinion. We call them as we see them fall, we don't oversimplify, but we do meet the general public where they are. And this takes teamwork. Do you want to participate in this? Or are you simply going to again accuse me of arrogance, or indulge in other timewasters? Andrewa (talk) 11:33, 6 January 2014 (UTC)
A valid objection, I don't think you have, and didn't intend the comment to apply to you personally. Others certainly have, and I'm sick of it. But I guess if I can't stand the heat... Andrewa (talk) 12:04, 6 January 2014 (UTC)
You didn't intend your comment to apply to me personally but included it in a paragraph that starts by quoting me? You are an admin, if you saw such a comment on a page you were looking at as an uninvolved admin, would you buy that excuse? I am not impressed. EdChem (talk) 12:48, 6 January 2014 (UTC)
Yes, I think I would. I admit that my phrasing, punctuation, whatever you like, is imperfect, and I have I think retracted the claims as you asked, but I do so explicitly now just for clarity. I note that you are unimpressed. I gained that impression some time ago, actually. Suggest we all lighten up a bit. Andrewa (talk) 15:12, 6 January 2014 (UTC)
Andrewa, in September, the article was citing a tertiary source for what is called an alkene in the common usage (there should be more, IMHO there should be a non-chemistry source there, can anyone dig it up in a proper regular encyclopedia - I only found the modern one in the current online Encyclopaedia Brittanica, which basically says 'an alkene is a chemical compound with a carbon-to-carbon double bond in it <pediod>'?), and it is citing the IUPAC nomenclature recommendation of '95 regarding how they classify alkenes. The text, as many people who read the IUPAC recommendations (<sigh> they are to be avoided), is not completely truthful to the recommendation, but the definition is acknowledged. So your remark that they 'only recently cited any sources' is wrong by any account. And 'I want the IUPAC recommendations to be acknowledged' then is similar, it was acknowledged, and it should be properly acknowledged (which I am not sure if it is in the revid I link), reading it completely and understanding what they are doing. --Dirk BeetstraTC05:16, 6 January 2014 (UTC)
I recognise that you don't like the IUPAC recommendations, and that this opinion carries some weight. I don't have an opinion either way; I have the definitions used in my high school science only, and finding them so obviously at odds with those used in Wikipedia I asked questions. Frankly, they were for a long time met with a response that can be summarised either trust us and get lost, or just get lost, and it's still wavering. My questions were no more welcome than that of the IP who innocently asked what is it? at Talk:Alkene. That's a great pity.
You shouldn't need a degree in chemistry to understand (and that means correctly interpret) the lede of the alkene article. Many people will come here wanting information who don't have any significant background in chemistry. It is a big challenge, and frankly, if you only listen to those either possessing or aiming for higher degrees in chemistry, you have very little chance of ever producing really good Wikipedia articles. (Good chemistry textbooks, yes.) You may satisfy the GA or even FA criteria, but that just shows that those criteria are not perfect either.
We could have a detailed article with a title like alkene (physical chemistry) with a more esoteric lede. I'm beginning to wonder whether that might be part of the answer (your thoughts?). But I haven't yet given up on an article that is equally useful to the beginner as to the professor. That's the best answer. Andrewa (talk) 11:33, 6 January 2014 (UTC)
WHAT? Who says that I don't like the IUPAC recommendations? I am getting really sick of your baseless accusations, utterly wrong interpretations, selective reading, ignoring other references, and your denigrating language. --Dirk BeetstraTC12:32, 6 January 2014 (UTC)
Andrewa:
Why do you accuse us of saying "trust us or get lost" - have we not pointed you to books stating that an alkene is a compound with a carbon-to-carbon double bond, recent sources and sources as old as 100 years. Accusing us of not referencing what is commonly regarded as an alkene and accusing us of ignoring the IUPAC recommendations.
Why do you interpret my remarks as not liking IUPAC recommendations
You obviously haven't read the whole of the IUPAC recommendation and what their writing of the definition of an alkene actually means
As said, you think that you plainly have to trust us, and you ignore when we show you references that say the same
So, even if we have GA or FA articles, we are still a bunch of nerds that are not able to explain what is explained everywhere else in the same way.
Fair enough if you wish to drop this. Several of my questions have already been quietly dropped. But just to substantiate these accusations:
The trust ua and get lost impression was gained when editors repeatedly referred to any chemistry book and similar non-citations. The citations were eventually forthcoming. They should have been there a lot earlier in the discussion.
I did not refer to you specifically, but several editors have been very denigrating of IUPAC recomendations... I can supply diffs and may in time, but it's hard to motivate myself to do so as when I have supplied diffs in the past they have just been ignored.
You obviously... An unsubstantiated generality. Exactly what provision of it am I ignoring?
I have ignored very little of what you have written, and have read it all. My questions on the other hand have frequently been quietly dropped unanswered.
I certainly haven't called you a bunch of nerds. I haven't even felt like it. I have repeatedly suggested that you need to listen to non-experts just the same as we need to listen to you, is that what you're rejecting here?
When my allegations have been challenged I have answered I hope. Whether you wish to do the same with these is of course entirely up to you.
I'm not yet convinced we are getting nowhere. There are some real issues, and I have not pursued them perfectly. And I don't win them all.
But it is certainly frustrating, on both sides. And you have the weight of numbers, regardless of the strength or otherwise of my arguments. Andrewa (talk) 14:54, 6 January 2014 (UTC)
There was a chemistry book referenced from the beginning, you even acknowledged from the start it was there.
Unless the you was opaquely plural, the "I recognise that you don't like the IUPAC recommendations ..." seemed pretty directly pointed at me. Otherwise, it is pointed at some other members, still it is unsubstantiated as well. We reference the IUPAC in the second sentence of the article, if we really did not like it it would be summarily ignored throughout. Especially since the second sentence is just an addition to the first, and the lede is perfectly correct without that sentence.
Well, from your answers it is clear that you did not read through the 1622 pages, and just read things under the header 'alkene' (and from the shortlist only showing that header, not even that whole page was absorbed, somehow I think you did not even open the 1622 pages). I am sorry, you clearly do not understand what you are looking at there, otherwise your argument would be different (I don't even think there is an argument then).
No, I know, but I do take the suggestion that we have very little chance of writing a good article.
Now, what part of "In organic chemistry, an alkene, olefin, or olefine is an unsaturatedchemical compound containing at least one carbon–carbon double bond." is not understandable .. it links to organic chemistry, chemical compound, carbon and double bond - so those term are explained there, and the whole sentence is referenced (and was so before this discussion started, so WP:AGF-ing on that the writer really verified that in the reference, that sentence is factual). Is it that sentence that is unclear, or is it just that you do not believe it because, according to your reading, IUPAC tells you different. If I read that sentence to the man in the street, do you think that they would understand (maybe after clarification of the terms organic chemistry, chemical compound, carbon and double bond)? Note, that is exactly what the IP was asking on the talkpage .. 'what is it?' - well, an alkene is a chemical compound containing at least one carbon-carbon double bond. --Dirk BeetstraTC16:10, 6 January 2014 (UTC)
I'm not sure whether to answer this in detail or not, but I certainly should take my time, as some of my responses have obviously been a bit hasty in glorious hindsight, and have at the very least been misunderstood. I'm hopeful that is much of the problem here.
And I still think that there is an issue with the alkene article. But how or even whether it's best to pursue it, I need to consider carefully. Andrewa (talk) 23:49, 6 January 2014 (UTC)
You keep insisting there is something wrong, and I was planning to cut the discussion short, but I decided to let it run (see where there are improvements possible, there are undoubtedly some - you entered the discussion and started to ask questions so some clarification may be at hand) - I hope that it is not belittling in the end. We've been led down a path of a logical fallacy (same glorious hindsight - and I think it is mostly a fault on our side for not stopping that at the root, and making the same 'mistake' that you made). One thing, I mistakenly was speaking about the intro of the 1622 page document, though our answers are there, it is not in that document, but as I argue in the next paragraph, we'll get there (for improvement sake).
Slow is fine, that is why I started off with the very, very first sentence, and stripped it down. Lets do it that way (maybe make yet another header for this?). Please, answer in detail on the first sentence, we'll get back to IUPAC later. --Dirk BeetstraTC05:28, 7 January 2014 (UTC)
First sentence of what exactly?
Yes, there is something that can and should be improved. Wrong is perhaps not the best way to think of it, it leads to needless confrontation. Andrewa (talk) 10:40, 7 January 2014 (UTC)
I think the intro is just fine, and does not need any improvement, but lets see where we get. What problem do you see with this sentence? --Dirk BeetstraTC10:59, 7 January 2014 (UTC)
I think the intro is just fine, and does not need any improvement, but lets see where we get. What problem do you see with this sentence?[9]
Let's have a look at the first sentence of my "proposal" [10] (noting I hope that despite some of what is said above I pointed out right at the start that it wasn't yet that).
In chemistry, an alkene is an organic compound containing at least one carbon–carbon double bond, and with other restrictions that vary from authority to authority.
(And we should note that this has already received some criticism [11] to which I have not replied.)
The main difference is the phrase with other restrictions that vary from authority to authority. It's been suggested this diff again that this is not the case, and that it's rather a case that The term does not have a single meaning and the connotation that goes with the term is context-dependent.
It still seems to me that authorities do vary significantly on what makes a compound an alkene. This may well depend on the topic area concerned, but it doesn't seem to be quite that simple. And again as this diff again says, it also depends on what we mean by authority. Is a high school text book, for example, also an authority? I certainly would not prefer it to a university level textbook (and please note that), but if another meaning turns out to be prevalent in high school texts, I think we need to inform readers of this early in the article. Perhaps even in the first sentence.
Just what sort of authorities we are citing should be clear from the citations themselves of course, and that is an important function of citations in Wikipedia.
The other main difference is that I said it was an organic compound rather than just a compound, and there was a consequential change earlier in the sentence. I thought this a useful point to make owing to what I perceive as a lack of clarity elsewhere. It seems to me that whatever differences there are in the scope of the terms alkene and even organic compound (and whether they arise from context or anything else), it's always the case that an alkene is an organic compound, and so it's useful to state this clearly. This is not a major difference in my opinion and I'm happy to let it go if there's any objection, but I still think it would add something however small to the article.
And there were also things I left out, intending to relegate them to later in the paragraph or article. And there's some extra wikification in the current version, and that's a good idea and should remain. Perhaps that's enough to discuss in one bite. Andrewa (talk) 05:49, 9 January 2014 (UTC)
And no, it does not have to be an organic compound (that one is restrictive in itself - some compounds are debatable organic, chemical compound is wider as there may be chemical compounds which are alkenes but which are debatable 'organic' (I don't have examples, but the limitation is in none of the definitions - if it is, show me). --Dirk BeetstraTC06:37, 9 January 2014 (UTC)
Diatomic carbon is formally C=C (at least in some of its major electronic states). And various Cn4– have been studied at least theoretically for calculating proton-affinities of ethene and cummulenes up to n=20. In all cases, the chemical and theoretical analyses appear consider them as if they were alkenes. DMacks (talk) 07:13, 9 January 2014 (UTC)
The organic compound page covers some of the debate on the organic / inorganic divide. Definitions mandating a C–H bond run into problems with cases like urea, cyanogen, carbon tetrachloride, Teflon, and oxalic acid in addition to several examples I noted above. The requirement for a carbon skeleton is similarly problematic for urea and all C1 compounds. Oxides of carbons begs a question about "simple" - which of these are "inorganic" simple oxides of carbon: CO, O=C=O, O=C=C=O, O=C=C=C=O, ..., CnO2, cyclopropanetrione (C3O3), cyclobutanetetrone (C4O4), etc, ethylenetetracarboxylic dianhydride (C6O6), and mellitic anhydride (C12O9)? A number of these examples is arguably inorganic but unarguably an alkene. I know I mentioned the situationally-dependent connotations of the term alkene - meaning the homologous series of terminal unbranched alkenes CnH2n, for example - but the broader definition is correct, I am now convinced. EdChem (talk) 07:28, 9 January 2014 (UTC)
CaCO3 is inorganic (we, 'organic' creatures eating organic food are built of it), urea is considered organic (no C-H, though the first synthesis of a 'organic' compound from an inorganic compound - disproving the vital force theory), buckyballs are organic (I doubt if there is an organic creature capable of making it). Lets keep it at chemical compound .. avoid that discussion/restriction as 'too specialised' for this lede - that discussion belongs somewhere else. --Dirk BeetstraTC07:50, 9 January 2014 (UTC)
Concur that debating inorganic / organic is not helpful for the alkene lede... illustrated in part by the fact I would say buckyball (C60) is an allotrope of an element and not a compound, organic or otherwise. :) EdChem (talk) 08:04, 9 January 2014 (UTC)
If you argue that buckyballs and graphite (and the related graphene) are allotropes of carbon and not a chemical compound (I think that S8 and C60 are distinct chemical compounds as well as an allotrope of the element, but well), then IUPAC even applies to .. how do we say .. chemical entities beyond chemical compounds .. not only to organics/inorganics/compounds. --Dirk BeetstraTC10:35, 9 January 2014 (UTC)
What I do think is that the link to 'unsaturated' is double to 'carbon-carbon double bond' - and we could discuss about 'carbon-carbon double bond', as compounds with a carbon-heteroatom double bond are heteroalkenes, analogues of alkenes (but the latter is certainly too detailed for the lede.
As the original lede was referenced, and you said above that it was unclear - besides your believe that different authorities have different definitions, do you think that that definition in the first sentence is unclear to a lay reader? --Dirk BeetstraTC07:01, 9 January 2014 (UTC)
Yes, it is unclear. And I'm happy to pursue this question (as indicated below), but I hope it will not be to the exclusion of the specific questions I have asked below. Andrewa (talk) 20:29, 9 January 2014 (UTC)
What is exactly unclear. Is it only unclear because you think that it conflicts with what you think is the IUPAC definition? --Dirk BeetstraTC20:49, 9 January 2014 (UTC)
No. If you check back you'll see that I didn't even know that the Gold Book existed, let alone that it was freely available online, when I started asking these questions (diffs available again if needed).
The problem is not IUPAC. But IUPAC does seem to me to be an obvious part of the solution, whether to support or to correct the obvious interpretation of it, either way. Even sitting on the fence and saying there are several interpretations is a good solution, if that's the case. But ignoring this IUPAC recommendation in the lede to the alkene article doesn't seem to have anything to recommend it, frankly.
And I recognise that this is revisiting old ground for you. I have innocently pressed something of a hot button. Point me to the previous discussion (as I did request previously, diff available if you like) and I'll try to avoid asking you to reinvent the wheel. Andrewa (talk) 23:38, 9 January 2014 (UTC)
Sigh, again, IUPAC has not been ignored in the lede for more than 5 years, it is there, referencing the second sentence (where we, for the sake of this discussion, did not get to).
Thanks for the replies. There's a lot of discussion there, much of it concerning what I described as not a major difference in my opinion. The example of urea is particularly relevant to the discussion, good point.
But I think we should focus on the major difference, which is also mentioned several times. I'm happy to reply to the specific questions above if others think it would be helpful, but see what you think of the direction below as well.
There are several requests above that I justify the claim that the precise scope of the term alkene varies from authority to authority. This seems obvious to me, and it's important in my opinion, so I'm anxious to pursue that.
I've expressed before the opinion that the Gold Book is a reliable source, and should be considered an authority. And frankly, we seem to go around in circles on this point, with one editor describing the alkene entry most negatively at one stage, and another who had not commented on this later replying angrily to me when I suggested that this same entry was not universally accepted (diffs available if anyone wishes to pursue this, but I suggest we let it drop at that and focus on the outstanding issue - is it authoritative, or not).
Let me try to preempt another well-travelled circle above. I said, and say again below, an authority, and I said a reliable source. I hope there will be no more misunderstanding there.
Several questions, and they all need answers in my opinion, except where a condition (such as if not or if so) is made. (And yes, that does include the last question.) The goal of course is consensus on each. The question I consider most important is first, the least important last.
Do you (wide use of the pronoun intended, not pinpointing any particular editor but rather inviting all interested to reply) accept that the IUPAC recommendation is an authority?
And if not, what sources would you accept? But if so, do you agree that the IUPAC recommendation on the term alkene does not include DDE within its scope?
And if so, do you agree that other authorities do include DDE within the scope of the term alkene? I'm a little surprised at even needing to ask this question, but it is important to clarify this point I think.
There is of course the question of context. I'm not yet sure whether or not this is a useful avenue of discussion, but it's been raised before and hasn't (yet) achieved circle status in my opinion. The context I intend in this discussion is that of the Wikipedia article Alkene. Does that need further clarification?
I'm happy to seek further references, but first I want to be sure that I'm not wasting my time finding ones that either aren't necessary or aren't relevant. Andrewa (talk) 20:16, 9 January 2014 (UTC)
Yes, I accept the IUPAC recommendation as a reliable source, and as an authority (though .. as it is a recommendation, it has its limits as to what it is a reliable source for, and, for some of the rules, one runs into curious exceptions). Widely put: it is a reliable source for the definitions it gives, and the rules it gives, it is not a reliable source for the names of compounds that one generates following the rules of the recommendations (with few exceptions where the names of compounds are given in the text) - generating those names is a form of WP:OR - and unfortunately, even articles in peer-reviewed journals are not a suitable reference either, as both the writers of the article, and the reviewers, probably use the same algorithm to resp. generate and 'check' the names, which quite obviously, will match. IUPAC is not 'validating' names (as far as I know). Databases (pubchem, ChemSpider) use the same (often computerised) algorithm to generate the names as well, or take them from the (peer reviewed) articles. --Dirk BeetstraTC20:34, 9 January 2014 (UTC)
Disagree that using the rules to generate names is in any sense WP:OR. This is a mechanical process, and there is nothing original about it. I think this is an important point.
You (specifically) appear be having a bet both ways on whether or not IUPAC is an authority. That puts me in a very difficult position.
But more important, doesn't this post strongly suggest that there are several different meanings of alkene (as a type of substance) in use in the professional literature? I can't see any other way to read it. So why are you (specifically) asking me for references to substantiate that point? Aren't you in a far better position to provide these? Andrewa (talk) 23:48, 9 January 2014 (UTC)
No, there is no instance validating your interpretation of the rules, so I believe that it is OR, synthesis - it is a primary source for the definitions/rules. And we have to be careful for what a reliable source is a reliable source - the question with reliable source is never "is this a reliable source", the question is "is this a reliable source for this information" (though I also tend to use the first way, it is technically wrong). Just to show, you say that DDE is not an alkene based on your interpretation of the rules. We say that DDE is an alkene as that is how all other sources call an alkene (and well, also IUPAC does, based on our interpretation of the rules).
No, not really. Currently I would say that only one definition is used in the chemical (and outside) world. The one expressed in the first sentence in the lede of Alkene is the one for compounds with a carbon-carbon double bond. Yes, I would be in a better position to find other references, if there would be references with other definitions that I am aware of. Remember, you are the one suggesting that the definition in the first sentence of Alkene is wrong depending on the authority - I don't think so, so I can't show you. --Dirk BeetstraTC05:42, 10 January 2014 (UTC)
Where our (the regulars in this WikiProject commenting here, so 'except you') logical failure is coming from is the knowledge that sometimes IUPAC rules give strange 'results'. That was expanded here to the apparent observation that many, well, practically all compounds with a carbon-carbon double bond are not alkenes/olefins. In fact, ONLY compounds of the formula CnH2n with one carbon-carbon double bond are, according to the wrong reading, alkenes. What all other compounds with a carbon-carbon double bond are is unknown, and it is utterly strange that for something this common, IUPAC rules do not agree in any form with what 'the chemical world', including tertiary sources like encyclopedia, all organic text books used in high schools, polytechnics, universities, etc., and all articles in journals with a (thorough) peer review system say (as I say above, there are known cases where the IUPAC rules give 'strange' results, but those are generally very esoteric cases).
You can try to find more references, but I am afraid that they will all suggest that a compound with a carbon-carbon double bond is, in fact, an alkene (per the IUPAC recommendation ..). --Dirk BeetstraTC20:34, 9 January 2014 (UTC)
But what is an acceptable reference? Would my high school chemistry books count for example if I find them? I suspect not.
Or are you (as one editor explicitly suggested a while ago, diff available if you wish) wishing to restrict the examples to undergraduate and higher level text books? Excluding not only high school text books (which is the context in which many if not most of our readers will first see the term alkene) but also articles in peer-reviewed journals? Andrewa (talk) 22:05, 9 January 2014 (UTC)
Oh anything, Andrewa - as I said, find more sources that talk about alkenes and which tell that compounds that do not follow the CnH2n-rule are not alkenes. I can not show them to you, as I don't think there really are (well, there are, there will be books that do not venture outside CnH2n for simplicity sake, and there may be some newspaper reports out there that did not venture outside of CnH2n either. Still, difficult to find). I suggest that you go to a library with chemistry book, and scan through them to see whether there are any cases of not-CnH2n that are nonetheless addressed as alkenes. A good handful of good encyclopedia, and see what they have to tell about some common non-CnH2n compounds with a carbon-carbon double bond, I bet they also will address them as alkenes. --Dirk BeetstraTC05:42, 10 January 2014 (UTC)
Sorry, but this is a really, really bad source: First of all, that document is heavily referenced to Wikipedia, which makes me question the reliability of it (if they base most of their info on a typically unreliable tertiary source .. though some info is based on proper sources!). Secondly, it is a document hosted on a wiki, which also makes me question the reliability of it by itself (being a wiki equals practically unreliability, unless reliably sourced). Thirdly, 'CnHn' is wrong, it is 'CnH2n' (suggesting that peer review has not taken place or it was insufficient), fourthly, and most importantly, you forget to mention the sentence before your quote: "If a double bond is formed in a hydrocarbon then the molecule is an alkene. An alkene has a chemical formula ...". I think that sentence is already flawed and in contrast with other sources, including IUPAC, but that is maybe to be expected and shows the unreliability of this source. You must surely be able to find sources published by respectable publishers. --Dirk BeetstraTC10:19, 10 January 2014 (UTC)
Agree, it's woeful... we know what they mean but, Oh dear! But Oh anything, Andrewa - as I said, find more sources that talk about alkenes and which tell that compounds that do not follow the CnH2n-rule are not alkenes (my amphasis) was the instruction, and it wan't terribly helpful frankly. (But the idea of the site is good... they just need some help.)
So I ask again, what sources do you consider relevant? I'm not surprised that you discount this one, and won't argue the point. But I do want to try to avoid surprises with sources that may represent a lot more work then being summarily dismissed. Andrewa (talk) 11:13, 10 January 2014 (UTC)
I already told that I think, respectable chemistry books, respectable encyclopedia, peer reviewed articles. But none of those sources will support the restricted and wrong view - they will say the same as what IUPAC says (or vice versa). --Dirk BeetstraTC11:49, 10 January 2014 (UTC)
I am actually unsure what you are asking - to find you a reference, a reliable source, that confirms your point? I don't know any, but if you can find one, I can tell you whether it is a reliable source or not. --Dirk BeetstraTC12:07, 10 January 2014 (UTC)
I am asking for guidance on the criteria you will use for making this call. This is an attempt to build consensus by the method of Plato's dialogues, and possibly as I said saving me a lot of time at the expense of a little of yours. Andrewa (talk) 20:40, 10 January 2014 (UTC)
Actually, the sentence "If a double bond is formed in a hydrocarbon then the molecule is an alkene" is not really wrong, however, it does not exclude that a non-hydrocarbon with a double bond is/can also (be) an alkene. --Dirk BeetstraTC10:35, 10 January 2014 (UTC)
Yes... but the intent here is definitely that DDE would not qualify, don't you think? The fact that the formula is W-R-O-N-G doesn't change that, that's a simple mistake, they meant CnH2n obviously. Andrewa (talk) 11:13, 10 January 2014 (UTC)
No, I don't think that it is definitely the intent here. This document is not a reliable source for the statement that DDE is not an alkene. --Dirk BeetstraTC11:49, 10 January 2014 (UTC)
But these are two separate issues: 1) whether the document is reliable, and 2} the meaning it gives to the term alkene. Do you really think it intends to include DDE? Andrewa (talk) 20:40, 10 January 2014 (UTC)
If the document is unreliable, then the definition it gives is unreliable and what the definition has within it's scope is then quite useless. What I think however, since you ask, is that it is not their intent to exclude others, their intent is to explain the basic concept in which they fail to include everything that actually is an alkene. --Dirk BeetstraTC07:28, 11 January 2014 (UTC)
You have by the way not answered to the question whether the statement, currently the first sentence of Alkene as referenced to Wade, is unclear in any form. --Dirk BeetstraTC20:37, 9 January 2014 (UTC)
Thinking about the source you offered, I wonder if the authors of it have also been influenced by IUPAC but not understood. Consider the simple compound CH2=CH-CH2-CH(OH)-CH3. That its name is pent-4-en-2-ol is uncontroversial, but how I would derive that would be by noting the 5 carbon chain ('pent-'), the PFG as OH (hence '-ol' and the numbering of the chain) and the carbon to carbon bonding dictating '-en-' at position 4. Look at how IUPAC does it with a "subtractive modification" changing an alkane chain to an alkene. However, they do not start from cyclic alkanes and subtract H in cases of aromaticexamples and so removing pairs of hydrogens to create C=C bonds does not necessarily mean turning an alkane into an alkene. Just some thoughts... EdChem (talk) 13:23, 11 January 2014 (UTC)
Whether these particular authors have or have not been influenced by the Gold Book at their level of understanding, I expect others have and will. That is part of the reason that I think we need to give a bit more prominence to the IUPAC recommendations, whether we choose to follow them at this level or not. Andrewa (talk) 23:10, 12 January 2014 (UTC)
This is agreed to be an important point by the two subsequent posts in the string, and the same point is made several times in other places, so I think it would be useful to focus on it in a dedicated section. Andrewa (talk) 21:17, 10 January 2014 (UTC)
Sorry, missed these additions this morning (and probably even yesterday evening).
I agree, though it is closely related and the crux of the rest of the discussion. Note, this is not about interpretation of the Gold Book, this is about reading and understanding the Gold Book. --Dirk BeetstraTC13:34, 11 January 2014 (UTC)
Thank you for the clarification. Interpretation was your term of course.
And it seems important, not just because you bring it up (which would be reason enough) but because I have absolutely no idea what the distinction is between interpretation and reading and understanding in this context. Andrewa (talk) 19:35, 11 January 2014 (UTC)
You've got me there to a certain extend. Note though that I am talking about interpretation of the rules, not about interpretation of the Gold Book.
what is the difference? I think that before one interprets the rules, one should read and understand what the rules are about. That right interpretation then shows then that 'the authorities' all say basically the same as what the first sentence of alkene says: chemical compounds, including DDE, with a carbon-carbon double bond are alkenes. --Dirk BeetstraTC20:14, 11 January 2014 (UTC)
Certainly there is no argument that before one interprets the rules, one should read and understand what the rules are about.
But I question the jump from this to the right interpretation as you see it. This may well be meaning of alkene we end up with, I'm not questioning that for now. But I am questioning the route taken. The Gold Book does not, of itself, support this meaning in any way that I can yet see. You provided links to two PDFs a while ago, which I'm looking at as you suggested. Can you suggest any particular passages or pages within these PDFs that support this reading? Andrewa (talk) 23:45, 12 January 2014 (UTC)
Well, if our interpretation can differ then all our conclusions would be original research - There should be, after reading the rules, no question that something is what they mean, which then automatically would be the right interpretation.
I may get back to the discussion above, although it seems to be going in the same circles... whether that's my fault or not is probably itself open to interpretation.
But another important aspect of the interpretation of the IUPAC rules (recommendations if you like, as presented in the Gold Book) has been raised several times now... does applying them constitute WP:OR, and are they a reliable secondary source?
The relevant policies are of course Wikipedia:No original research and Wikipedia:Verifiability. In fact, on closer inspection it's just the first of these. Perhaps this is a surprise, but Wikipedia:Verifiability currently [12] refers to primary, secondary and tertiary topics sources corrected - read sources not topics, don't know what my fingers were thinking Andrewa (talk) 04:28, 13 January 2014 (UTC)only where it refers to Wikipedia:No original research. (And note also that Wikipedia:Reliable secondary source simply redirects to Wikipedia:Verifiability.)
So we are left with WP:OR. I think it's a stretch to say that this discriminates, or intends to discriminate, against the Gold Book. It says little about tertiary sources, mostly it talks about reliable sources in general, or contrasts primary to secondary sources. And there are restrictions and cautions on the use of primary sources, and on the use of Wikipedia itself as a source (an almost complete ban, in the case of Wikipedia).
But there is nothing that I can see that would or should discourage the use or citing of the Gold Book on the question of whether or not DDE is an alkene, or on similar questions that represent mechanical application of the rules and/or recommendations (mechanical as in, is CCL4 of the form CnH2n+2 - yes I know that's not about alkenes, it's a different example). Please note, I'm not saying it's the only source that can or should be cited. I'm simply saying that to do so is not WP:OR. Andrewa (talk) 22:36, 12 January 2014 (UTC)
I am at a loss here why it would discriminate against a source. What I am saying is that the Gold Book is directly supporting that chemical compounds with a carbon-carbon double bond are alkenes (that does not involve synthesis, it is what IUPAC says), but the Gold Book is not directly supporting that the compound on the right is named Methyl (1S,4R,5R)-8-methyl-3-oxo-8-azabicyclo[3.2.1]octane-4-carboxylate - that involves combining rules, and selecting what is the framework of the compound, and what is deemed the most important chemical group, considering where one needs to start counting and following that. "Articles may not contain any new analysis or synthesis of published material that serves to advance a position not clearly advanced by the sources themselves." It is not clearly advancing the name for Carbomethoxytropinone, it is clearly advancing that compounds with a carbon-carbon double bond are alkenes, as does it clearly advance that carbomethoxytropinone is an ester, an amine, and a ketone (even though the synthesised name is not making that clear). --Dirk BeetstraTC04:23, 13 January 2014 (UTC)
The claim that the Gold Book is directly supporting that chemical compounds with a carbon-carbon double bond are alkenes is key here. It's a bit vague. I'd agree that the Gold Book supports the claim that somechemical compounds with a carbon-carbon double bond are alkenes, but you seem to be claiming something more than this.
The 1670 page document goldbook.pdf entitled International Union of Pure and Applied Chemistry Compendium of Chemical Terminology Gold Book Version 2.3.2 2012-08-19 IUPAC Compendium of Chemical Terminology and to which you linked earlier contains the term alkene in 47 places. I have now looked at all of them, and not one of these occurrences seems to substantiate your claim.
If you think I'm wrong in this, could you indicate just one of them that appears to you to do so? The best example, preferably. Andrewa (talk) 10:39, 13 January 2014 (UTC)
If it is vague, then it is IUPAC that is vague (and I do agree to that). I still don't see why my statement, or what Wikipedia says about it, is vague. Note, you are here reading a 'compendium', a comprehensive compilation of a body of knowledge (and that with already 1670 pages). As I say above, the 'definition of an alkene' is sourced to the original publication (which is the same source as has been in the lede of the article Alkene for over 5 years). As I said, I first also read it wrong (that is the vagueness of IUPAC I guess), what I want to get at is how we can improve the lede so that it becomes more clear (to me, now I see it, it is clear, but what I hope to understand is where your confusion originates). I think that it is due to IUPAC itself, and maybe we need to address that in the footnote/reference to the IUPAC document (which would need to be copied to all the pages about 'functional groups', which seems excessive), or maybe elsewhere (which may be better, but where). --Dirk BeetstraTC12:31, 13 January 2014 (UTC)
You could try and see what, based on IUPAC rules, is the systematic name of the compound on the right. And do you agree that the compound is, according to IUPAC, a ketone, an amine, a bicyclic compound, and an ester? --Dirk BeetstraTC05:44, 13 January 2014 (UTC)
I'm happy to take your word for it that the compound is, according to IUPAC, a ketone, an amine, a bicyclic compound, and an ester. But I don't see what the relevance is of this. Andrewa (talk) 10:39, 13 January 2014 (UTC)
You don't agree that DDE is an alkene, and now you take my word on this. I want you to understand that the reading of the definition confirms that DDE is an alkene, and that this is a ketone, an amine, a bicyclic compound and an ester (or say the opposite again, which may help us further as well). I am trying very hard here to understand where the confusion stems from (that is why I may seem not too forthcoming, though I get more and more convinced taht it is IUPAC itself that is too 'specialistic' (vague, confusing) in its writing, so maybe that is what needs addressing). --Dirk BeetstraTC12:31, 13 January 2014 (UTC)
Whether or not I think that DDE is an alkene is not terribly important. The issue is, what do the IUPAC recommendations suggest? You have said that they suggest that DDE is an alkene. Where? It doesn't seem to be a possible reading of any of the mentions of the word alkene in the document in question. Andrewa (talk) 13:26, 13 January 2014 (UTC)
That is why I ask, what do the IUPAC recommendations suggest for an amine, ketone and an ester, and how do they apply to the compound discussed here. Do you run into the same confusion? --Dirk BeetstraTC13:42, 13 January 2014 (UTC)
No. Having looked at our articles amine, ketone, ester, and at the Gold Book as you suggest, there's no obvious problem to me. The compound seems, to my naive eyes, to be an example of all three, and there's nothing to suggest that it would not be. What do you see that suggests otherwise?
And you still haven't tried to answer my question as to why you think the Gold Book is directly supporting that chemical compounds with a carbon-carbon double bond are alkenes (my emphasis). You said above you don't think this is vague, but do you mean all chemical compounds with a carbon-carbon double bond, or some chemical compounds with a carbon-carbon double bond, or something else? I think that ambiguity may be the problem here. Andrewa (talk) 19:26, 14 January 2014 (UTC)
"Compounds formally derived from ammonia by replacing one, two or three hydrogen atoms by hydrocarbyl groups ..." (from http://goldbook.iupac.org/A00274.html) .. But according to your reading, these are not hydrocarbyl (http://goldbook.iupac.org/H02891.html -"Univalent groups formed by removing a hydrogen atom from a hydrocarbon...", and hydrocarbon: http://goldbook.iupac.org/H02889.html "Compounds consisting of carbon and hydrogen only.", they contain oxygen somewhere in the hydrocarbyl group, just like DDE has chlorines and fluorines as substituents on the two doubly bonded carbons.
I mean all compounds with a carbon-carbon double bond, as does IUPAC. As is the discussed compound an amine, even if there are oxygens in the hydrocarbyl.
This simply confirms that the confusion is not with Wikipedia's writing. Do you think that IUPAC writes ambiguous rules? Do you understand what you are reading the definition of? The compendium is referring back to a glossary of definitions. Definitions of what? your mindset has always been that Wikipedia was conflicting with IUPAC. Some have told you it is not, I asked you what was confusing in the first sentence, but from what I gather the only confusion you have is that you think that our lede is in conflict with IUPAC, nothing more. So it is not our lede. The question now is, do we have to spell out in all 'our' articles why 'our' definition is the same as IUPAC, or are we doing fine - I think we are doing fine. --Dirk BeetstraTC20:10, 14 January 2014 (UTC)
I think we are doing fine because we correctly attribute what we are saying to IUPAC, spelling it out more in the lede of each article is, as was suggested earlier, giving undue weight to IUPAC in the lede. --Dirk BeetstraTC20:45, 14 January 2014 (UTC)
You say you looked at amine, which bluntly states that an amine is a compound where 1, 2, or 3 protons have been replaced by an alkyl, and then poses that an aminoacid is an example. None of the amino acids have the amino part substituted with only alkyls. So if your reading is right, also 'our' article on amines is wrong. --Dirk BeetstraTC20:20, 14 January 2014 (UTC)
Good point. The lede of the amine article does need work. Its first sentence currently reads [13]Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Later in that paragraph however it says Inorganic derivatives of ammonia are also called amines.... We can't have it both ways, surely? The lede should either start In organic chemistry... to scope the article to this narrower context (if the organic compounds are the primary topic, which seems unlikely), or (more likely) scope the article to include inorganic compounds.
So your underlying point is that many more articles might be affected if my contention that the IUPAC recommendation should be referred to prominently in the lede of the alkene article were to be accepted? I have long suspected this to be the case. This was exactly my point (4) ages ago, which was at the time dismissed.
Oh for goodness sake. Can you please drop your dogmatic thinking that Wikipedia is wrong and is not following IUPAC. Can we finally start understanding that the problem is that you do not understand what IUPAC is doing. What we write about alkene is exactly within IUPAC's definitions, as is the definition of amine (I do however agree, that the first sentence should read 'Amines are chemical compounds.' - they need, for no reason, be strictly organic. --Dirk BeetstraTC03:23, 15 January 2014 (UTC)
(bit of a side-track, but to illustrate the point of where following the rules from the Gold Book gives 'curious' results - following the rules says one, even though it complies with another rule but that rule is 'not followed' for this purpose)
The compound on the right is 2-Carbomethoxytropinone, and following the IUPAC rules gives as a systematic name 'Methyl (1S,4R,5R)-8-methyl-3-oxo-8-azabicyclo[3.2.1]octane-4-carboxylate'. Note that the name of the compound does not suggest that it is an amine ("Compounds formally derived from ammonia by replacing one, two or three hydrogen atoms by hydrocarbyl groups, and having the general structures RNH2 (primary amines), R2NH (secondary amines), R3N (tertiary amines)."; per PAC, 1995, 67, 1307 (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1316) - unlike dichlorodifluoroethylene (which does). Obviously, there is an amine in there, the nitrogen with the three substituents, and I am confident that all organic chemists will agree with you if you call this a tertiary amine - even IUPAC. However, according to IUPAC, this is an azabicycloalkane. (Note that 'it is also not a ketone' ..). --Dirk BeetstraTC14:17, 11 January 2014 (UTC)
Not a ketone? PAC, 1995, 67, 1307 (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1346) says a ketone is a compound "in which a carbonyl group is bonded to two carbon atoms R2C=O (neither R may be H)," a definition which this compound satisfies. It is not named as a ketone, but it is a ketone. EdChem (talk) 14:36, 11 January 2014 (UTC)
Fascinating compound, and such diversions are useful in educating me... which according to some theories is the whole solution to some of the discussions above.
A query... the related article (a set index) at C10H15NO3 says exact mass : 197.105193, but is this true of all four compounds listed? That's what the article appears to say currently.
And another, which may show my extreme naivity... surely such curiosities are inevitable in any attempt at classification and/or taxonomy? Is the example above any stranger than the (far less exotic) (re)naming of isopentane as methylbutane? Yes, some of its properties are closer to butane than to pentane, but not all of them.
A decision needed to be made, and some things were left out. The alternative, taken to its logical conclusion, would be to have the entire text of the ultimate Wikipedia article on the topic as the systematic name... obviously not a practical outcome, even in this information age.
Another perhaps naive question... surely the name 2-methylbutane (currently in the infobox) is overly precise, even for IUPAC? Is that really the systematic name according to their recommendations? If so, that's an obvious if minor tweak that should be recommended to them, in my opinion.
I am not sure if educating is the solution, I am trying to learn from you where confusion lies. Don't seem to effective in it though - I don't seem to get the unclarity really, except for maybe that the IUPAC is unclear in itself.
Any compound with the formula C10H15NO3 has as exact mass 197.105193, yes (ignoring the (anyway infinitesimal small) differences in relativistic effects, they have the EXACT same exact mass (mass for the main isotope of C is exactly defined, as for H, for N and for O, and multiplying them with the number of each atom gives always the same exact weight (and molecular weight as well). The differences in connectivity may give differences in other properties though - methylbutane has the same molecular and exact weight as pentane, but different density.
It's the relativistic effects I was wondering about... but if what you say is true, then even nine significant figures doesn't get us into that ballpark. Fair enough. Andrewa (talk) 17:17, 12 January 2014 (UTC)
I presume that that would at some point limit the precision, and that means that you stop there (or earlier if other experimental errors are bigger). If those numbers are as precise as they can be, then this is the best precision we can give. Nu clue what the current limit of precision is, or why. --Dirk BeetstraTC17:48, 12 January 2014 (UTC)
limit the precision... no, at the nuclear level, these relativistic effects (such as binding energy I assume you mean) are very significant. Similar effects will be seen at a molecular level, and I don't know how many orders of magnitude down these effects are, so when you tell me it's far greater than nine (as your comment infinitesimal small indicates) then I'll believe you. That's what I was wondering, really. Andrewa (talk) 23:00, 12 January 2014 (UTC)
Other taxonomies likely also have that type of effects. For the compound example above the taxonomy goes through a certain path of rules, resulting in a name - that 'path'/algorithm does not go through the 'amine' and 'ketone' rules as higher rules take over. Does not mean that the compound is not an amine (it has a nitrogen with three (hydrogen or hydrocarbyl) groups - yes .. hydrocarbyl .. !!!) or a ketone (carbon with a doubly bonded oxygen with on both sides of the carbon another carbon) though.
Yes, I would call the curiosity of the systematic name for 2-carbomethoxytropinone different than the methylbutane/isopentane curiosity. Isopentane is a commonly used name for methylbutane (not sure if it is 'IUPAC allowed', I think they retain the 'iso<something>' naming as non-systematic (have to check)). Methylbutane is the systematic name (which does full respect to what it is, an alkane) - I chose the compound 2-carbomethoxytropinone because the systematic name of the compound not clearly reflcts that it is an amine (see triethylamine, from the name we would immediately agree that it is likely an amine) or a ketone (see acetone, the 'one' clearly suggests it is a ketone).
Heh, that is funny. Indeed, I think the '2-' could be left out if you follow the IUPAC rules. Appears useless to me, it can not be anywhere else than on the 'second carbon' (the first carbon would make the chain longer, the third and fourth carbon are 'reading' the compound from the wrong side). Funny, is this a misinterpretation of the IUPAC rules that resulted in that name, or is IUPAC here missing something? --Dirk BeetstraTC16:41, 12 January 2014 (UTC)
Exactly. My opinion is that the infobox in our article on isopentane is quite simply wrong. But this then suggests that the source cited [14] is also wrong, or at least misleading.
So let's check that source: Also known as: 2-Methylbutane, ISOPENTANE, Butane, 2-methyl-, Isoamylhydride, iso-Pentane, 78-78-4, Dimethylethylmethane, Ethyldimethylmethane, Butanes. There's no mention of methylbutane unqualified, even with the list expanded [15]. But does this site claim that this is a complete list, or even that it includes the IUPAC name at all? Not by my reading of it. So on closer inspection, the source does not in any way support the claim made. Frankly, it looks like pure carelessness. Whoever last either added the 2 or the citation (I can't be bothered checking this) simply didn't check that the source supported our text. And it doesn't.
This should be a very simple application of the IUPAC rules, and I was seeking an opinion from those more familiar with them. Now that I have one, would it be overly bold of me to change the article? Andrewa (talk) 17:17, 12 January 2014 (UTC)
Hah .. diff. Thát is where that came from. It even carries a 'reference' to a database that does not say that '2-methylbutane' is the systematic name (I don't think that a database is a reliable source for that), it is listed in the 'also known as'-list and in the 'depositor-supplied synonyms'. Good catch, Andrewa. Now I wonder if a reliable source can be found that that compound's systematic name is '2-methylbutane' or 'methylbutane', or that we can only get that by following the IUPAC rules? --Dirk BeetstraTC16:49, 12 January 2014 (UTC)
Based upon my interpretation of the IUPAC rules (which, I still insist, is original research), I think that the systematic name should be simply 'methylbutane', though 2-methylbutane seems to be a commonly used 'other name' for the compound, probably worth mentioning. --Dirk BeetstraTC16:55, 12 January 2014 (UTC)
This somehow crossed my post above. The question of whether following the IUPAC rules is WP:OR is to me a no-brainer, there's nothing remotely original about it, but perhaps we need to follow this up. Andrewa (talk) 17:21, 12 January 2014 (UTC)
A no-brainer ... You are generating something by interpreting what an article describes. And that resulted in Plasmic Physics add 2-methyl butane as the systematic name, and your interpretation that DDE is not an Alkene according to those IUPAC rules. IUPAC is not saying that DDE is an Alkene, but if you interpret their rules you conclude it is an Alkene. IUPAC is not saying that the compound is methyl butane (actually, maybe it is in their examples ...), If you follow their rules you conclude it is the name. --Dirk BeetstraTC17:31, 12 January 2014 (UTC)
Oh, there's no doubt that one can make an error in following the rules or recommendations, or in referencing a database, and I think this is probably the problem with methylbutane and/or methylpropane. This doesn't make it WP:OR, any more than the possibility of typos makes all contributions WP:OR. But how you can conclude that it follows from the Gold Book recommendations that DDE is an alkene still eludes me. Andrewa (talk) 00:38, 13 January 2014 (UTC)
Not a valid inference, assuming that by directly supported you mean supported without resorting to what Wikipedia regards as original research, which is the issue. The policy gives absolutely no justification for this extreme reading of the phrase original research. Not sure how to resolve this. Andrewa (talk) 23:03, 14 January 2014 (UTC)
Does the Gold Book tell you that the compound is called 'Methyl (1S,4R,5R)-8-methyl-3-oxo-8-azabicyclo[3.2.1]octane-4-carboxylate' (did you search for that name, can you show me the page where IUPAC tells you that is the name)? No, it does not, it gives you rules that let you derive that that is what they deem to be the systematic name. I can't see how that is directly supported. Also, for methylbutane, you say that it is wrong in your opinion, you should be able to say 'no, it is wrong because look, I have this WP:RS that is disputing it'. No, all you have is a self published source (albeit from a respectable organisation) containing definitions. --Dirk BeetstraTC03:40, 15 January 2014 (UTC)
In fact, I can question the name 'methylbutane' with "but respectable databases like pubchem are, amongst others, using the name '2-methylbutane', are you sure you correctly interpreted the IUPAC rules?". --Dirk BeetstraTC04:29, 13 January 2014 (UTC)
Not at all. I haven't even looked at them on this particular issue... and if I claimed to have done so, that was in error. Andrewa (talk) 06:24, 13 January 2014 (UTC)
Grr (the word 'you' is always a source of misinterpretation in discussions) .. sorry, this was a generic 'you', not aimed at you (Andrewa) personally. You did not claim so. --Dirk BeetstraTC06:33, 13 January 2014 (UTC)
The confusion here, I think, is that the IUPAC definition is describing what compounds fit in the category of alkene ONLY, hence it says it must contain C and H only. If you substitute any other elements etc then it also becomes something else (if the substituent is a halide then an alkyl or vinyl halide etc). But if it still contains a C=C double bond and is not aromatic then it still is an alkene but also something else as well. 122.109.114.21 (talk) 13:32, 13 January 2014 (UTC)
Yes. But where is that confusion here on Wikipedia now coming from - why does that not get read in the IUPAC documents? The lede of Alkene is pointing you in the right direction, still it, apparently, gives this confusion. --Dirk BeetstraTC13:48, 13 January 2014 (UTC)
Well, no actually - it is a bit more complicated than that, but you are thinking in the right direction. Still, do we have to make that more clear, or is it good enough (if you read it properly, it is correct, and hence, Wikipedia's information is properly attributed, even if it is unclear to some). --Dirk BeetstraTC13:49, 13 January 2014 (UTC)
Motivations
A few (in)organikers have already weighed in on their views what an alkene is. This group calls anything with a carbon-carbon double bond an alkene, because that functionality does such things as electrophilic addition, oxidative addition, it forms pi-complexes, you can add radicals across the double bond &c. An unsurprising outcome, considering that chemists today are interested in structure-reactivity relations, chemists want to build things, they are not stamp collectors.
If petroleum engineers had written the article the outcome might well have been different, to those guys alkenes are what comes out of your cracking unit. They would call the unsaturated stream the alkene stream, and this includes the cyclic alkenes.
(-: - actually, what 'petroleum engineers' call alkenes (I wonder what I, with an organic chemistry schooling, organometallic chemistry PhD and now working for a petrochemical company am) very well fits with what (in)organikers call an alkene, isn't it. I mean, the unsaturated stream that comes out of our crackers, the alkene stream, is just that: compounds, mainly C,H-based, with 1, 2 or more carbon-to-carbon double bonds, some linear, some cyclic (some aromatic, which one could question being an alkene), and a bit with some heteroatoms in it. Exactly what I, with my organic hat on, would call a mixture of alkene. --Dirk BeetstraTC18:32, 5 January 2014 (UTC)
Oh, by the way, we don't call it an alkene because it does the things you describe, we call it an alkene because of the chemical structure, and because of the chemical structure, it (typically) does the things you describe (you forgot 'polymerise'). --Dirk BeetstraTC18:34, 5 January 2014 (UTC)
