Template talk:List of oxidation states of the elements/Archive 1

Comment
use this link Nergaal (talk) 19:18, 25 December 2007 (UTC)

Disagreement with CRC Press
There are many differences from the CRC press periodic table's list of oxidation states http://www.chemnetbase.com/periodic_table/01_17_86.pdf. Are they listing common or all? How did we select which to label common? —Preceding unsigned comment added by Lucent (talk • contribs) 04:29, 22 December 2008 (UTC)


 * They are only listing the more usual oxidation states. Our list is based on Greenwood & Earnshaw (see the ref. at the bottom), which is much more comprehensive, with only a few extra oxidation states added (each addition is clearly labeled and referenced). The oxidation states that are labeled here as "common" are the ones labeled as common by G&E. I think it is safe to bet that no new "common" oxidation states will be discovered--all new discoveries are pretty exotic. --Itub (talk) 15:05, 22 December 2008 (UTC)

Astatine +7
Are we sure about this?

http://books.google.com/books?id=UPBKxgY20lEC&pg=PA220&lpg=PA220#v=onepage

This indicates that AtO4- doesn't exist, and because of the inert pair effect and lack of references, AtF7 seems unlikely. —Preceding unsigned comment added by Kazyan1 (talk • contribs) 05:32, 9 May 2010 (UTC)
 * actually exists; however, not many books mention it, for reasons discussed at Talk:Astatine. isn't known yet AFAIK. Double sharp (talk) 10:12, 16 June 2012 (UTC)

Fractional oxidation states
We need a good way to show these. E.g. for O, we have, just listing the obvious ones: −½ (superoxides), −⅓ (ozonides), +½ (dioxygenyl). Doubtless C has a lot more, as another example. Double sharp (talk) 12:07, 13 October 2013 (UTC)

Thulium(IV) - probably incorrect
The reference quoted for this pradyot patnaik's handbook of inorganic chemicals- yes he does say that +4 compounds are known (unreferenced) - but he is alone in this as far as I can tell. For example a recent review of Ln(IV) compounds in the Encyclopedia of Inorganic and Bioinorganic Chemistry DOI: 10.1002/9781119951438.eibc2033 does not mention Tm(IV) at all. To include this we need a reliable corroborative referenceAxiosaurus (talk) 10:50, 22 March 2014 (UTC)
 * I've removed it here, pending reliable corroborative references. I see the Tm(IV) claim is already marked as "dubious" in Thulium. Double sharp (talk) 14:21, 22 April 2014 (UTC)
 * Tm(IV) was claimed in 1982 in Cs3TmF7 (see ). This article (in Russian; English abstract) also mentions Sm(IV), Fe(VII), Fe(VIII), Ag(V), Co(VI), and Cf(V); however, Fe(VII), Fe(VIII), and Ag(V) have subsequently been refuted, Cf(V) seems to be controversial, and I don't know much about Co(VI) or Sm(IV).Burzuchius (talk) 20:44, 8 March 2015 (UTC)

Oxidation states −5 and −6
I have found a Russian blog listing some examples of oxidation states −5 and −6: BeAlB, Al3BC, Mg5Ga2, Mg5In2, Mg5Tl2, LiMg2Ga; Ca3Zn, Mg3Hg, Ca3Hg, Sr3Hg, Ba3Hg. In other sites, I have found confirmations only for Al3BC (, p. 139) and Mg5Ga2 (, I have already mentioned it). Burzuchius (talk) 19:09, 10 March 2015 (UTC)


 * The ion Tl5− has been reported in . However, another ion mentioned in that article, Tl37−, seems to have been disputed in .Burzuchius (talk) 11:45, 11 March 2015 (UTC)


 * , p. 15 and, p. 5 state that LiMg2Tl is a Zintl phase. If it is so, than the oxidation state of thallium in this compound should be −5.Burzuchius (talk) 11:51, 13 March 2015 (UTC)


 * A new column, at last! I've been wondering about the negative side for a while! (Unfortunately that will also make it a bit of a pain to insert, but we'll get to it!) Double sharp (talk) 01:11, 14 March 2015 (UTC)


 * I have added −5. I am not completely sure about the compound of thallium, which is so unusual and non-stoichiometric. Mg5Tl2 and LiMg2Tl have much simpler chemical formulas, but unfortunately I have not found any authoritative source that explicitly stated they have Tl(−5). Burzuchius (talk) 18:24, 3 April 2015 (UTC)


 * According to, LiMg2Tl and Sr5Tl3H do contain Tl(−5).Burzuchius (talk) 21:50, 10 May 2015 (UTC)

Accessibility
The color-coding of elements and noble gases is not in compliance with WP:ACCESSIBILITY. We need a way to indicate that information without having to rely on color.--Jasper Deng (talk) 03:15, 21 July 2015 (UTC)

Some questions
Here are some cases where I am in doubt.

Boron. There are borides, so there should be negative oxidation states of boron. In the history of the article, B(−1) was once added and then deleted. There is MgB2, and if it has B(−1), it satisfies the Zintl–Klemm rule, since the atoms of boron form the structure of graphite and graphite is a form of carbon. However, AlB2 also has this structure, so it has Al(+2)? Or is it an electride?


 * MgB2, according to, p. 183; , p. 315; and , can indeed be considered a Zintl-like compound containing B(−1). (However, I am under impression that all conducting compounds except ionic liquids may be regarded as electrides; in this case, metallic Na is Na+e−, graphite is C+e− (three electrons go for covalent bonds, one for conductivity), and MgB2 is Mg2+B02•2e−.) I think that boron has −3 in CrB in FeB, since boron atoms in these compounds form sulfur-like chains, but I haven't find any source stating so. For −5, see below. Boron can also have fractional oxidation states, e.g. in CaB6 (LaB6 has a similar structure, so it may be regarded as an electride, see ). Burzuchius (talk) 11:51, 13 March 2015 (UTC)


 * Now I think that regarding graphite as an electride is not a good idea and MgB2 is a valid example of boron(−1). Added MgB2. AlB2 is perhaps something electride-like. Burzuchius (talk) 16:39, 21 May 2015 (UTC)

Chlorine(+2, +6). Greenwood&Earnshaw mention them in the table, but in what compounds do they occur? ClO⋅ and Cl2O2 have Cl(+1) and O(−1). For Cl(+6), a widely cited example is Cl2O6, but according to the Wikipedia article Dichlorine hexoxide, it is actually a chlorine(V,VII) oxide, and ClO3 is an error.
 * Good question, and I don't know the answer; but judging from the title, this article mighr help. Double sharp (talk) 14:30, 1 March 2015 (UTC)
 * ClO3 actually exists. Added a note.Burzuchius (talk) 15:56, 25 March 2015 (UTC)
 * For Cl(II), there is an article about ClF2: .Burzuchius (talk) 21:23, 25 March 2015 (UTC)
 * Some information about ClO, BrO, and IO:, , , , . I am in doubt whether the oxidation states in these radicals should be considered +2 and −2 or +1 and −1. Burzuchius (talk) 13:45, 31 July 2015 (UTC)

Tellurium(+5). Again, Greenwood&Earnshaw mention it in the table. But they do not mention any compounds of Te(V). Ditellurium decafluoride (Te2F10) is an error. However, I have found an article called [http://pubs.acs.org/doi/abs/10.1021/jp010577i Tellurium(V). A Pulse Radiolysis Study] and also similar articles about arsenic(IV) and selenium(V). Are they valid?
 * I think they're valid. Added As(IV) and Se(V), as well as an explanatory note for Te(V). Double sharp (talk) 13:38, 3 March 2015 (UTC)

Xenon(+1). The formula Xe+[PtF6]− for xenon hexafluoroplatinate is probably an error. Possibly xenon hexafluororhodate is a similar case.
 * Since the XeRhF6 article says it's analogous to XePtF6, I think it's problably also not xenon(+1), by the same argument: Xe+, being a radical, would either dimerize or abstract a fluorine atom to give XeF+. So I think we should remove xenon(+1), and have an explanatory note stating the status of these two compounds and why xenon(+1) is excluded. Double sharp (talk) 14:30, 1 March 2015 (UTC)
 * Done. Burzuchius (talk) 14:51, 2 March 2015 (UTC)
 * There is some information about XeF: observed, disputed , then some other data appeared — is it an exciplex or not necessarily? Burzuchius (talk) 16:39, 21 May 2015 (UTC)

Barium(+1). In barium platinides, BaPt, Ba3Pt2, and Ba2Pt, the reported oxidation states of platinum are −1, −1.5, and −2 respectively. So barium should have +1. Or are these compounds electrides?
 * Ba2Pt is an electride (Ba2+)2Pt2−·2e−, according to Jansen's 2005 paper. Double sharp (talk) 14:21, 1 March 2015 (UTC)

Hafnium(+1). I have added an article about HfBr, but I cannot exclude the possibility that it is an electride like ThI3 or Lu monochalcogenides. However, there is also an article about hafnium monohalides in the molecular phase (see also ). So, which article is valid?

Iridium(+7). Has IrF7 actually been synthesized? However, Ir(+7) is also mentioned in something else. Burzuchius (talk) 13:18, 24 February 2015 (UTC)
 * Changed the ref for Ir(+7) to mention [(η2-O2)IrO2]+ instead. Double sharp (talk) 10:15, 3 March 2015 (UTC)


 * Additionally: Ti(−1) and Zr(−1) are often mentioned in bipyridine complexes, but, according to this paper, they should in fact be Ti(+3) and Zr(+4).
 * In that case, I think the mentions of Ti(−1) and Zr(−1) ought to be removed. Double sharp (talk) 15:16, 2 March 2015 (UTC)
 * Done. Burzuchius (talk) 21:36, 2 March 2015 (UTC)


 * Is platinum(+3) a common oxidation state? Burzuchius (talk) 14:36, 24 February 2015 (UTC)


 * Pt(III) is uncommon. Unbolded. Burzuchius (talk) 14:51, 2 March 2015 (UTC)


 * Sc, Y, lanthanides, and Ac. AFAIK most seemingly divalent compounds of these elements (except Sm, Eu, Yb and in some cases Nd, Dy, Tm) have electrons in the conduction band. If we do not consider them to be electrides, then Lu(II) and La(I) (for LaI) should be added. But if we do, then La(II) and Gd(II) should possibly be excluded. Holleman&Wiberg's book does not mention them, however, this review (in Russian; information in English) does (has it been refuted?). Ce(II) and Pr(II), according to Holleman&Wiberg, appear only in alkaline earth solutions. Webelements mentions CeF2 and PrF2, but I haven't found information about them anywhere else. Sc(II) AFAIK exists in CsScCl3. Y(II) is mentioned in the same review as La(II) and Gd(II). This article mentions Y(+2) and Y(+1) in the gas phase. For +1, ScCl, YCl, LaCl, GdCl, and TbCl are sometimes mentioned, but are these formulas correct? Greenwood&Earnshaw say that these compounds should also contain hydrogen. The Wikipedia article Lanthanide states that LaI is the only known monohalide. For sesquichlorides I don't know, whether they contain fractional oxidation states, mixed oxidation states, or are electrides.


 * As for alkaline earth solutions, lists all lanthanides except Pm and Lu; but Holleman&Wiberg's book lists all except La, Gd, Lu. La(II) and Ce(II) have also been observed in some organometallic compounds; see  (p.332),, , , and . Burzuchius (talk) 20:44, 8 March 2015 (UTC)


 * As for HfBr, it is a conducting substance, like ZrCl, ZrBr or HfCl; however, I have never found mentioning it as an electride. Burzuchius (talk) 18:11, 1 March 2015 (UTC)


 * I am not sure if there exists ScCl, but here are some articles about Sc(I):, . Burzuchius (talk) 20:09, 4 March 2015 (UTC)


 * Sc(I) and Sc(II) have been observed in some organometallic compounds. Added examples to the article Scandium. Burzuchius (talk) 20:44, 8 March 2015 (UTC)

Lead(−3). The compound Ba5Pb3 has been reported to contain [Pb2]6−, for example:. But in the article, Ba5Pb3 was refuted and discovered once again, with a different crystal structure. If you have access to the article, please tell me whether the ionic structure of Ba5Pb3 is still valid. Burzuchius (talk) 21:31, 3 March 2015 (UTC)

Ca−? It is interesting! I have found also these articles: about Sr and Ba and  about Ra and actinides. By the way, physicists deal with such ions as He2+, Ca6+, Ca10+, or Dy66+, but I don't think they should be included in the table. I guess that Ca10+ in a chemical environment will immediately become Ca2+ if its speed is much less than the speed of light, but Ca− is stable, so it can form compounds similar to alkalides? Burzuchius (talk) 12:35, 4 March 2015 (UTC)
 * Yup, I wouldn't have put in Ca− if not for the fact that it was mentioned as stable. Double sharp (talk) 13:20, 5 March 2015 (UTC)

There is an article called A brief introduction to transition metals in unusual oxidation states. Burzuchius (talk) 20:09, 4 March 2015 (UTC)

Plutonium(+8), americium(+8), curium(+8). After the claim of CmO4, there has appeared this article: which seemingly states that Cm(VIII) does not exist. This article seems to state that Pu(VIII) and Am(VIII) do exist but Cm(VIII) and of course Np(VIII) do not. Burzuchius (talk) 20:44, 8 March 2015 (UTC)

Gallium(−2, −4, -5). The paper (in German, p. 72) seems to state that gallium exhibits oxidation states −2, −4, and -5(!) in the magnesium gallides MgGa, Mg2Ga, and Mg5Ga2, respectively. One more article mentioning gallium(−2, −4):. Burzuchius (talk) 21:14, 9 March 2015 (UTC)

Titanium(−1) has been reported not only in bipyridine complexes, but also in some other ones, but maybe it is the same error, I don't know.


 * Ti(−1) exists. I think the article, which distinguishes innocent ligands from non-innocent ones, does not mistake. That article also gives an example of Mn(−2), different from the one listed in Greenwood&Earnshaw and Holleman&Wiberg (they list [Mn(phthalocyanine)]2−; is it really [Mn(H2Pc)]2− and not juct [MnPc]2−, which would give Mn(0)?). Burzuchius (talk) 18:24, 3 April 2015 (UTC)

Gold(+4) has been reported, but there is some doubt about its existence, see .Burzuchius (talk) 16:21, 27 March 2015 (UTC)

Ruthenium(−1). There is the anion [Ru2CO8]2−, but according to, it has an asymmetrical structure, so I wonder whether this ion contains ruthenium(−1) or mixed oxidation states. However, according to, the symmetrical anion [Ru2CO8]2− has also been observed. Burzuchius (talk) 21:50, 10 May 2015 (UTC)

Lithium(−1). Ionic lithides are not known, but what about molecular ones? In the gas phase, there exist NaLi, KLi , RbLi , and CsLi , the last two having large dipole moments. If the bonds in these compounds are polarized towards Li, then the oxidation state of Li is −1. Is it true that Li is the negative pole in these compounds? (However, in the solid phase under high pressure, Cs is predicted to be anionized: ). Burzuchius (talk) 16:39, 21 May 2015 (UTC)

Things mentioned in the element infoboxes but not here
Kr(+1), Xe(+1), Ce(+1), Sm(+1, +4), Eu(+1), Dy(+1), Ho(+1), Er(+1), Yb(+1), and Lu(+1) are in their respective infoboxes, but not in this list. Annoyingly none of them are referenced in the infoboxes. Also Au(+4) was in but that's already been questioned above, so I did not hesitate to remove it.

Also, for some reason the Zn infobox mentions 0 explicitly. I wouldn't have expected that to be mentioned explicitly in Zn's case! Now W's infobox gives 0, which makes sense (W(CO)6), but then why not the Cr and Mo analogues? Re, Os, and Ir also give 0; so does Sg, but that makes sense as Sg(CO)6 is known experimentally.

What counts as a common oxidation state? Re(+4) is listed here as its most common state (naturally, this "common" is in the context of Re), but Re(+2, +6, +7) are comparable. This list also bolds things like Kr(+2) and Rn(+2); I didn't in the infoboxes, as this is silly if you show 0 as well for these elements. Double sharp (talk) Double sharp (talk) 10:34, 2 September 2015 (UTC)


 * As for lanthanides{+1), NIST Chemistry WebBook gives LaH, YbH, LuH, LaF, CeF, NdF, SmF, EuF, GdF, DyF, HoF, ErF, YbF, LuF, PrCl, NdCl, SmCl, EuCl, DyCl, HoCl, and YbCl, and also cyclic (LaH)2, (CeH)2, (PrH)2, (GdH)2, (TbH)2, and (LuH)2 (with 3-centre bonds?). also gives some gaseous diatomic molecules, including  LaCl.


 * As for samarium(+4), NIST gives SmH4. This Russian article also mentions Sm(IV). However, I have not found more information about it.


 * As for Kr(+1) and Xe(+1): NIST has monohalides, but aren't they exciplexes? See also Xe(+1) above on this talkpage.Burzuchius (talk) 18:09, 5 September 2015 (UTC)

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Actinium(II)
This supposedly occurs in AcH2, but the actinium article states that its structure is analogous to LaH2. If so it should really be an electride, like LaH2, and would therefore be an actinium(III) compound. Double sharp (talk) 02:03, 6 August 2016 (UTC)

Pu(VIII)
The claim of existence of Pu(VIII) is sketchy and not widely accepted; see 10.1021/acs.inorgchem.5b01540 for some theoretical studies. The same is probably true for Am(VIII), which just like Fe(VIII) and Cm(VIII) has not been confirmed by any other group. I am going to remove them. Double sharp (talk) 05:32, 22 November 2016 (UTC)

a surer example of Pu(II)
https://www.chemistryworld.com/news/plutonium-gets-another-oxidation-state-added-to-its-arsenal/3006982.article Double sharp (talk) 15:34, 25 March 2017 (UTC)

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Pd(VI), Pd(V), Ag(IV)
Pd(VI) was reported in, but later it was shown that its oxidation state is actually +2, see and. Then Pd(VI) was again reported in PdF6 in, but subsequently disproven, see.

Existence of Pd(V) and Ag(IV) is also doubtful, see. Burzuchius (talk) 20:12, 29 July 2017 (UTC)
 * Removed all three. Thank you! Double sharp (talk) 04:40, 30 July 2017 (UTC)

Iridium(IX) and other gas-phase-only states: should they count?
Upon investigating the sources for IrO4+, I noticed that nobody appears to have reported an isolable compound. I'm not sure that oxidation states that can't be isolated in condensed phases should "count" as far as this and other lists are concerned, because for instance a bare iron nucleus as a cosmic ray is formally Fe(XXVI) (similarly for other HZE cosmic rays, or for ionised atoms at high temperature) and even counting only molecular ions there's some ions with really dodgy oxidation states (He2+, for instance). Is there some criterion that would include IrO4+ but wouldn't open the floodgates? Has IrO4+ been isolated in a condensed phase (in which case a source for specifically that should be added)? I'm just wondering where we should draw the line. Magic9mushroom (talk) 11:13, 7 August 2017 (UTC)
 * The annoying thing is that everybody seems to be reporting it as a new oxidation state of IX in spite of this problem. Perhaps there is some (if small) excuse for this, because [IrO4]+[SbF6]− is expected to be a stable, isolable salt in bulk, but I would agree with you that it is a bit dodgy. Another dodgy one is CoV, which AFAIK is only known in the gas-phase cation [CoF4]+. Where this runs into difficulties is that I have not yet seen a paper that remarks on this problem, especially that of opening the floodgates to UXCII. Double sharp (talk) 11:29, 7 August 2017 (UTC)

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Argon - +2?
https://en.wikipedia.org/wiki/Template:Periodic_table_(valence) lists argon as +2.

However, here, it's 0.

What's going on? We need to make these two consistent. 8.40.151.110 (talk) 00:51, 3 April 2017 (UTC)
 * Argon_compounds talks about ArH3+ existing and having a structure that sounds like it could be Ar(II). DMacks (talk) 01:39, 3 April 2017 (UTC)
 * The status of things like argon compounds and what valence to assign Ar here is complicated by the fact that no one has really determined a value for the Pauling electronegativity of Ar. This makes it a bit difficult to define what exactly the oxidation states in Ar compounds are supposed to be. The 6d transition metals also have this problem, but given that the compounds given here are with clearly nonmetallic elements like O, Cl, and the admittedly more equivocal Se, I think it's not so much in doubt. The trend seems to suggest a value almost as high as that of O for Ar. In the absence of a good source for this I'm inclined to switch the valence table to list argon as 0. Double sharp (talk) 08:55, 3 April 2017 (UTC)
 * Okay, argon is now 0. There are predictions of Ar(II) in compounds like [ArF]+[AuF6]−, so we could conceivably change it back at some point. Double sharp (talk) 08:56, 3 April 2017 (UTC)
 * Sounds reasonable. Always interesting when the "some day someone may well publish something new, and we update accordingly" comes to pass. DMacks (talk) 12:47, 3 April 2017 (UTC)
 * Personally, in cases where no Pauling electronegativity is available (such as He, Ne, Ar, and the transactinides), my advice would be to substitute the Allen electronegativity, since the latter is available for all elements; in this case, since this method also gives argon an oxidation state of 0 for both of its known compounds (HArF and ArCF22+), I'm agreeing with Double sharp here. Whoop whoop pull up Bitching Betty &#124; Averted crashes 16:53, 4 April 2017 (UTC)
 * By the way, IUPAC now recommends using Allen electronegativity, not Pauling . Although I see that Allen electronegativity also has some flaws. I think that a better way for constructing a scale of electronegativity would be: first compare the elements (try to construct an electronegativity series for all the elements), and only then assign numbers.Burzuchius (talk) 17:10, 4 April 2017 (UTC)
 * That's the way I developed this scale. Droog Andrey (talk) 12:31, 31 March 2018 (UTC)
 * Holy cow - the IUPAC website specifically mentions the upcoming need to edit the Wikipedia page on electronegativity in order to accommodate forthcoming edits to the Goldbook! Whoop whoop pull up Bitching Betty &#124; Averted crashes 17:17, 4 April 2017 (UTC)

How would Cs(-I) exist?!?!?
Cs is the least electronegative element (Fr is proven to have EN>0.79). So how? Alfa-ketosav (talk) 11:29, 24 April 2018 (UTC)
 * It is highly likely that alkali metal anions exist in very concentrated metal–ammonia solutions through the reaction M− M+ + 2e−. The compounds involved for Na, K, Rb, and Cs are M+C222M−, where the alkalide ions are protected from the polarising ability of the cation by the cryptand that surrounds the cation. See 10.1002/anie.197905871 for more information. Double sharp (talk) 12:06, 24 April 2018 (UTC)
 * "Alkalide" is our lead article on these sorts of ions. DMacks (talk) 20:50, 24 April 2018 (UTC)

Oxidation state 0
What I miss in your list is the occurence of diverse elements having oxidation state 0 in compounds. Esp. Metal carbonyls as Fe(CO)5 show the central atom in oxidation state 0. --Heavy Metal Chemist (talk)(german WP) 14:05, 23 September 2016 (UTC)
 * Fair point. But since it is also automatically present for elements, we need some way of distinguishing trivial cases of oxidation state 0 (such as Be or F2) from interesting cases (such as Fe(CO)5 or Ni(CO)4). I suppose I could amend this to only include oxidation states encountered into compounds, but (1) it's a little arbitrary, since oxidation states are equally defined for single elements, if trivially; and (2) the amount of work that would be needed to add every single possible example to such a list would be somewhat terrifying, given that this list does not restrict itself to common oxidation states, and considers just about everything (including such oddities as NbCl and [IrO4]+) that has been seen in a compound, however unstable (like transient [PoO2]+) to be fair game. Double sharp (talk) 14:42, 23 September 2016 (UTC)
 * Every single possible example wouldn't be required–one will do. I mention this because I just happened to read in Wiberg that Ca forms compounds in which its oxidation state is apparently zero, such as calcium hexammoniate, Ca(NH3)6. IIRC HOF is an example for oxygen. Sandbh (talk) 09:53, 21 February 2017 (UTC)

I just gave Symbol its own column (like in other lists of elements). That emptied column "0". (Please leave it. Symbol doesn't belong as a spaceholder for column "0". If Oxidation state 0 is "trival" (available in compounds of every element), please just tag every element with 0, or else just delete column "0".)

Every element exists in oxidation state 0, so that is not a good use of column 0. But several chemical compound articles mention elements that have oxidation state 0 in those compounds. I tagged those elements in column "0". Maybe every transition metal that forms coordination complexes has oxidation state 0 in some of them. Maybe every element that forms simple or complex metal carbonyls has oxidation state 0 in some of them. (Maybe every element can have oxidation state 0 in compounds - in that case please just tag every element with 0, or else just delete column "0".)

Calcium hexammoniate might or might not have Ca(0). As a coordinated or solvated metal, it suggests 0, but it seems to want to be charged. As sodium hexammoniate forms, the blob releases an electron and becomes an ion (at least in water):
 * Na + 6 NH3 → [Na(NH3)6]+, e−

Maybe some Xenon compounds have Xe(0)? Looking for these, I noticed disodium helide - does that have He(-2)? I can't find aricle mentions or references; not ready to apply the oxidation-state rules to list these with confidence. -A876 (talk) 18:59, 25 October 2018 (UTC)
 * Xe(0) exists in the tetraxenonogold(II) ion. Na2He consists of 2Na++He0+2e−. Burzuchius (talk) 19:38, 25 October 2018 (UTC)

Check values with Infobox values
I have created page Template:List of oxidation states of the elements/2018_tablecheck. It has the table as of today, and also the OS values as present in the infoboxes (, data in Infobox element/symbol-to-oxidation-state). Talk is central at WT:ELEMENTS#List of oxidation states check. -DePiep (talk) 18:19, 11 November 2018 (UTC)

Caesium polyfluorides
Caesium can form polyfluorides in higher oxidation states, such as +5 in CsF5. (doi:10.1038/nchem.1754 ; doi:10.1038/srep07875) --Leiem (talk) 10:01, 16 December 2018 (UTC)
 * They are still hypothetical. Burzuchius (talk) 10:04, 16 December 2018 (UTC)

Propose technical change
I propose to make a technical change: the table can use a subtemplate for each element row, that takes data input (OS-values, references) and does the row-formatting out of sight.

Example beryllium:
 * &rarr;
 * &rarr;

The advantage is that the table is easier to maintain, because only data is in view, no table formatting code. Also, the check with the infobox o.s.-values will be easier.

If OK, I will change the table in one go (preserve os-values and references of course). , ok? -DePiep (talk) 13:43, 16 February 2019 (UTC)
 * See also sandbox (with tests and main table check). -DePiep (talk) 13:45, 16 February 2019 (UTC)
 * OK. Burzuchius (talk) 14:59, 16 February 2019 (UTC)


 * Page version that has been transposed: into new setup Template:List of oxidation states of the elements:.
 * Testcase where old and new version are checked: (values and refs must be the same) Template:List of oxidation states of the elements/sandbox
 * Visually checked: value list the same, bolded values the same, references the same. -DePiep (talk) 09:39, 17 February 2019 (UTC)


 * ✅. New table setup is live now. Changes should be made in Template:List of oxidation states of the elements (parameters in the new row format). -DePiep (talk) 10:01, 17 February 2019 (UTC)

DOI error
I've traced the error to this template, but while it shows up here, I can't find where it's coming from to fix. The cite appears in Infobox_copernicium under the name "Haire". It has the doi value 10.1007/978-3−642-37466-1_8, which is wrong. The correct value is "10.1007/978-3-642-37466-1_8". Please fix.-- Auric   talk  17:19, 20 May 2019 (UTC)
 * Did to Infobox_element/symbol-to-oxidation-state resolve it? DMacks (talk) 18:08, 20 May 2019 (UTC)

Source check wrt Sc(0), Y(0)
The list now uses reference (ref name="Cloke1993", subscription req.):
 * All lanthanides except Ce, Pm, Eu, Tm, Yb have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see

I cannot check the source. Since Sc and Y are in the title, could someone check & confirm that Sc and Y are not listed in there as having a (0) value observed? Interestingly, Sc(0) has been observed by a different source mentioning ... N. Cloke; Y(0) is listed but not sourced. -DePiep (talk) 09:06, 21 September 2019 (UTC)
 * Sc(0) and Y(0) are listed. Added the link for Y(0). Burzuchius (talk) 11:36, 21 September 2019 (UTC)

Coordinating edits with Infobox
If the list template is edited with a documented oxidation state, should the Infobox be edited also? Is there a "tule" for that to assure accuracy? Thanks! Olthe3rd1 (talk) 14:29, 4 June 2021 (UTC)
 * Do you mean the infobox of the element itself? Those are all generated by Template:Infobox element/symbol-to-oxidation-state, which indeed does not appear to have any automatic cross-checking. I wonder if that infobox template can be rewritten to parse the data from this master list here? DMacks (talk) 14:38, 4 June 2021 (UTC)

Yes, the edits are not transferred to Template:Infobox element/symbol-to-oxidation-state. This is what Ivam asking about coordination with this list. Olthe3rd1 (talk) 14:45, 4 June 2021 (UTC)
 * Pinging User:DePiep, who has a lot of template experience in the chemicals area. Could we have one template that is a giant {switch} to look up data per element, then each infobox can get the one it wants and the master table can pull them all each in turn? DMacks (talk) 16:40, 4 June 2021 (UTC)
 * Good question!
 * Metatemplate Infobox element  reads oxidation states of a single element from Infobox element/symbol-to-oxidation-state (overview), automated and by element symbol.
 * This is compared with this List of OS per element in  List of oxidation states of the elements/datacheck (a maintenance table).
 * In the /datacheck both listswere compared manually by the eye, and a check-status (delta, difference) was added to the Z-column: "ok" or "0" "+1" "+2" for the different value(s) &mdash; to be aligned then by RS. Also, status = "b" indicated that the bold value (ie, the Main OS value) differs.
 * Background: the /datacheck was created in November 2018. User:Burzuchius has cleaned up many entries. ,
 * Maintenance & update (as asked): Today, 11 out of 118 elements have a delta. Since OS's are quite stable in RS's, we have the habit that changes can be applied only when adding a RS. That is: remove or add a value in one or both lists only when you can ref to RS(s).
 * Technically, the editing may be complex (the tables are live) so one can alway ping people here for assistance. -DePiep (talk) 17:13, 4 June 2021 (UTC)


 * So that is:
 * datalist OS (A): List of oxidation states of the elements
 * datalist OS (B): Infobox element/symbol-to-oxidation-state
 * comparing: List of oxidation states of the elements/datacheck (has edit-links to the tables)
 * HTH -DePiep (talk) 17:18, 4 June 2021 (UTC)
 * HTH -DePiep (talk) 17:18, 4 June 2021 (UTC)


 * I see has made changes to the list recently, I guess they need to be synchronised with the INfobox list  (as the OP points to). I cannot judge whether the changes are undisputed (not my depth). -DePiep (talk) 17:24, 4 June 2021 (UTC)
 * I have changed the status, sourced diff now for: Mg(0), Ca(0), Sr(0), Ba(0) . I.e., list B to be updated when refs are OK. -DePiep (talk) 04:36, 5 June 2021 (UTC)
 * Ooh, I did not know about that /datacheck tool. Neat! DMacks (talk) 03:53, 6 June 2021 (UTC)

Zinc 3+?
When I check the reference (#33) given for Zn(III), they do not claim any experimentally obtained compound containing this species. All proposed compounds are rendered only theoretically, and the hexafluoridoaurate in the reference is not the known Zn(AuF6)2 but the unknown Zn(AuF6)3. So, should we keep this oxidation state? (This has since been corrected in the template.)Olthe3rd1 (talk) 23:16, 8 December 2021 (UTC)

Barium(I) reference
Reference 91 (as of January 3, 2022) is listed as documenting Pt(-1) and Pt(-2), but the assigned platinum oxidation states and stoichiometries of the compounds apparently indicate that barium is rendered as Ba(I). This would provide a stable condensed-phase example for Ba(I); please check. Olthe3rd1 (talk) 01:06, 4 January 2022 (UTC)
 * The original paper considers these compounds as sort of electrides, with some of the electrons not assigned to any atom. Burzuchius (talk) 09:00, 4 January 2022 (UTC)

OK. Still the compounds had to be corrected in my recent edit (BaPt is Pt(--1), Ba2Pt is Pt(-2) not vice versa). Olthe3rd1 (talk) 03:03, 10 January 2022 (UTC)

Silver not ok
Silver is listed as OK in the datacheck, but this template and the Infobox disagree on the zero oxidation state. The infobix omits zero even though the WP article on silver itself refers to a carbonyl compound containing Ag(0). Please straighten this out, thank you! Olthe3rd1 (talk) 23:47, 21 April 2022 (UTC)
 * Ag changed into "0" (as diff). To be fleshed out (sourced in A or removed from B). Thanks for this report. This is exactly what this compare-list is for, b/c both are serious lists; we are working to get them aligned, preferably by sources. Infobox silver reads its O.S. data straight from one of these lists; we don't want a third place to maintain ;-) -DePiep (talk) 05:02, 22 April 2022 (UTC)

So now there are 12 rather than 11 elements with differences, and also it is late April instead of March. I appear unable to update the summary section to match this. Thank you. — Preceding unsigned comment added by Olthe3rd1 (talk • contribs) 17:52, 25 April 2022 (UTC)
 * By now, this Template:List of oxidation states of the elements/doc and List of oxidation states of the elements seem to show your edit (into "12 by April") allright. -DePiep (talk) 18:09, 25 April 2022 (UTC)

Many more elements now have a difference. Lithium(0) (claimed to exist in clusters), sodium(0) (in Na3Cl, but it could actually be Na(-1)), aluminum(0) (claimed in carbonyls), bromine(II) (oxygen in BrO assumed to have an oxidation state of +2), Pd(V) (in a complex where Pd is bonded to five silyl ligands). Can these references be checked and the lists reconciled? Olthe3rd1 (talk) 12:31, 15 August 2022 (UTC)
 * Yes, recent edits have added sourced OSs Aug 2022. They should be aligned (presumption: all additions are well sourced and so OK). -DePiep (talk) 12:45, 15 August 2022 (UTC)

Sulfate radical oxidation state
The highly oxidized sulfate radical (SO4•-) has been studied well in organic chemistry within the problem of eliminating harmful pollutants in wastewater. Is the oxidation state of sulfur in this radical really +6 or slightly greater? Where can I find the answer for this in currently-available articles? 171.232.29.250 (talk) 14:08, 19 February 2022 (UTC)


 * Probably sulfur is still S(VI) as in the ordinary sulfate ion SO42-. The electron lost to form the singly charged radicals would come from an oxygen-based MO so the oxygen is no longer exactly in oxidation state -2. Olthe3rd1 (talk) 10:10, 24 August 2022 (UTC)

Oxidatation states in Wikidata
FYI: added to Infobox element/symbol-to-oxidation-state/overview-oxidation-state: Wikidata property for the elements. For example:

DePiep (talk) 20:51, 27 September 2022 (UTC)

Neon(0)
Should Ne(0) be added, as in Cr(CO)5Ne? (, mentioned in Neon compounds.) Double sharp (talk) 11:06, 20 December 2022 (UTC)
 * Perhaps it should. Burzuchius (talk) 15:29, 20 December 2022 (UTC)
 * ✅ Double sharp (talk) 06:44, 21 December 2022 (UTC)
 * Then, should helium also get a 0 from HeH+? Double sharp (talk) 07:48, 21 December 2022 (UTC)
 * I am not sure. Burzuchius (talk) 15:43, 22 December 2022 (UTC)

We also have helium(0), as a high pressure elecride compound. This would resolve one of the remaining differences. Olthe3rd1 (talk) 13:04, 15 February 2023 (UTC)

Reference issue
Reference 149, as counted on 14 May 2023, gives an error and fails to display. Please check/correct. Olthe3rd1 (talk) 22:20, 14 May 2023 (UTC)