Talk:Allotropes of phosphorus

Violet phosphorus
I've made some new images of the crystal structure of violet P, as I could never visualise the 3D structure (how chains link together) from looking at the structure as typically presented.

I'll put them here in case anyone feels like expanding the text on the structure of violet P.

Ben (talk) 20:10, 25 January 2009 (UTC)

Ben - these are fascinating. thanks for making them and putting them here. i don't know enough to do anything with them, but wanted to let you know i appreciate your efforts.Colbey84 (talk) 13:10, 3 March 2016 (UTC)

English version of the german image Phosphor Modifikationen.png
Placing this image was problematic in formatting.

How come there is no octaphosphorus?
You'd think a cube-shaped P8 molecule would be more stable than a P4 tetrahedron, since unlike the tetrahedron, it would have no strain energy (the bond angles would be 90 degrees, which is exactly what one would expect for P-P single bonds in which there was no orbital hybridization).

Yet white phosphorus (which is one of the most easily obtainable forms), is unstable P4 rather than P8, and there is no mention of P8 in the article. Has anyone ever attempted to synthesize P8?

Maybe there is some other reason why the P8 molecule is unstable, but if so, I have no idea what that reason is. Stonemason89 (talk) 12:51, 29 June 2009 (UTC)
 * Lots of people have pondered this very question. And some alkylidyne-substituted derivatives have been reported, I think.  Strain energy is a funny thing since interatomic vectors are not the same as bonds.  --Smokefoot (talk) 13:35, 29 June 2009 (UTC)

A neutral P8 molecule has been synthesized using carbenes. http://www.ncbi.nlm.nih.gov/pubmed/23568344 — Preceding unsigned comment added by Brentonius (talk • contribs) 13:14, 11 July 2014 (UTC)

this was/is really interesting. maybe something more about this should be added to the page? the Non-existence of... section doesn't say very much. and i'm especially wondering if something about the neutral P8 being synthesized should be included? and, if so, perhaps something about why this is important/why it was done/what practical uses it might have, etc??Colbey84 (talk) 13:09, 3 March 2016 (UTC)

Yellow/White and light exposure
White phosphorus is a transparent waxy solid that quickly becomes yellow when exposed to light

The picture seems to run counter to that statement, where the block is white on the outside, except for the corner of newly-exposed inside, which is yellow. From the photo I would have concluded that P4 is normally yellow, but when exposed to light slowly turns white - or is there smoething else going on here? (You'll have a hard time convincing me that the inside of a block has been exposed to more light than the outside has.) Also, the white-to-yellow color change indicates that there is some structural/bonding change that's occurring - does anyone know what happens to cause the color change? -- 140.142.20.229 (talk) 19:17, 29 April 2010 (UTC)
 * I don't know for sure but offer the following explanation: white phosphorus gradually converts to red phosphorus and thus appears yellow. The pictured sample is old and had this transformation (stimulated by heat and light) deep into the bulk, as revealed by the cut. Both white and red phosphorus do oxidize; the oxidation stops at the surface (because of extremely slow oxygen diffusion) and the oxide is white - this is what we see as a whitish tint in the picture. Materialscientist (talk) 03:59, 30 April 2010 (UTC)

Red phosphorus
"Red phosphorus may be formed by heating white phosphorus to 250 °C" vs. "Red phosphorus can be converted to white phosphorus upon heating to 260 °C" aren't those statements kind of contradictory? Red converts to white by heating and white converts back to red by heating again? Something is missing or am I missing something? --Spmoura (talk) 16:55, 1 October 2012 (UTC)
 * I revised the second statement, although I assume that at some temperature the red allotrope would crack back into the white. --Smokefoot (talk) 12:47, 2 October 2012 (UTC)

In the article "Allotropes of phosphorus", the heading "Hittorf's violet phosphorus" should be on the left margin. — Preceding unsigned comment added by 98.245.136.184 (talk) 20:03, 26 April 2013 (UTC)

Convert template
i put the WP convert template in the White Phosphorus - Production and applications and the Red Phosphorus sections. mostly, i looked it up because i was curious at what air temp the white would spontaneously ignite (and i'm used to F measurement). i thought others might be interested, so i put the convert template in. then i also put it in the Red Phosphorus section, but didn't do any more because 1) i thought maybe there was some strange, science-y reason why it hadn't been done before, but mostly because 2) the converter came up with a different figure than was in the original text. (the first temp in the Red Phos. section had F in parenthesis after the C measurement.) i double-checked the conversion, and the converter template was correct. but i wanted to make a note of it here, in case there's something else going on. i left the original text's F measurement in place, but hid it in the html. to make it easier:

Colbey84 (talk) 13:06, 3 March 2016 (UTC)
 * original text - "300 °C (482 °F)"
 * convert template - "300 °C (572 °F)"

Melting, boiling (or sublimation) points of allotropes
What are melting and boiling (or sublimation) points of red, violet and black allotropes of phosphorus under standard pressure? What are Mohs hardnesses of these allotropes? — Preceding unsigned comment added by Krobon (talk • contribs) 18:32, 24 October 2016 (UTC)

Wikipedia is not ...
Here are the references on black phosphorus, It is a rare, some would say esoteric, allotope, yet the referencing is heaviest on this material. And most of that referencing is to primary articles, which is inappropriate. It is possibly a case of undue weight, per WP:UNDUE, WP:NOTNEWS, WP:NOTJOURNAL, WP:SECONDARY. --Smokefoot (talk) 13:54, 7 December 2016 (UTC)


 * That is a lot of references; perhaps more than are needed.
 * I don't understand the issue with "primary" articles, though. Primary sources are always considered more authoritative than secondary or tertiary sources.  — Preceding unsigned comment added by 70.89.176.249 (talk) 22:14, 25 June 2019 (UTC)

Whiskey Pete
Why does Whiskey Pete redirect here? SchmuckyTheCat (talk) 12:21, 28 June 2018 (UTC)
 * It's a version of Willie Pete = military jargon for White Phosphorus. I repointed the link to White phosphorus munitions. Dirac66 (talk) 22:59, 28 June 2018 (UTC)


 * Yes, my parents went through WWII and said the phosphor bombs were really nasty. Now that's the military application, i.e. destruction. Elsewhere I just read that plants (food plants) need phosphor in their early stages to grow good roots or there will be stunted growth of the whole plant. There is obviously a need which is developing into a shortage. In 2008, so the BBC article, phosphor price rose 800%. Maybe throwing it around in bombs is not such a good futureproofing strategy? Apart from that, the layperson could be interested in which kind of phosphorus is needed to grow crops and where that is mined. Have an agricultural section? 2001:8003:AC60:1400:F899:D3E0:FDF3:289E (talk) 05:56, 5 February 2019 (UTC)

Contradiction
Red Phosphorus: "Red phosphorus does not ignite in air at temperatures below 240 °C (464 °F), [. . .]    Ignition is spontaneous at room temperature with finely divided material."

If finely divided red phosphorus spontaneously ignites at "room temperature" (usually considered to be about 20°C), then the statement "Red phosphorus does not ignite in air at temperatures below 240 °C" is manifestly incorrect. If the earlier statement is true, then the statement about spontaneous ignition at room temperature must be untrue.

Which is it? — Preceding unsigned comment added by 70.89.176.249 (talk) 22:11, 25 June 2019 (UTC)


 * Former is presumably the bulk material. Magic9mushroom (talk) 06:18, 24 May 2021 (UTC)

The picture of the four phosphorus allotropes
In the picture, in which the four most common allotropes are depicted, the two right ones are obviously photomontages of the red and violet phosphorus samples in the glass tube on the later picture. So they do not depict violet and black, but red and violet phosphorus. Niike 2010 (talk) 15:25, 19 November 2019 (UTC)

Tetrahedral White Phosphorus
I would like to raise contention about white phosphorus as a tetrahedron. I understand mathematically, the structure is a tetrahedron, however such a description may raise confusion with the specific chemical definition of a tetrahedral molecule being defined by a specific bonding angle of 109.5 degrees symmetrically, a characteristic this phosphorus atom cannot possess due to only having 4 atoms. To avoid confusion it would be better to have a better description. FlogisticatedHeir (talk) 01:15, 22 May 2020 (UTC)

May I suggest acute tetrahedron or equilateral tetrahedron? FlogisticatedHeir (talk) 01:27, 22 May 2020 (UTC)

Uses in matchsticks
If no one objects or points out consensus against it, I will return in a week or so to find sources and add its applications in matchsticks in the relevant sections (white and red). After all, phossy jaw appeared in early Industrial Age in match factory workers, and Berne Convention (1906) was enacted to regulate phosphorus use in matches. Its omission—not even a brief mention—here seems strange. Rotideypoc41352 (talk · contribs) 17:04, 24 April 2024 (UTC)