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Author: Subject: Preparation of elemental phosphorus
jimmyboy
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Nice writeup Strepta - no need for acetylene and steel retorts anymore

[Edited on 17-6-2008 by jimmyboy]
len1
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Its worse than I thought, Al powder is not just watched its restricted. (This is ridiculous, I remember a time it was sold in toy shops.)
LSD25
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Yeah, obviously some concern that suicide bombers were going to start using thermite

Got any nifty suggestions for powdering Al shavings/filings?

Whhhoooppps, that sure didn't work
len1
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 Quote: Originally posted by LSD25 Yeah, obviously some concern that suicide bombers were going to start using thermite Got any nifty suggestions for powdering Al shavings/filings?

As I posted, since the Al is actually liquid at reaction temperature, well mixed fine Al shavings should work. ( They wont work in ammatol so theres a relief our govt is protecting us)

PS That should be ammonal, ammatol is the amnitrate with diesel fuel I think

[Edited on 17-6-2008 by len1]
Magpie
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 Quote: Its worse than I thought, Al powder is not just watched its restricted. (This is ridiculous, I remember a time it was sold in toy shops.)

This is somewhat off-topic but I have to ask: Why are so many chemicals banned/restricted in John Howard land? Was it the bombing in Bora Bora? Or what? Is the meth problem as bad there as in the US?
len1
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 Quote: This is somewhat off-topic but I have to ask: Why are so many chemicals banned/restricted in John Howard land? Was it the bombing in Bora Bora? Or what? Is the meth problem as bad there as in the US?

No not really. We are trailing the world in utilisation of chemicals (I wrote before about my attempts to get Ni here) so we are leading the world in the banning of chemicals. Because (honestly) we want to be leaders in something. Thats how the politicians/media have taught the public to think

We dont have much of a chemical industry -> we can ban chemicals willy nilly.

But it will lead to the above statement with the -> reversed. Its the chicken and egg problem

PS Were rid of Howard (he lost his seat in parliament and his party office) but it'll take a long time to reverse the sense of fear he used to govern

[Edited on 17-6-2008 by len1]
Polverone
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Very nice work, Strepta. I'm a bit envious that you managed to take this to a photo-documented microscale preparation before I did, but I did squander 5 years since I first found mention of aluminum/metaphosphate reductions. Well done!

Garage chemist, I look forward to your upcoming variation on this preparation. Len1, I would be interested in seeing this tried with Al shavings. I have done it on a test-tube scale with chopped-up Al sheet and sodium hexametaphosphate (just watched the P vapor bubbles burst, no product recovery), and a reaction certainly takes place even at a moderate red heat. The reaction seems pretty slow, though. It may be difficult to get good mixing, even with molten Al, as the melt is pretty viscous. Maybe not_important's suggestion to form a mixture of metaphosphates to lower MP/increase fluidity would help things along. Can you get zinc dust, or is that restricted too? I imagine it would work fine at the temperatures you can reach in your electric furnace, and the finely divided zinc may be more tractable than coarser aluminum even if its intrinsic reducing power is not as great.

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LSD25
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As to the banning of chemicals here, I'd be fucking suprised if it were possible to source zinc dust,

Although I just checked an auction site which shall remain unnamed (the one you can't buy a condenser on) and it seems that some of the more onerous restrictions are off glassware at last, so anything is possible

That said, I am seriously interested in the idea of using Al shavings - it is either that or build a small ball-mill and make the powder myself (the paint route will get expensive awful quick).

Would you get the hexacalcium metaphosphate from adding calcium carbonate to the monoammonium phosphate melt? It is of academic interest, I can get Calgon, but others cannot.

Whhhoooppps, that sure didn't work
len1
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Thanks for that info Polverone, I think Ill have to think of ways to get good mixing in the molten mix. I have 100gms of Al powder left me for life so theres a great incentive to make the shavings method work, Im absolutely sure its possible.

Zn powder is not restricted (cold-galving, as its application in a paint base is called here is as Australian as BBQ's so I dont think theyll dare touch it) but are you sure it works? ZnO enthalpy of formation is only 350kJ/mol (for Al2O3 its 555kJ/mol oxygen) so it would have to be at a substantially higher T than with Al. But Zn boils at 910C odd, so on the surface it doesnt seem suitable. (I can see our future chemical curriculum: the alkali elements, the rare-earth elements, the banned elements ...)

[Edited on 17-6-2008 by len1]
Polverone
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The Franck patent that the aluminum reduction method is based upon also mentions the use of zinc as a reducing agent. I have seen a mention much earlier, in the 1855 book Outlines of Chemical Analysis: Prepared for the Chemical Laboratory at Giessen By Heinrich Will, Daniel Breed, Lewis (Google Books) that metaphosphoric acid or metaphosphates will liberate phosphorus when heated before the blow-pipe with a bit of zinc.

I have verified without recovery (like the aluminum sheet experiment) that chopped bits of zinc will cause the liberation of phosphorus from hot fused metaphosphates. Even lead will do it. I think the critical point in going from demonstration to production isn't going to be the reducing power of the metal (within reason), but ensuring that the kinetics and conversion efficiency are optimized for production. Good mixing may strongly influence that (good mixing, or ensuring that oxides are fluxed away to keep exposing fresh metal to the melt).

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Strepta
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 Quote: Originally posted by len1 Its worse than I thought, Al powder is not just watched its restricted. (This is ridiculous, I remember a time it was sold in toy shops.)

len1: By now you've undoubtedly seen the post in the Al Powder Systhesis thread by LSD25. The paper linked provides a wealth of info about producing flake aluminum from Aluminum foil.

I don't suppose you can get magnesium if you can't get aluminum. If you could, you could try to 'cut' the reactivity of the Mg with either Zn or coarse Al. In the experiments I conducted with Mg the reaction mix and phosphorus product exploded out of the tt onto the side wall of my fume hood with a loud BANG but did not break the tt or destroy the setup in any way. This leads me to speculate that this reaction could be toned down fairly easily.
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Mg and Zn can react in the gas phase at unusually low temperatures. Something to think about.

Tim

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chloric1
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 Quote: Originally posted by Polverone Very nice work, Strepta. I'm a bit envious that you managed to take this to a photo-documented microscale preparation before I did, but I did squander 5 years since I first found mention of aluminum/metaphosphate reductions. Well done! Garage chemist, I look forward to your upcoming variation on this preparation. Len1, I would be interested in seeing this tried with Al shavings. I have done it on a test-tube scale with chopped-up Al sheet and sodium hexametaphosphate (just watched the P vapor bubbles burst, no product recovery), and a reaction certainly takes place even at a moderate red heat. The reaction seems pretty slow, though. It may be difficult to get good mixing, even with molten Al, as the melt is pretty viscous. Maybe not_important's suggestion to form a mixture of metaphosphates to lower MP/increase fluidity would help things along. Can you get zinc dust, or is that restricted too? I imagine it would work fine at the temperatures you can reach in your electric furnace, and the finely divided zinc may be more tractable than coarser aluminum even if its intrinsic reducing power is not as great.

Polverone- you talk about viscosity, what about a flux? Anyone ever melted pyrophosphates? They are less condensed and possibly they can at least be more fluid through the coarse of the reaction before condensing to higher phosphates. Potassium soaps are more liquid that sodium so maybe adding potassium pyrophospate might do the trick. I am shooting in the dark here.

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Strepta
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Tip of the hat to not_important; I tried boron trioxide (from boric acid by heating) in place of silica according to:
6NaPO3 + 10AI + 3B2O3 = 6NaBO2 + 5Al203 + 3P2 and had better yield in terms of less solid residue (ash) after the reaction.

Stoichiometry of the above equation calls for a ratio of calgon/Al/silica of 2.93/1.29/1. I mixed it accordingly and ground it thoroughly in a mortar. The B2O3 is quite hard after it cools and a bit of work is required to pulverize it. The end result is a mix which acts as a fluid, rocking back and forth if swayed and spurting to the top of the tube if the bottom is rapped sharply on a hard surface. Again I took 3 grams of this mix and heated it at the bottom of a pyrex test tube, the other end of which was wrapped with a damp piece of paper towel. CO2 was used a a protective atmosphere and the exhaust was routed through a half full 100 ml cylinder of H2O.

Heating of the tt was via a meker burner. The first noticeable difference in using B2O3 was that the edges of the mix began to shrink and curl before the reaction started, a result of the B2O3 starting to flow.

Once initiated the reaction was, again, self-sustaining, but noticeably slower -12 to 15 seconds- than the 3-4 seconds previously observed with silica.

Yield of P was .265 g from .512 available (identical result from 2 tries). The ash, however, was smaller and almost identical mass in both tries. The residual was .500 g less the initial mass (2.500 vs 3.000). If all the difference is attributed to released P, the efficiency of the reaction is ~98%. the missing 50% P could possibly be lost as P2O5 (quite a bit of gas escapes from the 100 ml cyl. during the reaction.

As not_important suggested, more could be done using a mix of borosilicates and metaphosphates to effect melting at even lower temperatures, if one is so inclined to experiment. I think I will concentrate on a better method of capturing and condensing the vaporous P before it escapes.
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 Quote: Originally posted by len1 Its worse than I thought, Al powder is not just watched its restricted. (This is ridiculous, I remember a time it was sold in toy shops.)

Len i read this about a week ago and found it strange, i thought it was available in Melbourne but wanted to establish that definitely before i responded. Anyway, well, yes i have just come from
Barnes&Co, Swan St,Richmond, VIC, online www.barnes.com.au
They have 5kg, 1kg and 500g ultra fine mesh al powder for $59,$20, and $12 respectively and it is ultra ultrafine. They also have other metal powders made from i think a reduction process, let me remember, Sn, Cu, Brass (three kinds??), Iron, Al (ultrafine and course). The store is a supplier to the resin casting industry and the metal powders make polyester resins and such look metallic. I shop there for the disposable nitrile gloves and dry IPA. However i noticed today they have four types of organo metallic catalysts avaiable neat, aryl mercuric carboxylate (or slow curing polyurethanes, dibutyl tin dilaurate (for curing silicones), organo tin carboxylate and a platinum one for curing food grade silicones. I directly asked about their knowledge of the legality of the Al powder, saying i had read in a forum it had become restricted because someone had perhaps made explosives from it. The lady (the daughter of Mr Barnes the stores founder) then said that sounds like crap as they sell it in paint stores, i left it at that with her, however i thought i'd let you know she thinks you're full of shit! Anyway thought you might like to know. len1 International Hazard Posts: 595 Registered: 1-3-2007 Member Is Offline Mood: NZ 1 (goal) - Italy 1 (dive) Yes indeed, this is available! However I can assure you that what I wrote wasnt an off-the-cuff comment, I had actually been told by a reputable chemical company (not a centre stocking trade chemicals) that Al is restricted. Moreover the lady said it was restricted to such an extent that they would not sell it except on an account (after I told her I needed it for my hobby not my work). They sell a lot of chemicals with lower grades of restriction on the production of a drivers license and presentation of EUD - but not Al powder! It appears now that our authorities are all over the shop with their newly introduced bans on chemicals. As for paints, I had investigated that as a possible source after the above incident. There is no certainty so called aluminium colourede paints actually contain Al, or that is pure. What is worse, I weighed aluminium coloured paints and could find no noticeable density difference with non-metal paints (density of Al is nearly 3) which suggests there is little Al in them if any. PS A further thought open for discussion. You have given the shops name, is that good? On the one hand I hate secretive types who dont reveal their 'sources' (and return them the favour by not giving them any help). On the other hand if this forum is watched (as it undoubtedly is at least in the US) these people might now try to bring 'its trade practices into line', as they have done with the chemical suppliers, to the detriment of non-account chemists here [Edited on 7-7-2008 by len1] Panache International Hazard Posts: 1248 Registered: 18-10-2007 Member Is Offline Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein I thought we all readily discussed suppliers and the like here, if because of that the police request a perfectly legitimate company from trading an item then that is fine in my opinion, a mistake had been made by the company. Most large Australian chemical suppliers have at least a permanent part time if not full time police member in their sales office and as such those places readily are updated to changes in the law. This is prudent i believe, as i think it prudent that there is some monitoring of this site, if only to slow morons with a bible or koran making something that goes bang in a public place. I'm am truly shocked that Aluminum powder has gone past the point of the being restricted as per the Code of Practice and is now banned for all except account holders, that is quite extreme. Is liquid oxygen restricted? Imagine if a truck of liq O2 collided with a coking coal truck. It would be chaos because the drug squad would try and pull jurisdiction over the terrorist squad because coke was involved but really it was just a traffic accident. [Edited on 7-7-2008 by Panache] [Edited on 7-7-2008 by Panache] len1 International Hazard Posts: 595 Registered: 1-3-2007 Member Is Offline Mood: NZ 1 (goal) - Italy 1 (dive)  Quote: Most large Australian chemical suppliers have at least a permanent part time if not full time police member in their sales office and as such those places readily are updated to changes in the law. I thought I could tell your jokes - but here Im not sure - please help me - youre not serious???  Quote: This is prudent i believe, as i think it prudent that there is some monitoring of this site, if only to slow morons with a bible or koran making something that goes bang in a public place. Well this has two implications. First as youd know the police's and jurisdiction marks in chemistry are not high enough to place them in the best position to differentiate between the former and you. On slow days, you might just do. Second Al powder can indeed be used to make bang (and it doesnt care about the place). So if thats the criterion, its the end of chemistry right there. Or maybe I got you wrong and you wrote all the above to scare the undesirables away. To be honest I dont think there'll be a rush to the place you mentioned to buy Al powder [Edited on 8-7-2008 by len1] Panache International Hazard Posts: 1248 Registered: 18-10-2007 Member Is Offline Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein Quote: Originally posted by len1  Quote: Most large Australian chemical suppliers have at least a permanent part time if not full time police member in their sales office and as such those places readily are updated to changes in the law. I thought I could tell your jokes - but here Im not sure - please help me - youre not serious??? Unfortunately this is absolutely true. Actually let me qualify, i know each largish company has a liason type officer who may have at most three companies they deal with so their presence is constant and frequent. However depending on the circumstance, a large company say like Sigma in Australia will have both the police person all the sales staff know about, they do the updating etc etc. They will also have a second undercover sales staff, who monitories staff. Only a few of the senior exec's know who this person is. That's all i know, i have heard more frightening things, but find them unbelievable.  Quote: This is prudent i believe, as i think it prudent that there is some monitoring of this site, if only to slow morons with a bible or koran making something that goes bang in a public place. Well this has two implications. First as youd know the police's and jurisdiction marks in chemistry are not high enough to place them in the best position to differentiate between the former and you. On slow days, you might just do. Second Al powder can indeed be used to make bang (and it doesnt care about the place). So if thats the criterion, its the end of chemistry right there. Or maybe I got you wrong and you wrote all the above to scare the undesirables away. To be honest I dont think there'll be a rush to the place you mentioned to buy Al powder [Edited on 8-7-2008 by len1] I guess i was over-summarising my position on the issue above as this was kind of an aside in an already very long thread and as such what i said sounded a little oversimplified. I will however defer my actual position on this matter until a more appropriate opportunity arises. This thread is about P, which i have nothing to add to given the only time i needed 2g's of red phosporous i spent four hours scratching off the 'matchheads' only to be told (luckily i asked) by Sauron that the red P was in the strikers!! Ha. Whats in the matchheads anyway, they are red, its so confussing. 497 International Hazard Posts: 778 Registered: 6-10-2007 Member Is Offline Mood: HSbF6 The red is just dye IIRC they're mostly KClO3, glue, and ground glass for sensitizing. I'm probably forgetting something else. Edit: I'm confused as to why it would be good to use a mix of Ca and Na metaphosphates. In US patents 4725368 it states that sodium-calcium metaphosphate (1:1 ratio) melts around 750*C. That's much higher than 550*C stated for straight sodium metaphosphate. Calcium metaphosphate melts above 1000*C IIRC. Maybe when mixed at a different ratio they for a eutectic? I did find another patent US 5529960 that has a bunch of information on low melting metaphosphate glasses, some with transition temperatures as low as 230*C. I don't know how that compares to "melting point" though since they are a glass after all. The simplest and easiest one I have seen so far is (in molar %): 46% P2O5 4% Al2O3 25% K2O 25% Na2O It has a transition temperature of 260*C, I don't know how much of an effect this would have on the reaction, but I can't see how it could hurt. It might require an initial melting of 1000*C though... Now if this was combined with a lower melting reducing agent it might react at a much lower temperature. Tin comes to mind, being amazingly low melting and more reducing than lead. An added bonus is it's very easy to get as solder. Also are there any other options besides B2O3 and SiO2? Second edit: I don't know if this would work or not, but there are some very low melting oxide eutectics. US patent 4743302 and 5145803 contain some good data. There are some with a softening point of down to 225*C. The simplest and most OTC one I have found yet consists of about 87% PbO and 13% B2O3 and has a softening temperature of around 330*C and melting at 450*C. If I'm thinking right it should form a sodium plumbite/borate mix after the reaction. PbO melts at 888*C. For the absolute lowest temperature a V2O5/PbO eutectic can be used, but V2O5 is not too easy to get, and I don't think lower softening temps would help that much anyway. So if all goes according to planed (unlikely) this should be the reaction for the majority of components: 4Na(K)PO3 + 6Sn + 2PbO ---> 2Na(K)2PbO2 + 6SnO2 + P4 Should proceed at 300-400*C. Maybe it could work? [Edited on 9-7-2008 by 497] [Edited on 9-7-2008 by 497] DJF90 International Hazard Posts: 2266 Registered: 15-12-2007 Location: At the bench Member Is Offline Mood: No Mood Using solder would actually be a great idea... Not only would it melt at a sufficiently low temperature (lower than lead or tim on its own IIRC?), there are two reducing agents present (it was noted earlier that the reaction would run with lead). Solder is fairly cheap too, and can be bought "fluxed" or "flux-free", depending on whether a flux would be needed and/or the purity of the end product? bigbigbeaker Harmless Posts: 12 Registered: 12-6-2008 Location: Ilkast, DE Member Is Offline Mood: No Mood Harvesting Aluminum from Paint len1 - See Richard Nakka's website for details. I used RustOleum aluminum enamel and some cheaper brands when I was a kid. The AL payoff is good especially if you don't have another source. Nakka says " Fortunately, in the true spirit of experimental rocketry, a source of flake aluminum is as close as your nearest Home Depot or hardware store. Aluminum paint is largely a mixture of linseed oil and metallic aluminum flake. According to various MSDS's, such paint contains 20%-30% aluminum, by mass." The link is http://www.nakka-rocketry.net/igniter.html#Aluminum. Here in the US we can buy all the AL powder we want off Ebay or from a pyro supplier. The only restriction is that most suppliers won't sell AL in the same order with potassium perchlorate because flash powder is the intended product. And there is a limit on suppliers selling more than two pounds per year to any one customer. Since I'm not a flash powder maker, I don't care except that restrictions always get tighter as the years pass. They are never relaxed. The sodium and phosphorus guides are great. Fine work, great pics, totally enjoyable reading. Thank you. JohnWW International Hazard Posts: 2849 Registered: 27-7-2004 Location: New Zealand Member Is Offline Mood: No Mood Illegal to sell aluminium powder in Oz, and the Pigs actually try to enforce that?? (BTW The Australian Pigs are as corrupt as hell, especially the New South Wales, Queensland, Victoria, and Federal Pigs, while the West Australian Pigs are more noted for their brutality, so you could probably bribe them). That is utterly pointless, because all you have to do to make your own is to get some offcuts of aluminium joinery extrusions (which would otherwise be sent for recycling by melting-down at a foundry) from any maker of aluminium windows and doors (of whom there are hundreds around), and grind them into powder by holding them onto the face of an electric grinder or grinding wheel. Or, you could buy aluminium ingots from a recycler, or from the aluminium smelter at Tiwai Point, near Invercargill, New Zealand, and grind those down. (I think there may also be an aluminium smelter in Tasmania). [Edited on 11-7-08 by JohnWW] 497 International Hazard Posts: 778 Registered: 6-10-2007 Member Is Offline Mood: HSbF6 So today I went to the store in search of some NaPO3. The only Calgon they had was non phosphate crap, not surprising. They did have another brand "White King" water softener that stated Na2CO3 and Sodium tripolyphosphate as ingredients. I bought it, for$5 I figured I couldn't go wrong. I haven't been able to find an MSDS for it so I don't really know what all is in it. It consists of a mixture of clear crystals a bit larger than table salt and opaque somewhat amorphous granules of variable size. The crystals are much more soluble and I determined that they are the at least substantially Na2CO3. I purified about a kilo of it by simply adding minimum amount of water to dissolve most of the crystals and then filtering out the undissolved suspected tripolyphosphate. It seems to work well.

My question is will the tripolyphosphate work? If it won't, how can I convert it to NaPO3? It melts at around 600*C and decomposes at above 1000*C according to MSDSs. Not sure what it decomposes to. It is said to eventually hydrolyze to orthophosphate, but I don't have any specifics on that. If possible I would also like to make half of it potassium rather than sodium, it forms a eutectic. I have yet to work out a way to do the efficiently.

I built a phosphorus "retort" out of a piece of 4130 thin wall steel tube welded closed on one end. It has a pipe thread attachment welded to the other end. I took a pipe cap and welded on a fitting that attaches to automotive brake line. I bent a piece of said brake line to about the right shape to bubble into water, it is ready to run AFAIK. All steel, it should hold up hot phosphorus vapor and such shouldn't it? It has a pretty large capacity, about 350 cc. I hope the propane torch will handle that. Always have acetylene as backup though.

Also I have a box of borax that needs to be made into B2O3, not sure the best way to do that. Maybe add nitric acid since sodium nitrate is so soluble and boric acid is not?

One final problem is the reducing agent. I don't really have access to fine aluminum. Carbon works, and since my setup should handle the temperature, maybe that would be best. I like the idea of using solder because it melts so low, but I'm not sure if it will work. And I'm not sure how to easily grind it into a fine powder. Cooling it and trying to make it form alpha tin would be nice, but the 5% antimony makes that hard to do. Maybe with dry ice...

[Edited on 19-7-2008 by 497]
Sauron
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In the course of my investigations into preparing PCl3 I was taking a little detour to P2O3 (P4O6) and ran into an interesting paper by Krafft and coworkers in Ber. 34 565 (1901).

According to Krafft, the trioxide, trisulphide and trichloride of phosphorus (P2)3, P2S3 and PCl3) can all be reduced by metallic As or Sb to red P and the corresponding compounds of As or Sb.

P2O3 is far from readily available, but P2S3 is not. It is used in the match industry. PCl3 is hard to come by and hard to prepare but PBr3 is commercially available. Antimony metal is not hard to come by. So the reaction of P2S3 or PCl3 with Sb per Krafft may be of preparative value.

A while ago I posted the Brauer prep of vermillion P from PBr3 and Hg. That one produces an impure red P containing varying amounts of H6 bromides difficult to completely remove.

And recently in another thread I posted Michaelis' prep of red P from H3PO3 and PCl3 which I believe can be extended to PBr3. Ann., 325, 365 (1902). The product is 93% red P balance Cl.

I just wanted to call these reactions to your attention.

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