Sciencemadness Discussion Board

Red P (higher yeild method)

Slimz - 21-9-2007 at 16:13

ok so im sure you know you can get redP from matchbook covers.. thats SLOW and tedious.. here is a higher yeild method

This is just a SIMPLIFIED version of the method and does not include SAFETY instructions (like dont add lye to hot hydrocloric acid)

ok start with a carton of Coghlan's brand (yes that specific brand)
waterproof camping matches (buy an most camp stores where all the Coghlan's camp crap is)
This brand has redP caked on like crazy...

a carton is like 20 boxes of wooden matches

seperate the matches from the boxes (duh)

the boxes are wood and paper, break the box up so you only have the sides with the redP on it (this is glued to the paper)

soak in acetone untill the wood seperated from the redP/paper.

boil in Hydrochloric acid (i used muratic acid from HW store) untill the acid eats the paper (fumes bad)

dilute the acid once cooled

basify solution so you can filter it safely (i use lye)

filter soludion thru coffe filter (or whatever)

soak in acitone again (to clean it up and remove any leftovers)

filter again and there you have it, a bunch of RedP

[Edited on 21-9-2007 by Slimz]

Sauron - 21-9-2007 at 17:02

And how much red P is the take from a 20-box carton (40 box sides, I assume there is a srriler on each side of a box)?

The procedure in Rhodium talks about, like, 12 g from thousands of box striker strips.

So even if your brand has say 5X the RP on the striker strips, compared to the usual generic wooden safety matches, your carton will give up...milligrams.

Surely you can find a tweaker forum somewhere to post this?

Do you own shares in Colglan's by any chance?

Furthermore your procedure is ass-backwards.

You dump the strikers in acetone and stir. The acetone dissolves the adhesive that binds the P to the strips, it is easy to follow the progress. Filter the strips off from the slurry of red P in acetone using a Buchner funnel with no paper. Rinse the strips with more acetone.

Now filter the acetone through a fine sintered-glass funnel with suction. Now you have red P and some crud. NOW you do hot acid treatment to dissolve crud.

It is not necessary to cook the strips in hot acid as you suggest. Nor to neutralize the acid if you use a sintered glass funnel.

[Edited on 22-9-2007 by Sauron]

DerAlte - 21-9-2007 at 20:44

Yawn - why do you even bother, Sauron?

[Edited on 22-9-2007 by DerAlte]

Sauron - 21-9-2007 at 21:17

It's a slow morning here.

And I rather wish the matchbook thing were more practical, as I would like some red P. But it isn't.

The only method I know of that makes sense is the Hg redn of PBr3. This gets one about 100 g Red P for every Kg PBr 3 used, along with a lot of mercurous and mercuric bromide from which the Hg can be recovered. The red P is always a little contaminated with bromine, but that's okay as I am going to chlorinate it anyway.

How many matchbook strikers would have to die for 100 g red P? A LOT. PBr3 I can buy anytime. See the Brauer book, on bright red phosphorus (vermillion phosphorus).

Adun-Swim - 21-9-2007 at 22:10

FYI, each 1.00 box of matchbooks, with 50 striker pads apiece will net about 250 mg of RP. So, 4.00 per gram, and a whole f*ckload of wasted time and effort. Just thought I'd clarify, having tried it at one point myself.

Sauron - 21-9-2007 at 22:21

So 25 matchboxes per carton, 2 striker strips per each =50 striker strips. 250 mg so 5 mg per striker strip.

100 g red P = 10,000 match boxes (400 cartons)

Yes very tedious to do this way.

Slimz - 22-9-2007 at 09:03

go look at the matchboxes before you pop off at me...

Sauron - 22-9-2007 at 09:41

First of all that brand is not sold in this country, it is actually very poorly distributed internationally outside of the British Commonwealth.

Secondly, it was, is and always will be tweaker bullshit. If that brand has 5X as much red P on the strikers as another typical brand, you have an improved tweaker bullshit, but, still. And I doubt that the difference is that great. And anyway probably offset by much higher price than the Chinese made matchbooks sold here.

No sale, kiddo.

YT2095 - 22-9-2007 at 09:57

what you have to remember also, it that it contains ground glass!
so not all of the yield will be pure RP.

secondly it really all depends on what you want to DO with the stuff?

I have a 100g container of pure RP here, and over a Year I`ve probably only Used a gram (if that), so a little does go a long way!

this 100g is more than plenty to last a few lifetimes for general chem experimentation, so I guess if you Can`t buy it anywhere then obtaining your own isn`t so much of a big deal but maybe even worth it if your going to use and learn from it :)

woelen - 22-9-2007 at 10:15

@Sauron: You can buy PBr3, and no red P? This sounds very peculiar to me. Over here, red P can be purchased easily with some searching/effort, but stuff like PBr3, PCl3, PCl5 and POCl3 I certainly can't find as a home chemist. Red P is easy to handle and can be stored in a normal bottle, the phosphorus (oxy)halogenides are very corrosive, very easily hydrolyses compounds, isn't it? I have no personal experience with them.

I agree that the matchbox method of obtaining red P does not sound very useful to me. ANd YT2095 also is right, the red P usually is mixed with fine sand in order to make it more abrasive. Otherwise it would be harder to light matches by simply striking it along the matchbox cover.

Sauron - 22-9-2007 at 10:27

@woelen, peculiar sounding or not, these are the facts.

I can easily buy PBr3 and have done so, I have a Kg on hand.

I cannot buy red P, PCl3, POCl3, PCl5 without a special import license from the MOD, which is unlikely to be issued.

I can buy P2S5 and have done. I can buy POBr3 and PI3 if I wish but have not done so.

That's simply the way the regulations are written here. It is not logical but I am not going to point that out to the regulators.

Swany - 22-9-2007 at 10:36

I worked with PBr3 this previous summer, the first reaction I did in that lab was a fairly large scale -OH to -Br sub, using POBr3 generated in situo with PBr3 and Br2 (to make PBr5, presumably) and then that solid mass that formed had to be powdered with a spatula under N2 flow, this is difficult to do with a spatula when the mush is in a 3-neck flask and there is lots of it. Then it had to be mixed with P2O5, I think I remember this being nasty and my gloves were becoming blackened and my fingers were warming up. Time to double-glove. Such a shitty reaction. Reduced costs of product production from $7/g to $1/g though. POBr3 is expensive, the former 3 are not.

But, they were nasty to work with, IMHO. The whole, PBr3 reacting violently with water and P2O5 being, well, P2O5.... throw in a free halogen. Yum. Purifying was a bitch too: column chromotography, fairly large scale.

Point being, reducing a kilo of PBr3 does not sound like fun, but I am willing to bet the mercury reduction would be fascinating to see.

How much does POBr3 cost you as opposed to P2O5, PBr3 and Br2? Just curious.

Sauron - 22-9-2007 at 10:56

The last time I got a quote on POBr3 it was a lot costlier than PBr3. That agrees with your own observations.

But I have no particular use for POBr3.

PBr3 alone is very efficient at converting alcohols to alkyl bromides. But not as efficient as TCT/DMF with NaBr or KBr. So I am at a loss as to why you weremaking PBr5 in situ. PBr5 will brominate a hydroxyl and itself be oxidized to POBr3.

But anyway I suppose you had your reasons. Was it a phenoilic OH perhaps?

See Brauser's procedure for Hg redn of PBr3. This needs to be done in a sealed tube or an autoclave with heating and shaking (or stirring, it's not a vodka martini.) It takes a couple of days including the purification.

Swany - 22-9-2007 at 16:44

Two phenolic -OH groups, infact. The reaction has the nickname 'the smoke bomb' due to its first attempt producing very large amounts of HBr when it hit a certain temp. The said HBr did not have anything to bubble through, and I believe there were other complications as well. Either way, the fume hood had a certain rustic look to it afterwords.

How bad exactly is PBr3's reaction with water? I was not keen to handle it, as it fumed readily in air. Hydrolysis products would be HBr and some sort of oxyphosphorus acid, presumably? Something like that?

chemkid - 22-9-2007 at 17:24

Some of us have lots of extra match boxes therfore i wouldn't need to buy them. Thus this method isn't such bullshit if you consume lots of matched and don't feel like being listed for buying red phosphorus.


[Edited on 22-9-2007 by chemkid]

Sauron - 22-9-2007 at 20:04

PBr3 like PCl3 reacts vigorously (violently) with water to produce phosphorous acid and HBr. In the process the P atom goes from P(III) to P(V) so that the structure of phosphorous acid is


rather than P(OH)3

The anhydride of this acid is the horribly toxic P2O3.

Phosphorous acid is commercially available.

P2O3 AFAIK is not. It can only be prepared by the burning of WP in a limited supply of oxygen. As WP is essentially unavailable (worse than RP) this is preparatively useless.

The usual lab scale prep of phosphorous acid is to moderate the reaction of PCl3 and water by adding conc HCl. However, since H3PO3 is available and PCl3 is much less available this is also a non-starter. The acid is also a lot cheaper than PBr3 so that is not very practicable as alternative.

A pet theory of mine is that a very strong and dehydrating chlorination reagent would possibly convert H3PO3 to PCl3. The reagent of choice would be oxalyl chloride. A large excess would be needed so this would be an expensive method if it works, and an expensive failure if it does not. We know that oxalyl chloride converts As2O3 to AsCl33 for example. P2O5 to POCl3 by this reagent is very likely. One of these days I will try this one out. However I found a cheaper easier way to make POCl3. But that one I will keep to myself.

MagicJigPipe - 23-9-2007 at 00:04

Keep to yourself huh? You are such a great guy, Captain. In the US it is very difficult to obtain Red P and even more difficult to obtain PBr3 or PCl3 because of them being "hazardous materials". And if one does purchase Red P in any quantity over 100g or so they will almost certainly be checked out by law enforcement since it is in the DEA's List I precursors. I can see where the matchbook process might be the way to go in a few instances.

In fact, I might attempt to do this in order to obtain the phosphorus I need for PCl3, PBr3 and PI3.

But I have no use for these substances at this point in time.

Call me what you will but if you can tell me an easier way then I am all ears.

Sauron - 23-9-2007 at 00:14

The matchbook method is not an easy way; it is a time consuming nd laborious way to obtain anything but a miniscule quantity of red P.

Anyone who can buy 100 g or less without undue hassles, and who needs the stuff, should do so. You would probably attract more attention by buying 400 cartons of 25 matchbooks each to obtain the same material.

No LEGITIMATE user has anything to fear. Of course that lets out the drug cooks and the jihadis, doesn't it?

Adun-Swim - 24-9-2007 at 15:48

Well, it's not easy, and for 100g of RP, it costs $400. The ground glass isn't an issue, as you would use a solvent, not just scraping the fucking RP off.

JohnWW - 24-9-2007 at 16:57

I am fairly sure that there are at least some organic reactions for which either S (much cheaper) or Se could be used as a substitute for red P, as a reducing agent, although under modified reaction conditions. This would not be possible where, for example, S or Se could add across C=C double bonds. Other possible reducing agents which could conceivably be used for some of the same reactions, under modified conditions, could be CO, SO2, and sulfites. Graphite is too inert to be used as an organic reducing agent, at the required temperatures.

Sauron - 24-9-2007 at 20:20

I do realize that my own location and circumstances are not typical and perhaps I have more resources than most of us. But I can't buy red P, period full stop, without a special permit from the MOD, which is a nightmare to obtain.

On the other hand I can buy PBr3, and I have worked out a procedure to use this for my immediate purpose (phosphites prep) in lieu of PCl3 that I can't buy, or red or white P to chlorinate. So, my interest in PCl3 and red P is greatly diminished.

Things I can buy:

P2S5 (have lots)
PBr3, POBr3 - have a Kg of the tribromide
H3PO3 (phosphrous acid)

Things I can't buy w/out spl permit


However, I can make POCl3 if need be. I can think of at least two methods.

PCl3 and PCl5 are a lot harder to get to without red P (or white P) to start from.

And if I must I can reduce PBr3 with Hg and get red P that way.

Costly but WTF.

$400 worth of matchbook strikers is costly too, more so when you toss in the time and aggravation/labor.

Now, if I were someplace where I could not buy PBr3 maybe my choices would come down to:

1. Matchbooks
2. Moving to another project.

There are usually options, if you look hard enough for them.

My understanding is that in USA it is difficult but not impossible to buy smallish quantities of red P but that many amateur chemists shy away from doing so for a variety of reasons citing concerns over privacy, overenthusiastic law enforcement, potential EPA econazi hassles, etc. Fair enough, but at least those of us in USA have a personal choice to make. I have NO choice, I can't buy red P legally and I am clueless as to black market sources and very reluctant to contemplate less palatable options.

Anyway my main problem has now been alleviated, since PBr3, on hand, will do the job. And more can be had if I want to turn it into red P then PCl3/PCl5.

[Edited on 25-9-2007 by Sauron]

chloric1 - 25-9-2007 at 01:50

Given red phosphorus can be formed under certain conditions from a halide, it may be worthy to notw that some halides can be synthesized from phosphates/carbon in a stream of chlorine/bromine at 750 degrees C. These reactions yield primarily oxyhalides. Also, calcium phosphate can be reduced thermally to phosphide and this can be chlorinated. Carbon and lead phosphate is said to release phosphorus at red heat. No sense in risking a DEA invasion to buy red P.

Sauron - 25-9-2007 at 04:06

Yes the oxychloride can be made from phosphates at high temperatures requiring a tube furnace but I would hardly call having to deal with POCl3 at 750 C convenient, and few of us have a tube furnace. (though I admit to one.)

The chlorination of phosphides is purely speculative. And phosphides also only release P vapor (and that is white P vapor) at high temperatures. These might form practical industrial processes but for the home chemist they strike me as rather remote possibilities and hazardous. More hazardous than the DEA.

SsgtHAZMAT - 25-9-2007 at 04:11

Originally posted by Sauron
It's a slow morning here.


Sauron - 25-9-2007 at 05:09

Hey Sarge. Can you expand on WOW. It's a wee bit elliptical.

Slimz - 25-9-2007 at 06:42

elliptical - Of or relating to extreme economy of oral or written expression

For those of you who thought it was a gym machine.

oh.. wrong forum... :)

chloric1 - 25-9-2007 at 14:18

Originally posted by Sauron
Yes the oxychloride can be made from phosphates at high temperatures requiring a tube furnace but I would hardly call having to deal with POCl3 at 750 C convenient, and few of us have a tube furnace. (though I admit to one.)

The chlorination of phosphides is purely speculative. And phosphides also only release P vapor (and that is white P vapor) at high temperatures. These might form practical industrial processes but for the home chemist they strike me as rather remote possibilities and hazardous. More hazardous than the DEA.

Well actually Sauron I was refering to to chlorinating phophides in a chlorinated solvent. So no P vapor at all. Unfortunately, I have not tried this myself. PCl3 boils at 76C so methylene chloride which boils at 34C would suffice. Or, a high boiling solvent such as tetrachloroethane might work.

Sauron - 25-9-2007 at 17:23

True. However, if I recall from the threads concerning phosphide halogenation, this reaction, whether in gas phase or in a liquid medium, remains conjectural, i.e., no one has advanced any literature to support it.

Phosphides being toxic and pyrophoric thay are often hard to buy, hard to ship, hard to import. They are after all sources pf PH4 and diphosphine. I am not at all sure I can buy them.

Making the phosphides from phosphates is one of those tube furnace affairs.

So while I did not forget this ides or dismiss it out of hand I have back-burnered it while seeking safer and more practical alternatives.

If you have any lit., or your own experimental experience with this I' all ears and so are others I am sure.