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Magpie
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Do you have an idea of how high a temperature you are going to have to heat this? I'm presuming it will have to form a melt before you can expect any
significant reaction.
The single most important condition for a successful synthesis is good mixing - Nicodem
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jimmyboy
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something pretty powerful will be needed - hot enough to melt steel - ive seen four possibilities so far - thermite reaction - acetylene - gas/blower
furnace - and the carbon arc
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Agamemnon82
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oxy-acetylene torch, plenty hot enough to melt steel  I'm going to be using a
ceramic reaction vessel and tubing leading into water. Still a couple of weeks untill i'll be ready.
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Magpie
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I'm in no way trying to discourage you testing this route but if you need that kind of temperature (1600-1700C) why not use the standard industrial
mix:
(Ca)3(PO4)2 + SiO2 + C ---> P + etc ?
Is there some particular advantage to using the reactants you have chosen?
The single most important condition for a successful synthesis is good mixing - Nicodem
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Cyrus
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Well, if all we need is 1340 degrees C, to melt the NaPO3, that's not too hard to get.
That is quite refractory for a sodium compound... but 1340 deg. C is 2444 degrees F, and I know for a fact that one can get to that temperature easily
w/ 3" of kaowool insulation and a waste oil burner. A venturi propane burner will also get that hot. There's simply no need for exotic arc furnaces,
however sweet they may be.
(How do I know? I was firing some ceramics to cone 10 (about 2381 degrees F, but it depends on how fast you heat the kiln) and the cone, which is
supposed to bend over at 2381 degrees, had turned into a puddle by the time I was done with it. )
High temperatures are pretty easy to reach with kaowool. Mine was only rated to 2300 degrees, so I would recommend 3" of 2300 kaowool and perhaps an
inch of 2800 degree F castable refractory on the inside to build a furnace. Heat with a Reil EZ burner using propane. If you're careful, the whole
thing should cost less than $100, and it will be a sweet furnace.
Cy
PS- what I'm worried about is what you're going to use to contain the mix. Clay w/ a lot of alumina? Sintered alumina? These are pretty porous, so
gasses will escape. Perhaps a high alumina layer to resist evil fluxing action by the sodium, surrounded by a glassy porcelain layer, which will seal
in gasses. Quartz ? 
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Rabidwolf
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hmmm,
how hot would a meeker burner running off a 20pounder(BBQ size) tank of propane get?
mebbie adding a shiteload of insulation around a stainless steel pipe stub that's aboot 3in dia and 6in tall, capped at one end and a 4in-to-1/2in
reducer going to some stainless steel tubing that's led under water would work...
ah.....the wonderful thing about TIG, is that TIG is such a clean and precise thing
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Gruson
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Hello there. For a school project in Holland I chose to do some research on the preparation of White Phosphorous. There was some practical stuff, too.
 A couple of weeks ago I prepared white Phosphorous from the following reaction:
12NaPO3 + 20Al + 6SiO2 = 6Na2SiO3 + 10Al2O3 + 3P4
The products reacting were 40 grams in total. NaPO3 was obtained from heating NaNH4HPO4. The remaining glassy stuff was crushed (damn hard it was) and
dried in a drier at 80°C. SiO2 were not especially small particles, just made it with HCl and NaSiO3. Al was 100 um.
The reaction vessel looks a lot like BromicAcids's second one. But where he goes for a 'gass ball valve' (or something like that) I used a
overpressure of nitrogen of 1.1-1.2 bar.
The reaction vessel is 20 cm long, throughcut 5cm. The steel is 5mm thick. A small pipe for the nitrogenflow is welded on the reaction vessel. That
pipe is 6mm through, and 10 cm long. The bottom of the reaction vessel is welded airtight. (It's just closed, don't know how tot say that in english.)
The drainpipe for the gasses and P4 was screwed on the top of the reaction vessel. The drain is 20mm through. It is has a 90° bow. From the end of
the vessel to the bow is the drain 15 cm, after that 40 cm long. Less heat was transferred to the water then we expected.
Picture of it in use (quite big, sorry for that)
I used a acetlylene burner for the heating. It melted the outside of the reaction vessel, so you had tot be careful not to burn a hole in your
reaction vessel.
Closeup:
We put the end of the drain under boiled destilled water. In patent 2,050,796 it stated that dissolved oxygen in the water would oxidise the P4, so I
boiled it and put in a PE bottle for usage.
The drainpipe while P4 came over, P2O5 'smoke' is formed.
The vessel was first heated 15 mins to 400°C to get rid of the H2O which would form PH3/P2H4. (Comprehensive Treatise on Inorganic and Theoretical
Chemistry, vol 8) We also added some carbon (tip from Gmelins' to prevent phosfine forming)
After we heated it for about 2 hours the P4 started to came over. The water was becoming a bit whitey, what was supposed to be colloidal white P.
After a while some solids were formed on the bottom. The heat was turned off after 3 1/2 hour.
This pic is after the reaction, it shows the white P on the bottom, seen from above.
If you stirred it up some P2O5 smoke was formed above the surface.
A day after the reaction I performed the 'Mitscherlich test' to positively identify white P. Is shows some greenish lighting, and that proofs the
whitey-yellow stuff is white/yellow phosphorous.
Some of the solution was shaken with some CS2, and then placed under an UV lightsource. After a day or so, it started to look a bit reddish. Red P was
formed.
This picture is after a week. Red P is like a film layer on the CS2. The upper layer is water.
Well, to conclude: I managed to make White P out of the NaPO3/Al/SiO2 method, relatively easy. If you can get hold of a acetylene torch, there should
be no problem at all. You don't have to insulate your reaction vessel, seems to me. If you are using another heating source, you probably should.
Mainly with the help of this thread, and the use of some old standardworks this project came to an good end. Thanks for every bit of information
posted here, maybe you can get something usefull out this post. If something is not clear, just ask. Thanks!
It could be that the purpose of your life is only to serve as a warning to others.
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Magpie
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Nice work Gruson.
I have a question about the nitrogen purge. My understanding is that this is a continuous flow at a regulator pressure of 0.1 - 0.2 bar above
atmospheric pressure. Is this correct?
You are fortunate that your school would let you tackle such a project. Somehow I can't envision that happening in the US. I'm sure you learned
quite a bit.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Gruson
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Thanks
Yes, that's correct. The nitrogen flow was ideal for the P4 not being oxidized (much cheaper then welding argon), and it also prevented, when the
reaction was done and the vessel was cooling down, suckback of water what may have lead to a possible steam explosion. (although the drain had a not
so small diameter and was quite long.) The N2 bubbles came out of the drain at a rate of 1 per 2 seconds or so. IIRC we used 15-20 bar of nitrogen
during the experiment.
Indeed, I was quite lucky to do such a project at school. I had to talk quite a lot to get permission though.. But after exstensive research I
succeeded to talk over my teacher. (he liked the idea a lot, it only had to be done 'safely'). I had quite a lot of fun with this project, and indeed,
I learned a lot. Safety measures, technical solutions to problems, researching, etc, etc.
It could be that the purpose of your life is only to serve as a warning to others.
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jimmyboy
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very nice work - dang -- 3 hours of acetylene/o2? how many tanks of gas did you go through? and what was the yield?
thats what - a 300 dollar investment for some phosphorus - but grats on the success - nice pics as well
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Rabidwolf
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| Quote: | Originally posted by Gruson
Thanks
Yes, that's correct. The nitrogen flow was ideal for the P4 not being oxidized (much cheaper then welding argon), and it also prevented, when the
reaction was done and the vessel was cooling down, suckback of water what may have lead to a possible steam explosion. (although the drain had a not
so small diameter and was quite long.) The N2 bubbles came out of the drain at a rate of 1 per 2 seconds or so. IIRC we used 15-20 bar of nitrogen
during the experiment.
Indeed, I was quite lucky to do such a project at school. I had to talk quite a lot to get permission though.. But after exstensive research I
succeeded to talk over my teacher. (he liked the idea a lot, it only had to be done 'safely'). I had quite a lot of fun with this project, and indeed,
I learned a lot. Safety measures, technical solutions to problems, researching, etc, etc. |
kudos scientific brotha'
what kinda mark did you end up getting on your project?
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Gruson
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Well, we performed the project in a smithy (construction company) and they had pillars where you could plug your C2H2/O2 connection in. So I don't
know exactly how much was used, but I can imagine it was quite a lot.. About the costs: That's the good thing when doing this kinds of project for
school: School pays everything.. Although that was not that much, the men at the workshop were extremely kind and just asked some crates of beer, and
that was all..
The maximum yield of a reaction mixture of 40 grams was 8 grams White Phosphorous. We were able to isolate some 5 grams of white P (measured under
water, volume is x ml, should weigh x grams but weighs x+y grams, so y could be white P), and also 1.6 grams of Red P (from whiteP+UV -> RedP)
So the yield was.. 82,5%,  Or should be somewhere around that number.
My mark.. 7.3 out of 10 (7 for practical part, 7 for presentation, 8 for theory & research). Not all that high, but hey, the highest mark was a
7.6 and that was for a lot less spectacular experiment about polarisation.. But I'm happy with my little project that succeeded against all odds, and
I'm also happy that I'm still alive and kicking.
It could be that the purpose of your life is only to serve as a warning to others.
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Magpie
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Working for "crates of beer." This sounds like a simpler and better time in the US.
I'm very happy to see that your school has not succumbed to the "grade inflation" that is so rampant in the US. I do, however, think that you should
have been given at least a "9" for project management and perseverance.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Madandcrazy
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Can phosphorus not isolated by a isomer of phosphoric acid (hydrolysis) to the oxide ?
Maybe natrium dihydrogenphosphat form per elctrolysis some dilute (HPO3)n and takes up phosphorus to a elektrode.
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Gruson
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In the scan of BromicAcid Gmelin's its stated that molten NaPO3 can be electrolyzed with a Ni kathode. Just that. NaPO3 can be obtained quite easily
from heating NH4NaHPO4. Maybe sodiumdihydrogenphosphat will do it as well. Didn't do much research on the elektrolysis path, heating seemed easier to
me..
It could be that the purpose of your life is only to serve as a warning to others.
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jimwig
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pardon if this has been cited ;;;
Method of Preparing Phosphorus
US6207024
http://v3.espacenet.com/results?sf=n&FIRST=1&F=0&...
Abstract - A method of producing phosphorus in which a mixture of phosphoric acid and carbon reductant is exposed to microwaves at a power level
sufficient to heat the mixture to a temperature at which phosphorous is produced. This method can be carried out at lower temperatures than
conventional phosphorous production and does not give rise to the solid waste normally formed in conventional phosphorous production. The phosphorus
thus formed can be converted back to phosphoric acid, thus effecting purification of the phosphoric acid.
__this lower temp referal seems to get around the stumbling block of non lab type prep apparatus.
__also excepting the inert atmosphere (possibly avoidable) this seems to posses workable attributes
__the refs contained within the text are IMHO great.
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Mason_Grand_ANNdrews
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I`ve read Phosphorus exists in three different isomers.
Phosphorus red
Phosphorus white
Phosphorus black
I belive, all isomers can isolated by a other of the isomers. I found two methods obtaining Phosphorus red by Phosphorus white.
Careful put some quickly dryed Phosphorus white in a test tube and close this with a cotton-wool. The Phosphorus is heated itself and reacts with the
oxygen in the test tube. Some fumes of Phosphorus red is deposited on the side of the test tube and the reaction is finished. Convert the rest of the
Phosphorus white to red, the test tube is heated to 270 - 275 gegree celsius until the converting is ending.
I guessing the better way is converting Phosphorus white to Phosphorus red at lower temperatures when the white P is added to a mixture of carbon
disulphide/iodine in a ratio of 95/5 and this is careful heated with a burner.
Thats quite easy but i assume the special interest of the treath is obtaining white P by red P. Perhaps, i found a simple method later.
Do someone have any more information to black P ?
[Edited on 19-6-2006 by Mason_Grand_ANNdrews]
[Edited on 19-6-2006 by Mason_Grand_ANNdrews]
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Gruson
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Carefully heating CS2 with a burner? You rather then me..
Red P is made by putting white P in pipes, closing them and heating for 50 hours at 240-250 °C. Reaction product is treated with CS2, to remove
unreacted white P.
This is not a method you choose to do at home, especially when there is a much easier way to make red P out of White P.
(as mentioned somewhere in the thread)
If you have CS2, dissolve white P in it. Place it in the sun / under an UV lamp. White P reacts under UV radiation to Red P, which will precipitate
out of the CS2. (After a couple of days the reaction is complete, recording to my experiments [no change was observed after 4 days])
If you don't have CS2, just put the white P in a airtight container, and place it in the sun / under an UV lamp. White P will convert to Red P (the
smaller the size of your White P, the faster).
I suggest you read some literature on this subject, all the answers you seek are in it.
Well, on black P.. (in Comprehensive Treatise on Inorganic and Theoretical Chemistry, vol 8 it is called violet / metallic P)
| Quote: |
W. Hittorf prepared metallic or violet phosphorus by heating phosphorus
in contact with lead for I0 hrs. at a temp. near 500 °. The phosphorus dissolves in
the lead at the high temp., and on cooling separates from the lead in the form of
small, dark, reddish-violet, rhombohedral crystals. The crystals can be separated
from the lead by treatment with dil. nitric acid, which dissolves only the lead.
The crystals are further purified by boiling them with hydrochloric acid. A. Stock
and F. Gomolka recommended the following procedure :
W. Hittorf's phosphdrus is best prepared by heating 3 grms. of pure phosphorus wRh
200 grins, of lead in a sealed hard glass tube, packed in sand, to 800 ° for 48 hrs. The
glass is broken and removed in a freezing mixture, and the lead cleaned by [,rushing
by washing with hydrofluoric acid. As nitric acid attacks the phosphorus, the lead is best
removed by electrolysis in acetic acid containing lead. The cathode is placed at the bottom
of the vessel, a clock-glass being fixed below the rod. The residue thus obtained contains
some lead, mechanically dislodged from the anode, and is purified by boiling with hydro-
chloric acid in an arm. of carbon dioxide, followed by treatment with hydrofluoric acid.
The purest product still co.ntains 1.5 per cent. of lead.
[Comprehensive Treatise on Inorganic and Theoretical Chemistry, vol 8, pg. 747]
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Black P has about the same structure as graphite, hexagonal plates. It conducts electricity.
It is the hardest to make allotrope of P for a amateur scientist..
It could be that the purpose of your life is only to serve as a warning to others.
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Mason_Grand_ANNdrews
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White P is obtained by quickly cooling the vapours of red P, but it shouldn't ignite with the oxygen in the air. Can white P safe stored in H2O, in
airtight and lightproof flasks always. Some nasty green highly toxic substances will form with the H2O on the surfaces of the white P.
Also, i guessing it will walk when the converted vapours of the white P are quickly and cool transfered to the storing liquid and less oxygen is
present.
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Rabidwolf
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| Quote: | Originally posted by jimwig
pardon if this has been cited ;;;
Method of Preparing Phosphorus
US6207024
http://v3.espacenet.com/results?sf=n&FIRST=1&F=0&...
Abstract - A method of producing phosphorus in which a mixture of phosphoric acid and carbon reductant is exposed to microwaves at a power level
sufficient to heat the mixture to a temperature at which phosphorous is produced. This method can be carried out at lower temperatures than
conventional phosphorous production and does not give rise to the solid waste normally formed in conventional phosphorous production. The phosphorus
thus formed can be converted back to phosphoric acid, thus effecting purification of the phosphoric acid.
__this lower temp referal seems to get around the stumbling block of non lab type prep apparatus.
__also excepting the inert atmosphere (possibly avoidable) this seems to posses workable attributes
__the refs contained within the text are IMHO great. |
hmmmm, this seems like an intresting microwave expariment....
and my friend has 2 microwaves for exparimental purposes
that he also wants to get rid of....
so i'm theorizing ground up charcoal mixed with hydroponic store grade phosphoric acid in a glass dish.
put in a microwave,
in the middle of the yard,
powered by an extension cord.
would both confirm this patent,
and provide an entertaining show of white phosphourus Vs. a household microwave
(via the white phosphourus being allowed to form in an "open pot" type rxn in the sacrificial microwave)
thoughts anyone?
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not_important
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Still have to get it up above 500 C, which may be difficult in a home microwave without susceptors to absorb enough energy and insulation to keep the
loses down.
Here is a discussion on using a microwave for metals casting. While they are going up to the 800 to 1000 C range, there are some general guidlines
there.
http://home.c2i.net/metaphor/mvpage.html
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jimmyboy
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i was thinking maybe if you had the pipe insulated or placed inside an improvised kiln - alot of acetylene would have been saved (alot of heat saved)
- or maybe a small tank of propane could have been used instead .. since its been done maybe some tweaking could be had
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Sauron
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The cleanest form of the reductive preparation of WP is carbon (graphite powder) and P4O10 which gives only P4 vapor and CO. You still need red and
white heat though. And superheated phosphorus vapor IS a hugely hazardous affair, don't kid yourself.
Red phosphrus when heated always recondenses in the white form. That is, P4 vapor is white phosphorus. You convert WP to the red form by pressure and
seperate the two by taking advantage of the difference in solubility in CS2. White dissolves in CS2, red does not. Red is relatively nontoxic but the
caveat is that is must be totally free of the carcinogenic and otherwise toxic white form to achieve that state of grace.
My tube furnace only goes to 1100C to if I need red P I recover it tediously from match boxes. I don't mess with white at all. Moatly I don't need
elemental phosphrus for anything as I can easily buy PBr3 PBr5 POBr3 and PI3 and I know how to make my own POCl3 from P4O10. The hassle is PCl3 for
which red P is needed to make.
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Sauron
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I have some legitimate uses for trialkyl phospites but the lower ones at least are verboten per CWC. Therefore I look to prepare my own, which means
PCl3 also verboten. PBr3 however is not restricted at least where I am. I have succeeded in buying this from Merck. The question mark is this: it is
clear from the lit. that the reaction between alcohols and PCl3 depends on efficient stirring and efficient scavenging of the hydrogen chloride
produced in order to minimize the cleavage of the P-ester formed to hydrogen. That is the formation of dialkyl hydrogen phospite instead of trialkyl
phospite. See the Org.Syn. prep of tri-isopropyl phosphite, authored by chemists who worked with B.C>Saunders at Porton Down.
My point is that this side reaction is supposed to be worse with PBr3 and much worse with PI3. Which is why PCl3 is the preferred reagent and perhaps
why PBr3 and PI3 were not proscribed by CWC (or even the Aust.Grp.) Do any of you have references or experience regarding this issue?
So where does that leave one? Back to the problem of obtaining elemental P. I am not attracted as a matter of aesthetics to tearing up 100,000
matchbook boxes to laboriously recover 50-100 g of red P. But I can't buy it here without a permit from the MOD permanent secretary. Not impossible I
am told, but onerous.
I noted with interest in Brauer's book a prep of "bright red P" from PBr3 and Hg. Anyone ever try this? It looks laborious but at least these are
chemical labors and not tearing up matchboxes.
As an alternative I think one might purchase higher alkyl phospites that are unrestricted (say in the C4-C8 range) and cleave them back to PCl3 with
chlorine or appropriate chlorinating reagent (classically PCl5 but if I had that I'd have PCl3.)
As to the prep of PCl3 I dount that direct chlorination of red P "always" produces only PCl5. PCl3 has to be formed first. The member must have been
running in Cl2 too rapidly. The procedure described in Merck calls for a SLOW stream of chlorine. The inorg reference books indicate cooling is
advised, which contradicts Merck's recommendation of warming the red P in absence of air prior to introduction of the chlorine. Anyway the PCl3 formed
will contain some PCl5 but that can be left behind by distillation. And yes absolutely, PCl5 admixed with red P will disproportionate slowly to PCl3.
If you heat PCl5 enough it disproportionates to PCl3 and Cl2 but this isn't very useful preparatively because they will just recombine. Maybe under
reduced pressure one could seperate them in cold traps efficiently.
It might be advantageous to suspent red P in a solvent in which Cl2 is highly soluble and control the rate of reaction that way, dissipating heat of
reaction by reflux. Run in the chloring slowly, the red P will react and disappear, and only then will PCl5 start to form assuming efficient stirring.
Pick a solvent (hopefully) in which PCl5 is soluble but PCl5 is not and in that case, stop adding Cl2 as soon as PCl5 starts to fall out of the rxn
mixture. Seperate the PCl3 from the medium and purify. Seems more controllable than reacting a solid with a gas to make a liquid anyway.
Comments?
[Edited on 25-12-2006 by Sauron]
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Sauron
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By the way my application for trimethyl or triethyl phosphite is the prepn of BEDT-TTF. The final coupling to the tetrathiafulvalene system employs
TMP per Org.Syn. Supposed to be really nice dark red crystals, which are charge transfer complexes -- all those conjugated nonbonded electron pairs on
the 8 S atoms in the two pairs of rings. The materials-science lads have determined that certain complexes of this system are "organic
superconductors" at relatively high temperature, and thus they are theoretically and technologically of great interest.
The other route to this system calls for reducing CS2 with a large quantity of sodium shavings (as usual potassium works better but sometimes blow up
instead.) The notion of scraping sodium ingots over a cheese grater over a pool of pet.ether just does not float my boat. Although getting that
polycyclic to form that way is very neat.
The better IMO route is to start by reacting ethanedithiol amd chloroacetyl chloride. This is straightforward enough. Ethanedithiol can be purchased.
It reeks and gives one a nasty headache so a good hood is advised. Chloroacetyl chloride where I am, is a bit of a bother as only one company (Merck)
has an import license for it and Merck advises it would have to be shipped by ocean in a refrigerated container, so sorry. Therefore, I will have to
make my own from the readily available chloroacetic acid. Not a big deal though it is unplesant stuff to work with. The next step is chlorination with
N-chlorosuccinimide in CCl4. Must find an alt. solvent (maybe DCM) or make my own CCl4. Lovely. Then a neat rex with a xanthate amd a cyclization.
It's really a very elegant procedure well worth one's attention. The final step is the phosphite-mediated coupling.
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