Sciencemadness Discussion Board

POCL3-Phosphorus Oxychloride

ryan81 - 4-8-2015 at 17:03

Any custom apparatuses that one could recommend for the primary synth.

ryan81 - 4-8-2015 at 17:05

Why is this chemical so hard to create, I guess any chemical which reacts with 02 is.

careysub - 4-8-2015 at 17:21

Quote: Originally posted by ryan81  
Any custom apparatuses that one could recommend for the primary synth.


That question is discussed in this thread:
http://www.sciencemadness.org/talk/viewthread.php?tid=50249

ryan81 - 4-8-2015 at 17:28

Mr. Careysub,

I am very familiar with this, but cannot picture this part, nerveless re-create it. Can you advise. ). The reaction vessel is placed in an
air oven and connected to a bend leading through a Liebig condenser to a receiver flask
immersed in cold water. The outlet from the flask is vented through a CaCl2 protection
tube with a bubbler optionally attached for observation of reaction progress.
Diagram would be much appreciated

byko3y - 5-8-2015 at 02:54

Wiki has already described all the easy routes:
PCl5 + SO2 => POCl3 + SOCl2
PCl5 + RCOOH => POCl3 + RCOCl
3 PCl5 + 2 B(OH)3 → 3 POCl3 + B2O3 + 6 HCl
3 PCl3 + KClO3 → 3 POCl3 + KCl

softbeard - 6-8-2015 at 08:50

Quote: Originally posted by ryan81  
Why is this chemical so hard to create, I guess any chemical which reacts with 02 is.


POCl3 does not react with O2 and is not sensitive to it. POCl3 does react with H2O and is easily hydrolyzed by water vapor in the air. The reason POCl3 is air-sensitive is moisture, not oxygen.

chemrox - 6-8-2015 at 11:15

and hydrated POCl3 is known to detonate ;^)

zed - 6-8-2015 at 16:50

"Wiki has already described all the easy routes:
PCl5 + SO2 => POCl3 + SOCl2
PCl5 + RCOOH => POCl3 + RCOCl
3 PCl5 + 2 B(OH)3 → 3 POCl3 + B2O3 + 6 HCl
3 PCl3 + KClO3 → 3 POCl3 + KCl"

If you can acquire the above precursors, you can probably acquire POCl3 itself.

Wiki also mentions production via Phosphorus Pentoxide. Unlike the other mentioned reagents, Phosphorus Pentoxide is more or less, available. At any rate, its distribution is probably not as restricted as that of other precursors.

Aqua-regia - 7-8-2015 at 06:27

Other ways to get the stuff:

PCl3 + Cl2 ——> PCL5
3PCL5 + P2O5 ——> 5POCl3

just mix in right molar ratio, bubble in the mix chlorine till the solution will be constant yellow and distill


Ca3(PO4)2 + 4(NH)4H2PO4 ——> 3Ca(PO3)2 +6H2O + 4NH3
Ca(PO3)2 + 2C + 4Cl2 ——> 2POCl3 + CaCl2 + 2CO2

For this methode need electric tube furnace reactio goes 650 C degrees

reference: an old patent. I already tryed, its OK.

http://worldwide.espacenet.com/publicationDetails/originalDo...

byko3y - 7-8-2015 at 20:30

There's pretty much no way to the POCl3 directly except from phosphorus halides/oxides. Well, Aqua-regia actually described the only well-known phosgen mediated direct synthesis of POCl3, however, the actual reaction is more complex and the equiation only superficially describes the process:
Ca(PO3)2 => Ca3(PO4)2 + P2O5
P2O5 + C => P2O3 + CO
CO + Cl2 => COCl2
P2O5 + COCl2 => POCl3 + CO2
P2O3 + Cl2 => something
and so on.

chemrox - 18-9-2015 at 16:36

All glass ware must be clean and dry. The round bottom distilling flask containing 21 g of finely powdered potassium chlorate is connected with a condenser and receiver. From the dropping funnel slowly 69 g of phosphorus trichloride are added into the flask a little at a time. After each addition of small amount of phosphorus trichloride, reaction takes place by a gentle ebullition. If reaction is slow slight warm may be applied. When the reaction is complete, phosphorus oxychloride is distilled. Further purification is performed by re-distillation and collecting fraction boiling at 110° C.

Laboratory methods of inorganic chemistry by H. Biltz, 77h, 1928