Sciencemadness Discussion Board

P2O5 solvent

Microtek - 20-2-2003 at 01:38

Just a quick question:
I'm looking for a nice inert solvent for P2O5 to eliminate some of the problems arising when working with this material. Specifically, the solvent must be inert with respect to fuming HNO3 ( and preferably miscible with it ) as the P2O5 is needed for demanding nitrations such as
RRN-Ac --> RRN-NO2
Any help would be appreciated.

Edit: Corrections to the reaction.

[Edited on 20-2-2003 by Microtek]

Polverone - 20-2-2003 at 09:06

Hmm, I see that H2SO4 is listed as a solvent for it in Lange's Handbook, and it would certainly be inert to nitric acid too. But do you need a sulfuric acid free mixture?

rikkitikkitavi - 20-2-2003 at 09:20

Oh, but P2O5 will react with H2SO4 and create SO3 and phosphoric acid. But I m sure this will be a equlibrium reaction, hard to tell actual equlibrium composition though.


Perhaps a non-oxygen contaning solvent like MeCl2?

/rickard

Polverone - 20-2-2003 at 09:56

Ah, drat. But wouldn't MeCl2 be vulnerable to oxidation? Maybe CCl4 would do the trick.

Microtek - 21-2-2003 at 09:42

In that patent Xoo posted, they used chloroform as their preferred embodiment. I'm pretty sure CH2Cl2 would work as well ( at least it doesn't react with the nitric; there's a method for extracting 100% HNO3 from H2SO4/HNO3 mixes. )

DDTea - 25-2-2003 at 19:05

A bit off topic- Could I ask you where you got P2O5? It's a very useful chemical, and I would really like to have some.

Microtek - 26-2-2003 at 04:10

From a lab supply. I function as a freelance researcher for a small business so I can get most chemicals except those labeled as poisonous, as they require permits. It's very expensive though, so I try to make do with OTC chems.
BTW, I have tested nitromethane, and it seems to form a colloidal suspension of P2O5 without reacting with it. It also seems quite inert to HNO3.

roamingnome - 30-9-2006 at 14:44

super phosphate fertilizer says P2O5 on the back
white granuals


for some reason this isnt the stuff i think its is?

Mr. Wizard - 30-9-2006 at 15:20

Quote:
Originally posted by roamingnome
super phosphate fertilizer says P2O5 on the back
white granuals


for some reason this isnt the stuff i think its is?


You are right to doubt. It lists what the fertilizer's equivalent is for P2O5, so you can compare it's strength to another brand or compound. I doubt it would EVER contain free P2O5.