woelen
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Failed attempt at making NO2Cl
From literature I understood that NO2Cl gas can be conveniently made by adding chlorosulfonic acid to fuming nitric acid. The reaction is said to be
smooth and complete:
HNO3 + SO2Cl(OH) --> NO2Cl + SO2(OH)2
The NO2Cl escapes as bubbles of colorless gas.
For this experiment I made a small quantity of yellow fuming nitric acid, using a microdistillation setup with 25 ml flasks. The resulting nitric acid
has a yellow/orange color and fumes heavily in contact with air.
I put 1 ml of this acid in a miniature test tube, using a pipette.
Next, I intended to add 1 ml of chlorosulfonic acid. I made a setup to drip the chlorosulfonic acid into the nitric acid from a pipette, but I quit
the experiment after the first drop. When the first drop hits the nitric acid, then a loud crackling noise is produced and half of the liquid is
ejected from the test tube  No droplets could be found on my workbench, there
was just a big puff of white fume.
I think that my fuming nitric acid is not strong enough, it most likely still contains quite some water (maybe 10%) and this leads to an EXTREMELY
violent reaction with the chlorosulfonic acid. This experiment is not safe and I quit the entire idea of making NO2Cl in this way. Chlorosulfonic acid
and water is a very bad combination. The reaction between the two is insanely violent.
Do others have experience with this reaction? I want to make some NO2Cl, suck up this gas in a syringe and do some experiments with it, such as
reacting it with 70% HClO4 to make nitrylperchlorate or reacting it with other compounds to make nitryl-compounds. I have a few special glass
syringes, which can be used for corrosive gases.
Maybe I should dry my HNO3, or mix it with P4O10 to absorb any water? The latter reaction probable also is quite violent and it may lead to formation
of N2O5, which cannot be used to make NO2Cl. Besides that, N2O5 is quite unstable and in some reports it is said to be capable of exploding,
apparently without any provocation.
I myself will do some research on safely drying HNO3, without formation of N2O5, and without decomposing the acid. If I find a satisfactory way of
dring HNO3 I may try this experiment again. Would conc. H2SO4 be a good diluent, does it hold any water sufficiently strong? Anyone has experience
with this?
Doing experiments with chlorosulfonic acid is not something which I do comfortably. The chemical is insanely reactive and corrosive, much more so than
I expected. Even stuff like PCl5 or POCl3 is quite tame, compared to chlorosulfonic acid.
[Edited on 18-12-17 by woelen]
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Bert
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| Quote: |
Maybe I should dry my HNO3, or mix it with P4O10 to absorb any water? The latter reaction probable also is quite violent and it may lead to formation
of N2O5, which cannot be used to make NO2Cl. Besides that, N2O5 is quite unstable and in some reports it is said to be capable of exploding,
apparently without any provocation.
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There is a procedure for making TNT from 2,4 dinitrotoluene posted here by a member using P4O10 and fuming nitric acid for the final nitration,
avoiding the need for making SO3 and then oleum. The procedure only mentions it being quite difficult initially to disperse the powdered P4O10 into
the nitric acid, as far as I can recall. Will look for this again.
I have never done this personally. AFAICR, the person who posted procedure did say he had done this.
(Edit)
Can't find it. Do find a TNT synthesis from DNT using 98% sulfuric acid, Phosphorus pentoxide and a nitrate salt.
Also several references to high purity nitrocellulose (no sulfates) synthesis via fuming nitric acid, phosphorus pentoxide and cellulose, no sulfuric
acid used.
Quote: Originally posted by killswitch  | I have achieved the nitration of dinitrotoluene in good yield via phosphorus pentoxide, 98.3% sulfuric acid, and sodium nitrate.
100 grams of P2O5 was added to 150mL of concentrated sulfuric acid with stirring. The P2O5 has an unfortunate tendency to form spherical bubbles that
refuse to dissolve. Extended periods of stirring are required to overcome this.
When the phosphorus pentoxide has dissolved, add 60 grams of dinitrotoluene and stir until it has dissolved. A slight darkening of the solution may be
noticed as the DNT is sulfonated at the remaining o/p position.
While maintaining the temperature between 100 and 110 celsius, add 105 grams of sodium nitrate over a period of approximately 1 hour.
Afterwards, allow the solution to stir at 100 celsius for two to four hours, then let it settle for 8-12 hours. Then separate from the acid and
perform the standard purification techniques. |
[Edited on 18-12-2017 by Bert]
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unionised
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Could you "dry" the nitric acid with conc sulphuric or oleum?
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EilOr
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Yes, you can dry HNO3 by vacuum destilling from conc. H2SO4
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kmno4
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| Quote: | | From literature I understood that ..... reaction is said to be smooth and complete |
Instead some suspicious literature, I would read Brauer, Inorganic Syntheses or something similar (and I did)
| Quote: | | ....contains quite some water (maybe 10%) |
Maybe 10, maybe 2, maybe 20.... Titration is a key 
Shotly:
100% HNO3 + cooling, more datails in those literature.
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XeonTheMGPony
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while looking into RDX production and methods of getting absolute HNO3 they referenced extracting the HNO3 from the mother liquor via DCM, then
distilling this under low temp under vacuum to leave the pure anhydrous HNO3.
http://www.sciencemadness.org/talk/viewthread.php?tid=73623
https://www.thevespiary.org/rhodium/Rhodium/www.roguesci.org...
Just a couple links that came up with recent search
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