Sciencemadness Discussion Board - Making Nitrosylsulphuric acid, NOHSO4

Making Nitrosylsulphuric acid, NOHSO4

plante1999 - 10-5-2012 at 03:58

I want to make nitrosylsulphuric acid and I have thought to a process and I would want to have some commentary about it.

First mixing NH4NO3 with 95% H2SO4 with a really great excess of sulphuric acid and wait a few hours, and then gravity decent from the NH4HSO4.(HNO3 sol. in H2SO4)

Then pass sulfur dioxide in the nitric/sulphuric acid mix to get a suspension of NOHSO4 in sulphuric acid ready to use it as a nitrite.

thanks!!

hissingnoise - 10-5-2012 at 05:02

Quote:

(From Wiki)
A typical procedure entails dissolving sodium nitrite in concentrated sulfuric acid in an ice bath:

HNO2 + H2SO4 → NOHSO4 +H2O

The molecule can also be viewed as the mixed acid anhydride of sulfuric acid and nitrous acid. Alternatively, it can be prepared by the reaction of nitric acid and sulfur dioxide.

When NH4NO3 is dissolved in a large excess of H2SO4 nitramide NH2NO2 is formed.

Quote:

. . . a suspension of NOHSO4 in sulphuric acid ready to use it as a nitrite.

NOHSO4 is soluble in sulphuric acid.

woelen - 10-5-2012 at 05:15

Quote:

When NH4NO3 is dissolved in a large excess of H2SO4 nitramide NH2NO2 is formed.

Are you sure about this? This is totally new to me. Could you please tell us from where you did get this information?

hissingnoise - 10-5-2012 at 05:38

No handy reference woelen, but it's dehydration by excess sulphuric acid; NH4NO3 minus H2O ---> NH2NO2.

AJKOER - 10-5-2012 at 06:23

2 NO2 + 2 SO2 + H2O2 --> 2 NOHSO4

Support for this synthesis, per Wikipedia:

"A typical procedure entails dissolving sodium nitrite in concentrated sulfuric acid in an ice bath:[2][3]
HNO2 + H2SO4 → NOHSO4 +H2O
The molecule can also be viewed as the mixed acid anhydride of sulfuric acid and nitrous acid. Alternatively, it can be prepared by the reaction of nitric acid and sulfur dioxide.[4]"

And as:

2 NO2 + H2O2 → 2 HNO3

the suggested synthesis is by the action of HNO3 on SO2.

Or, as:

H2SO3 + H2O2 --> H2SO4 + H2O

and:

NO2 + H2O --> HNO2 + HNO3

by the reaction of HNO2 and H2SO4.

Note, per Wikipedia, the thermal decomposition of Lead nitrate produces NO2:

2 Pb(NO3)2 → 2 PbO + 4 NO2 + O2

so neither concentrated H2SO4 or HNO3 are needed, but high concentration H2O2 may be required , or not, see comment below by Woelen recommending 10% H2O2 and boiling to make a more concentrated H2SO4 from SO2 and H2O2, which may be applicable to the synthesis of NOHSO4 also:

"Making H2SO4 from SO2 can be done in another way. Take some dilute HCl (not more than 15%), add sodium bisulfite (or potassium bisulfite), which can be purchased at wine/beer making stores as disinfectant and preservant. Then heat the solution to (almost) boiling. The SO2 now bubbles out of this solution, it does not dissolve well in hot water. And, if your HCl is not of too high concentration, you hardly will get any HCl with the SO2. By bubbling the SO2 (with small amounts of HCl in it) through H2O2 you make H2SO4. Heating this in turn drives off any small amounts of HCl, decomposes excess H2O2 and concentrates the solution.
Be careful with leading SO2 through H2O2 in this case. Use only 10% H2O2 (you can boil off water later on) and be careful for suckback. When production of SO2 is not fast enough or when heating is stopped, while the bubbling tube is still in the H2O2, then quickly liquid is sucked back and eventually may come in your HCl/bisulfite mix. This is a real risk, so be VERY careful.
You can use plastic/rubber tubing. The transparent tubes, sold in aquarium stores for oxygen pumps or filters is perfectly suitable. SO2 is not corrosive to those tubes (but it is to your lungs!, be careful)."
LINK: http://www.scienceforums.net/topic/13142-making-sulfuric-aci...

Also, one could replace Hydrogen peroxide all together with Ozone or HOCl (which introduces a side product of HCl). Note, if one prepares the Hypochlorous acid by the action of water on Dichloroisocyanuric acid (DCCA) please exercise care as the disproportionation of conc HOCl into HClO3 (and HCl) can liberate explosive ClO2 gas in the presence of Hydrochloric acid (at least one serious lab accident attributed to Chlorine dioxide from HClO3/HCl has been noted in prior Sciencemadness threads).

[Edited on 10-5-2012 by AJKOER]

plante1999 - 10-5-2012 at 08:17

I dont have H2O2.

You said that it make NH2NO2 by dehydratation, could the NH2NO2 be used to make isopropyl nitrite by mixing the sol. with isopropyl alcohol or be directly reacted with hydrazine to make azides. Since im planning to use the NOHSO4 for azide synthesis. I have thinked to something, if nitramine and urea is reacted in boilling sol could it make ammonium azide?

2NH2NO2 + 2(NH2)2CO -) 2CO2 + 2H2O + 2NH4N3

woelen - 10-5-2012 at 12:27

Quote: Originally posted by hissingnoise

No handy reference woelen, but it's dehydration by excess sulphuric acid; NH4NO3 minus H2O ---> NH2NO2.

Yes, I saw that nitramide has has the atoms of ammonium nitrate with exactly one molecule of water removed, but I have severe doubts on the real occurrence of dehydration in this particular case.

Ammonium nitrate can be dissolved in hot sulphuric acid and nitric acid can be distilled out of this mix and ammonium sulfate remains behind. If heating is too strong, then decomposition may occur with formation of N2O and H2O. But I never read about formation of NH2NO2 and I did a small search on google and I find no description about this reaction.

[Edited on 11-5-12 by woelen]

hissingnoise - 10-5-2012 at 15:11

Quote:

If heating is too strong, then decomposition may occur with formation of N2O and H2O.

The decomposition products of nitramide are N2O and H2O!

[edit]

This from Davis's COPAE:

Quote:

The solution which results when ammonium nit ‘5tLe is dissolved
in a large excess of concentrated sulfuric acid evidently
contains nitroamide.* If the solution is warmed directly, no nitric
acid distils from it but at about 150’ it gives off nitrous oxide
which corresponds to the dehydration of the nitroamide by the
action of the strong acid. The nitroamide moreover, by the action
of the same acid, may be hydrated to yield nitric acid, slowly if
the solution is digested at 90” to 120°, under which conditions
the nitric acid distils out.

[Edited on 10-5-2012 by hissingnoise]

AndersHoveland - 10-5-2012 at 17:06

Nitrosyl sulfuric acid is typically prepared by passing a mixture of nitric oxide and nitrogen dioxide into concentrated sulfuric acid.

3 H2SO4 + NO + NO2 --> 2 HSO4(NO) + HSO4(H3O)

Pure nitrosylsulfuric acid is actually a white solid at room temperature, but it dissolves in highly concentrated sulfuric acid. In lower sulfuric acid concentrations (30% for example), some of it can precipitate out as a solid, while in much more dilute sulfuric acid (or in plain water) the nitrosylsulfuric acid hydrolyses back into sulfuric acid and nitrogen oxides.

Also to mention, nitrosylsulfuric acid is chemically similar in many ways to another compound, nitrosyl perchlorate.
http://www.sciencemadness.org/talk/viewthread.php?tid=196

[Edited on 12-5-2012 by AndersHoveland]

plante1999 - 10-5-2012 at 17:16

So I tried something today in the objective to make isopropyl nitrite for azide production.

I tried a one pot synthesis of it with large excess of sulphuric acid.(based on stochiometry (starting with 5g NH4NO3)

2H2SO4 + 2NH4NO3 + Na2S2O5 -) 2NOHSO4 + Na2SO4 + (NH4)2SO4 + H2O

I mixed the sulfuric and the nitrate, then I cooled the sol. and putted it in cold water
I added small amount of metabisulfite, but I added isopropyl alcohol before adding all the metabisulfite, so a small runaway ocured with nitrogen oxides( proving that my mixture was indeed a nitrosyl!). then I added all the metabisulfite small amount at the time and the alcohol later on but I had already used all the nitrate with the runaway so nothing happened.....

A good point is that a small yellow layer was formed on top which correspond to the color of isopropyl nitrite, probably a lot less than it shhould have been made...

I used all my metabisulfite so I need to buy/make more of it.

Improvement that could be made:
Using ice/salt mixture in place of the cold water.
Adding slowly all the metabisulfite before the isopropyl alcohol
use mixing.
Use sodium or potassium nitrate in place of ammonium nitrate

Work need to be done in this way.

[Edited on 11-5-2012 by plante1999]

[Edited on 11-5-2012 by plante1999]

[Edited on 11-5-2012 by plante1999]

AndersHoveland - 10-5-2012 at 17:49

Nitrosyl sulfuric acid hydrolyses with water to form sulfuric acid and nitrous acid, which is given off as nitric oxide and nitrogen dioxide bubbles from the solution.

HSO3NO + H2O --> H2SO4 (aq) + HNO2
2 HNO2 <==> NO + NO2 + H2O

Apparently, however, nitrosyl sulfuric acid can precipitate out as solid crystals from 30 percent concentrated sulfuric acid, showing that the hydrolysis is an equilibrium reaction. But at much higher concentrations of sulfuric acid, the nitrosylsulfuric acid can again dissolve.

2 HSO4NO + H2O <==> 2 H2SO4 (aq) + NO + NO2

The Lead Chamber process is basically just the oxidation of sulfur dioxide by air to sulfuric acid, catalysed by nitric oxide. There just happens to be very complex reaction equilibria occuring in the process.

If one already has sodium nitrite and concentrated sulfuric acid, I see no reason why sulfur dioxide would be of any benefit for making nitrosyl sulfuric acid, because the sulfur dioxide will just get oxidized to sulfuric acid first, before it is forms nitrosylsulfuric acid. Although I suppose sulfur dioxide could be useful if one does not have access to nitric oxides, as the SO2 could reduce concentrated nitric acid, forming nitrogen dioxide as an intermediate, which would could then be absorbed by the sulfuric acid.

HNO3 + SO2 --> HSO4NO

I do not think this reaction would be very efficient, as the HNO2/NO2/HSO4NO would tend to oxidize the SO2 much more rapidly than the nitric acid. Higher concentrations of nitric acid would be expected to increase yields, as HNO3 reacts much more rapidly at higher concentrations, and is actually a stronger oxidizer than HNO2/NO2 or HSO4NO. However, I would not expect nitrosylsulfuric acid to be stable in the presence of very high concentrations of nitric acid. The nitrosyl ion, NO[+] would react with the nitrate ions, giving off nitrogen dioxide from the solution. This is not to say that HSO4NO cannot exist in the presence of nitric acid, just that as soon as the NO2 leaves the solution, the equilibrium will shift. In other words, it is best to use fairly concentrated nitric acid, but not too concentrated, perhaps 20-40% conc. ?

Quote: Originally posted by plante1999

2H2SO4 + 2NH4NO3 + Na2S2O5 --> 2NOHSO4 + Na2SO4 + (NH4)2SO4 + H2O

I suppose this makes sense. But it might be better to use potassium nitrate instead of ammonium nitrate. The ammonium ions could potentially be oxidized under these conditions, especially if there is significant heat, Although typically the oxidation of ammonium salts by nitrogen dioxide is relatively slow; see https://www.sciencemadness.org/whisper/viewthread.php?tid=18...
I do not know how fast nitrosyl sulfuric acid would oxidize ammonium ions. On the one hand, the NO[+] ion is more oxidizing than NO2, but on the other hand, both NO[+] and NH4[+] are positively charged, so would repel, making any reaction rate very slow. The nitrosyl group could also act as an oxidizer undissassociated into ions, still attached as part of the nitrosylsulfuric acid molecule.

In other words, the reaction might not work, or may give lower yields. But if it does work, it is probably not a good idea to let the nitrosylsulfuric acid sit around too long together with the ammonium sulfate byproduct from the reaction. You might want to immediately use the nitrosylsulfuric acid to react with something else.

One big disadvantage of using KNO3, however, is that it is much more difficult to dissolve in concentrated sulfuric acid. If I can make a suggestion, first finely crush the pellets of KNO3, then heat with the sulfuric acid to get it to first dissolve before adding anything else, and let it cool to room temperature. Then the sulfite (or metabisulfite) can be added, in small additions over a period of time. Do not add the sulfite all at once, this would just cause the SO2 to all bubble out. The sulfur dioxide is going to need some time to be oxidized, depending on the concentrations of acid. I do not know what an ideal length of time this should take, but would guess the sulfite should be added over a period of 8-15 minutes. If only 30% conc. acid is used, which is not advisable, then probably around 40 minutes. Adding the sulfite within too short of a period of time will just waste sulfite and the sulfuric acid required to react with it.

Nitrosylsulfuric acid can dissassociate into ions in sulfuric acid solution:

HSO4NO <==> HSO4[-] + NO[+]

Nitronium hydrogen sulfate also exists, and is the active agent responsible for nitrations in mixtures of oleum (superconcentrated sulfuric acid) with nitric acid.

HNO3 + SO3 --> HSO4NO2

HSO4NO2 <==> HSO4[-] + NO2[+]

[Edited on 11-5-2012 by AndersHoveland]

plante1999 - 11-5-2012 at 06:54

Well I used concentred sulphuric in excess to absorb the water. If this process is improuved I think it could be a really usefull process for synthesis of isopropyl nitrite as an intermediate for azide production.

hissingnoise - 11-5-2012 at 08:46

Using a nitrite ester has the advantage that NaN3 will precipitate from alcohol ─ using sodium nitrite will give a water soln. of the azide.
The soln. can, when neutralised, be used to prepare lead azide.

AJKOER - 11-5-2012 at 10:20

Quote: Originally posted by AJKOER

2 NO2 + 2 SO2 + H2O2 --> 2 NOHSO4

An interesting theoretical point on my suggested small scale synthesis of reacting NO2 and SO2 gases in the presence of an oxidizer is that the reaction proceeds with replacing the oxidizer with just water and air (or a very dilute oxidizer) as:

2 NO2 + H2O <---> HNO2 + HNO3

HNO3 + SO2 ---> NOHSO4

Or on net:

2 NO2 + SO2 + H2O ---> HNO2 + NOHSO4

However, per Wikipedia to quote:

"In anything other than very dilute, cold solutions, nitrous acid rapidly decomposes into nitrogen dioxide, nitric oxide, and water:

2 HNO2 → NO2 + NO + H2O "

Substituting, assuming a decomposition of Nitrous acid:

2 NO2 + SO2 + H2O ---> 1/2 NO2 + 1/2 NO + 1/2 H2O + NOHSO4

or :

3/2 NO2 + SO2 + 1/2 H2O --> 1/2 NO + NOHSO4

but with O2/air added, and as 1/2 NO + 1/4 O2 --> 1/2 NO2:

3/2 NO2 + SO2 + 1/2 H2O + 1/4 O2 --> 1/2 NO2 + NOHSO4

or:

NO2 + SO2 + 1/2 H2O + 1/4 O2 ---> NOHSO4

So, one mole of NO2 and SO2 still produces just one mole of NOHSO4, but a quarter of a mole of oxygen must be added to avoid side products and also that air, itself, may be a sufficient oxidizer for this reaction. Note, the comment by AndersHoveland: "The Lead Chamber process is basically just the oxidation of sulfur dioxide by air to sulfuric acid, catalysed by nitric oxide." And, in the current case, the sulfuric acid further reacts with NO2 forming Nitrosyl sulfuric acid. An important aspect of the suggested synthesis is the relative purity of the product.

[Edited on 11-5-2012 by AJKOER]

Nitrosylsulfuric Acid

barley81 - 11-5-2012 at 12:04

From Absorption of Nitrous Gases by H. W. Webb. This is from the Sciencemadness library.

[Edited on 11-5-2012 by barley81]

AndersHoveland - 11-5-2012 at 14:31

Quote: Originally posted by AJKOER

2 NO2 + SO2 + H2O ---> 1/2 NO2 + 1/2 NO + 1/2 H2O + NOHSO4

or :
NO2 + SO2 + 1/2 H2O + 1/4 O2 ---> NOHSO4

Yes, this is basically what happens in the lead chamber process. The formation of nitrosylsulfuric acid in the process is neither essential, nor desirable for the process, it just happens to be a complicating side reaction.

Remember, these are not "one-way" reactions. There are very complicated equilibria that will shift in different directions, depending on reactant concentrations and pH. The relationship between acid concentrations and equilibria is probably fairly complex, and certainly has non-linear effects. While oxides of nitrogen tend to be much less soluble in water under acidic conditions, in the case of more concentrated sulfuric acid the sulfuric acid seems to do just the opposite, keeping the nitrogen oxides in the solution, in the form of nitrosylsulfuric acid that exists in equilibrium.

Remember, most of these reactions we have mentioned are entirely reversible! Of course, the oxidation of SO2 is one-way in this process, but everything else exists in equilibrium.

I would wonder if anything would happen if sulfur trioxide was reacted with a mix of nitrogen dioxide and nitric oxide. Possibly "nitrosyl pyrosulfate" would form?

2 SO3 + NO2 + NO --> (NO)2S2O7

or if only nitrogen dioxide was passed in, perhaps "nitrosyl nitronium pyrosulfate"? sulfur trioxide is a very strong lewis acid, so it would not be surprising if nitronium ions could form.

2 SO3 + 2 NO2 --> ONO-SO2-O-SO2-O-NO2

[Edited on 12-5-2012 by AndersHoveland]

plante1999 - 12-5-2012 at 10:34

I'm planing to re-make my one pot synthesis of isopropyl nitrite for azide production in one week. I hope all the water produced in the reaction will be absorbed by the H2SO4

Reagent:
17g NaNO3 (NH4NO3 from instan cold pack reacted with sodium hydrogen carbonate and boiled down)
120g 95% H2SO4 (drain cleaner which seam to be highly pure for a consumer product (maybe Lab grade) (density tested for concentration))(3 time more than required)
19g Na2S2O5 (lab grade)
12g Isopropyl alcohol ( salted out of 70% sol. of pharmacy)

Procedure that I will do:
1-Make a ice/salt bath and put a beaker with sulphuric acid in it.
2-Dissolve slowly the sodium nitrate in the sulphuric acid keeping the temperature bellow 0
3-Add very slowly and with a lot of stirring the metabisulfite and keep the temperature bellow 0
4-add one drop at the time the isopropyl and keep the temperture bellow 0
5-take a pipete and take the isopropyl nitrite layer

2NaNO3 + 4H2SO4 + Na2S2O5 -) 2NOHSO4 + 4NaHSO4 + H2O

Feel free to comment!

Thanks!!

[Edited on 12-5-2012 by plante1999]

[Edited on 12-5-2012 by plante1999]

Nicodem - 12-5-2012 at 11:29

Quote: Originally posted by plante1999

Procedure that I will do:
1-Make a ice/salt bath and put a beaker with sulphuric acid in it.
2-Dissolve slowly the sodium nitrate in the sulphuric acid keeping the temperature bellow 0
3-Add very slowly and with a lot of stirring the metabisulfite and keep the temperature bellow 0
4-add one drop at the time the isopropyl and keep the temperture bellow 0
5-take a pipete and take the isopropyl nitrite layer

That is the most unlikely synthesis of isopropyl nitrite I ever saw. It seems unlikely you would obtain a clean nitrosation of an alcohol in concentrated sulfuric acid. What is the reference describing the O-nitrosation of alcohols with nitrosyl sulfuric acid in sulfuric acid? Are you sure the procedure did not call for a reverse addition of the a HSO3NO/H2SO4 mixture into a isopropanol/water mixture? That is the only thing that I can think of that would actually make sense.

O-Nitrosations of alcohols are usually performed in aqueous sodium nitrite acidified with sulfuric or other acids. In the case of water soluble alcohols, such as isopropyl nitrite, in homogeneous reactions, the nitrite esters separate as the top liquid layer.
http://www.erowid.org/archive/rhodium/chemistry/isopropylnit...
http://www.orgsyn.org/orgsyn/pdfs/CV2P0108.pdf

[Edited on 12/5/2012 by Nicodem]

plante1999 - 12-5-2012 at 11:49

In fact I am not an organic home chemist, I am more an inorganic/coordination home chemist.... I saw the procedure with sodium nitrite but I don't have any nitrite so I thought to use nitrosyl sulphuric acid since it is the anydride of nitrous and sulfuric acid. Nitrous acid is used in the original synthesis so I thougth it will work, I made my first test earlier and reported it on this thread, it did give me isopropyl nitrite but the condition in the reaction where far from optimal. I change some point in my earlier way to make isopropyl nitrite and I come up with this and as a said earlier I'm not an organic home chemist so I did not know that the reaction needed to be carried out in aqueous medium. You said that it would be better to ad the mix of nitrosylsulphuric acid in an aqueous solution of isopropyl alcohol, what concentration should I use?

Thanks!!!

[Edited on 12-5-2012 by plante1999]

[Edited on 12-5-2012 by plante1999]

Rosco Bodine - 12-5-2012 at 11:54

I have profound safety concerns about the proposed method of synthesis of plante1999 for isopropyl nitrite. It would seem much better to generate the nitrous gas via nitric acid and starch or paraformaldehyde and then do a gas dispersion into isopropyl alcohol for conversion of the alcohol to the nitrite, as has been done by Microtek.

Nicodem - 12-5-2012 at 13:14

Quote: Originally posted by plante1999

In fact I am not an organic home chemist, I am more an inorganic/coordination home chemist....

For designing experiments, it should not matter who you are as long as you do so in accordance with the scientific method. This means that what truly matters is what references you use and how well have you performed the literature work earlier. The evaluation of the results is then another problem which can only be solved by an equally strict adherence to the scientific method. You can't just make up things out of the blue, or whatever that anglo-saxon saying says. Doing so will only cause you grief and frustrations, while it will not contribute anything to your knowledge and skills.

Quote:

Nitrous acid is used in the original synthesis so I thougth it will work, I made my first test earlier and reported it on this thread, it did give me isopropyl nitrite but the condition in the reaction where far from optimal.

You mean this:

Quote:

I mixed the sulfuric and the nitrate, then I cooled the sol. and putted it in cold water
I added small amount of metabisulfite, but I added isopropyl alcohol before adding all the metabisulfite, so a small runaway ocured with nitrogen oxides( proving that my mixture was indeed a nitrosyl!). then I added all the metabisulfite small amount at the time and the alcohol later on but I had already used all the nitrate with the runaway so nothing happened.....

A good point is that a small yellow layer was formed on top which correspond to the color of isopropyl nitrite, probably a lot less than it shhould have been made...

OK, you made an experiment and you draw some conclusions, but you don't base your conclusions on conclusive evidence. Remember the scientific method!
How can you say that something is isopropyl nitrite just because its color corresponds? How do you know it is not isopropyl nitrate or something else in a mixture of whatever? Fumes of nitrous oxides sounds like the usual oxidation that occurs when mixing alcohols with HNO3/H2SO4 under runaway conditions, in the context of which your exclamation of "proving that my mixture was indeed a nitrosyl!" makes no reason. How could that prove you obtained nitrosyl sulfuric acid in the mixture when the same reduction of HNO3 occurs also in the absence of sulfur dioxide? As Rosco said concisely, this also raises profound safety concerns.

It seems to me that nitrosyl sulfuric acid is not your goal and that instead you just want to prepare some alkyl nitrite. Isopropyl nitrite is a bad choice due to its volatility. Even if you opt for the butyl or pentyl nitrite, the volatility is still high and you will better have a good fume hood or else you might become dizzy or faint from the CNS effects of the nitrite esters. The only time I prepared butyl nitrite (via Org. Synth.), I become dizzy just from cleaning the glassware and consequently broke a flask (should have left it in the fume hood to decontaminate first).
Anyway, if you want isopropyl nitrite, you better do modifications based on a verified procedure. Rosco gave you some good advice on what to use instead of sodium nitrite. If applying a gassing setup is too troublesome for you, you could consider doing the reduction of nitric acid in situ. Dilute nitric acid can not effectively O-nitrate alcohols while the nitrous acid can O-nitrosate them. Therefore a mixture of diluted (say 1 or 2M) nitric acid and isopropanol might give isopropyl nitrite if a reducing reagent such as copper is used (the blue of the copper will additionally make for the kewlish color effect, if kewlishness is your thing). Use about 4 equivalents of HNO3 over isopropanol and apply good stirring. It might not work, but at least it is effortless.

plante1999 - 12-5-2012 at 13:36

I'm not knew at all. Maybe I am not as experienced as other but I never use chemicals in the objective to make explosives to be honest I had never made energetic material for knew things, the sodium azide that I want to make is indeed intended to reproduce the azide complex of cobalt. Like I said I had none experience in O-chem before this reaction. I just wanted to know opinion of everybody on sm to know it I should do the synthesis that I thought. Anyway I would like to know your opinion on this idee, if i make nitrosylsulphuric acid sol. by ''my'' process and I use a vacuum flask with a dispensing funnel in a stopper hole. The flask filled with the sol.. of nitrosyl and the funnel with hot water. Adding hot water slowly will make NO2+NO Than pass the gas with a gas dispersion tube in isopropyl alcohol will it be safe and will it work?

On A side note I know that the yellow liquid could be a mix of chemicals but it burned with a distinctive flame like in this video:http://www.youtube.com/watch?v=ygAxh81WaWg

Another thing: thanks for your comments it was the type of comment that I wanted.

plante1999 - 14-5-2012 at 08:04

Rosco said that I could pass NO2+NO in the isopropyl alcohol water mix. I can only get ammonium nitrate as the nitrite precursor. Could I make nitrosylsulphuric acid with ''my'' process and then add water on the nitrosyl salt to generate the NO2+NO. How could I make NO2+NO mix from ammonium nitrate/sodium nitrate as the precursor?

thanks!!

barley81 - 14-5-2012 at 08:37

Here is an idea:
Boil the ammonium nitrate with baking soda or sodium carbonate to obtain sodium nitrate. Melt this and react it with lead (procedure is somewhere on the forum) to produce sodium nitrite. You get litharge as a byproduct.

React the sodium nitrite with HCl and isopropanol (you know this one already) to get isopropyl nitrite.

plante1999 - 14-5-2012 at 14:01

I already read the lead-nitrate process but I do not really like it since it is very ineffective from what I read on this forum. I looked in brauer handbook of inorganic chem and it seam that nitrosylsulphuric acid is used for NO2/NO production. What would be the reaction if 99% HNO3 is reacted with anhydrous oxalic acid?

edit: I made some nitrosylsulphuric acid with ammonium nitrate using ''my'' process without cooling, no nitrogen oxides where produce, then I added water 0.5ml at the time. the first 0.5ml no gas where produce, at 3 drop of 0.5ml gas production started at a steady rate and the maximum effervescence was observed at 5 drop of 0.5ml. I am very happy of the result since now it prove the formation of nitrosylsulphuric acid. I am proud of my synthesis!

Thanks!!!

[Edited on 14-5-2012 by plante1999]

[Edited on 14-5-2012 by plante1999]

plante1999 - 16-5-2012 at 17:14

Quote: Originally posted by Nicodem

If applying a gassing setup is too troublesome for you, you could consider doing the reduction of nitric acid in situ. Dilute nitric acid can not effectively O-nitrate alcohols while the nitrous acid can O-nitrosate them. Therefore a mixture of diluted (say 1 or 2M) nitric acid and isopropanol might give isopropyl nitrite if a reducing reagent such as copper is used (the blue of the copper will additionally make for the kewlish color effect, if kewlishness is your thing). Use about 4 equivalents of HNO3 over isopropanol and apply good stirring. It might not work, but at least it is effortless.

Wow this was a really really great idea!
I mix 40g of water 16g of ammonium nitrate 30g of 95% H2SO4 to make my HNO3 sol. , I poured it in a flask in a bucket of cold water.

Then I added 2g of copper and all 12g of isopropyl alcohol 1ml each 45 second to the nitric acid. then the last 12g of copper where added(slightly more than needed).

The reaction is running really slowly giving no nitrogen oxides and after 15minutes there was a yellow green layer forming on top! The reaction is still running overnight and I expect really great yield. thanks Nicoderm! tommorow I will test my product. How can I clean the isopropyl nitrite?

2NH4NO3 + 2Cu + 3H2SO4 + 2IPr(OH) -) (NH4)2SO4 + 2CuSO4 + 4H2O + 2IPr(NO2)

thanks all!

Isopropyl nitrite purity

plante1999 - 17-5-2012 at 06:26

I made some isopropyl nitrite but I am not sure if it is isopropyl nitrite.
How can I test it? Also I want to wash it and I dont know how to do it.

My isopropyl nitrite is a yellow-green liquid making a layer on saline solution.

The isopropyl nitrite is for azide production.

thanks!!!

[Edited on 17-5-2012 by plante1999]

Mailinmypocket - 17-5-2012 at 09:00

Are you looking to determine purity in the sense of contaminants present in the final product or are you looking for a way to find out if the product is isopropyl nitrite?

By your description it sounds identical to the isopropyl nitrite I made. You could trythis test for nitrites, it applies to aqueous nitrites and I'm not sure if it would work for alkyl nitrites given the insolubility in water... Im fairly sure you have isopropyl nitrite though.

Care to share the procedure you followed? I used the one from len's book "Small-Scale Synthesis of Laboratory Reagents with Reaction Modelling" and it worked very well.

Washing can be done by shaking with distilled water and separating the phases, repeat 2-3 times. I dried mine over anhydrous sodium sulfate also.

[Edited on 17-5-2012 by Mailinmypocket]

Nicodem - 17-5-2012 at 14:06

Quote: Originally posted by plante1999

I made some isopropyl nitrite but I am not sure if it is isopropyl nitrite.

That is a nice and illustrative example of an oxymoron. You can use the derivatives of the word "presume" for declaring identity without having any evidence. It sounds better and you don't end up contradicting yourself.

Quote:

How can I test it? Also I want to wash it and I dont know how to do it.

First the most elementary data: What is its boiling point?

Separatory funnels are the equipment used for performing washings or any other operation involving liquid-liquid phase separation. Alternatively, for small volumes, you can use a pipette to separate phases.

Quote:

How can I clean the isopropyl nitrite?

Volatile liquids are generally isolated and purified by distillation, usually using a fractionating column if the contaminants are also volatile.

Edit: You should use at least 3 to 5 times more water in your experiment. The reaction mixture is too concentrated - formation of nitrates can be a competitive reaction at such conditions. Formation of a liquid layer is also no conclusive indication of the desired esterification, because isopropanol forms a biphasic mixture with aqueous solutions of many salts (it "salts out").

Also, don't cross-post anymore. Opening another thread on the topic and furthermore without giving the reference to this previous discussion, like you did, can only cause confusion. Read the forum guidelines for posting.

[Edited on 17/5/2012 by Nicodem]

Scr0t - 19-2-2013 at 14:58

I made this by passing SO2 from a Sulfur burner/candle into HNO3 (100ml) according to Brauer.
I used the suction of a water aspirator to draw SO2/air through the apparatus. However the aspirator flow rate wasn't really sufficient (it took 12hrs to burn ~100g S, theoretical predicted ~5hrs) by which the point the HNO3/NOHSO4 mix had become yellow, viscous and opaque with small gas bubbles in suspension, no solids had separated.

Addition of this liquid to an equal volume of AcOH caused immediate deposition of white solids that were filtered and dried in a desiccator. Yielding only 42% NOHSO4 based on HNO3, I may have been too liberal with the AcOH.
The material rapidly reacts with water to generate a blue-green liquid and copious amounts of NOx.

An earlier attempt on the same scale above which used a wet slush of Sodium Metabisulphite and dropwise addition of aqueous H2SO4 (50% /v) to generate the SO2 proceeded smoothly at first but after about half the acid had been added SO2 generation became erratic causing the mass to heave releasing strong bursts of SO2.
By the the time I considered disconnecting the generator the HNO3 suddenly began boiling, blowing out the Dreschel head and spraying hot HNO3/NOHSO4 for several feet in-spite of the ice-salt bath cooling.
So if Metabisulphite is used then use much more water and a very gradual temperature ramp to drive out dissolved SO2.

AndersHoveland - 20-2-2013 at 04:16

Quote: Originally posted by hissingnoise

When NH4NO3 is dissolved in a large excess of H2SO4 nitramide NH2NO2 is formed.

No handy reference woelen, but it's dehydration by excess sulphuric acid; NH4NO3 minus H2O ---> NH2NO2.

As for trying to dehydrate ammonium nitrate with sulfuric acid,

Quote:

When ammonium nitrate is heated with a large excess of concentrated sulfuric acid, about 85% of its nitrogen is given off as nitrous oxide, the rest in its elemental state. The dehydration does not become rapid until 150 °C.
"The Dehydration of Ammonium Nitrate", Tenney L. Davis, Armand J. J. Abrams, J. Am. Chem. Soc., 1925, 47 (4), pp 1043–1045

"Ammonium nitrate heated with two equivalents of sulfuric acid behaves in the normal matter and yields nitric acid" [rather than dehydration of the ammonium nitrate]
Pelouze, Ann. chim. phys., [3] II, 47 (1841)

In another topic in this forum, "Why can concentrated sulfuric acid not be used to make RDX ?", one of our members posted a Chinese reference which stated that RDX reacts with sulfuric acid to form formaldehyde, nitrosylsulfuric acid, nitrogen, and water. Presumably the acid causes hydrolysis of the RDX first, and then the NH2NO2 immediately reacts.

Quote:

(CH2NNO2)3 + 2 H2SO4 --> 3 HCHO + 2 O2S(OH)ONO + 2 N2 + NO2

So the dehydration of NH4NO3 with H2SO4 might indeed be a route to prepare nitrosylsulfuric acid, if dehydration to nitramide can initially happen as an intermediate.

On the other hand, I would think nitrosylsulfuric acid would immediately react with any nitrate to liberate nitrogen dioxide.

NO₃^- + NO⁺ --> 2 NO₂

Is this NO2 going to just escape from the reaction? Or will it be transformed into something else?
(NO2 is known to be able to slowly oxidize NH4+, particularly in boiling solution, but this potential reaction pathway is probably not going to be of any importance here since the NO2 is likely to go somewhere else first)

Although these references I have presented may not seem to support hissingnoise's assertion, I am still inclined to think that nitrosylsulfuric acid could be formed. It might be best to gradually add the NH4NO3 to a large excess of conc. sulfuric acid.

I am not entirely sure, but I suspect the NO2 would be withheld in highly concentrated sulfuric acid, in the form of nitronium hydrogen sulfate, together with nitrosylsulfuric acid. (nitronium hydrogen sulfate exists, at least as an intermediate, in common mixed acid nitration reactions)

Quote: Originally posted by Nicodem

Except that isopropanol is fairly vulnerable to oxidation. If left to stand for any length of time with moderately concentrated nitric acid, it is likely to be initially oxidized to acetone, and then rapidly to further oxidation products (since acetone tautomerizes to its enol, especially under acidic conditions). Nicodem, your proposed reaction route might work better with ethanol or methanol... or n-propyl alcohol...

Nitrous acid might have a much faster reaction rate, but even moderately concentrated nitric acid is a more powerful oxidizer (because of nitronium NO₂⁺ ions in equilibrium).

[Edited on 20-2-2013 by AndersHoveland]