Sciencemadness Discussion Board - chlorine azide

chlorine azide

woelen - 25-5-2008 at 11:10

In one of my books, the existence of a compound ClN3 was mentioned, but without description of how to make it. Only details given were that it is made from a hypochlorite and an azide.

I tried the following in a miniature thick-walled test tube (7 ml):
- dissolve 50 mg of NaN3 in 1 ml of water.
- dissolve 150 mg of Ca(OCl)2 (swimming pool, 65% active chlorine) in 2 ml of water. No real solution was obtained, it is more like a white suspension/slurry.
- pour the slurry in the solution of sodium azide.

At this point nothing happens.

Next, I added two drops of concentrated hydrochloric acid. This results in formation of chlorine (green color of gasmix). Next, I swirled the solution. This results in formation of tiny bubbles of a colorless gas. The chlorine gas quickly was replaced by this gas. This formation of fine bubbles lasted for 15 seconds or so.

Next, I took a cigarette lighter and kept this near the little test tube. This resulted in a very loud high pitched report. It was really scary to have such a loud explosion from just a few ml of highly impure gas (mixed with air and chlorine)

.

When too much acid is used, then only chlorine gas is produced. Apparently the amount of acid must be such, that only part of the hypochlorite is converted to HOCl.

I think that this reaction requires HN3 and HOCl in solution, but it is not critical if some excess ClO(-) is left in solution:

HN3 + HOCl --> ClN3 + H2O

[Edited on 25-5-08 by woelen]

Polverone - 25-5-2008 at 12:27

Systematic Inorganic Chemistry has this to say:

Quote:

Attention has already been called to the similarity between the
azides and halides, and this similarity suggests that azide compounds
similar to ICl, ICN, and other interhalogen compounds might exist.
The colorless gas chlorine azide, ClN3 , results when an aqueous mixture
of sodium hypochlorite and azide is acidified with acetic or boric acid
[Raschig, Ber., 41, 4194 (1908); Glen, Z. physik., 38, 176 (1926)]; the
compound is highly and dangerously explosive. Bromine azide, BrN3 ,
is prepared by treating silver or sodium azide with a solution of bromine
in ether or benzene, or by letting bromine react with dry sodium azide.
BrN3 is a mobile, volatile, orange-red liquid which freezes to a red solid
at about -45 [Spencer, J. Chem. Soc., 127, 217 (1925)]. With water,
hydrolysis sets in and the resulting hydrazoic acid is oxidized to nitrogen.
BrN3 is probably explosive. Iodine azide, IN 3 , is an unstable, light-
yellow solid which is formed when an aqueous suspension of AgN3 is
treated with an ether or benzene solution of iodine. IN3 is somewhat
soluble in water and is hydrolyzed by alkali [Hantzsch, Ber., 33, 522
(1900); Gutman, Ber., 67, 1956 (1924)].

The Berichte paper mentioned appears to be from a few years after the Gallica digital copies cut off, unfortunately, but the material show here indicates that you should be able to prepare it in a purer state (if you desire) by using an acid that is not so readily oxidized.

Axt - 25-5-2008 at 12:30

If your book didnt contain references, this is the original preparation which uses acetic acid in place of the HCl.

F. Raschig "Über Chlorazid N<SUB><FONT SIZE='-1'>3</FONT></SUB> Cl" Berichte der deutschen chemischen Gesellschaft, 41[3], 4194-4195 (1908)
http://dx.doi.org/10.1002/cber.190804103130

Also you'll find some properties and reactions in the attached article JACS, 1943; 65(9) pp 1696 - 1698.

Attachment: Chlorine Azide.pdf (369kB)
This file has been downloaded 1311 times

The_Davster - 25-5-2008 at 12:31

And in case you feel like iodine azide:

Attachment: iodine azide.pdf (685kB)
This file has been downloaded 1752 times

Formatik - 26-5-2008 at 14:38

Based on Federoff, chlorine azide is also apparently highly poisonous.

BromicAcid - 26-5-2008 at 15:05

As one would expect from the toxicity of the azide Shockwave.

Don't remember the source but here is a scan regarding the properties and preparation of the halogen azides. This is already posted somewhere on the forum but I couldn't find the thread readily.

Halogen Azides

Zinc - 27-5-2008 at 08:28

Woelen, will you make a web page about chlorine azide?

woelen - 27-5-2008 at 10:56

I might make a web page about it, but before I do so, I first need some safe means of handling it while making videos and so on. A normal test tube is not safe with this gas. If it explodes (and it can explode apparently without reason) then a normal test tube almost certainly is shattered and glass will be around everywhere, including my body.

I am not really afraid of the toxicity. It is non-cumulative and I only make mg quantities (test tubes full of gas). The main problem is the unpredicatable highly explosive properties, which really scares me and especially when I make videos and pictures, then I do not want to scare the shit out of me, that while I am handling all kinds of things simultaneously that my apparatus is reduced to powder, as mentioned in the article, posted above.

I first will concentrate on the interesting properties of molybdenum chemistry and the complexes it forms

[Edited on 27-5-08 by woelen]

Iodine azide

Formatik - 28-5-2008 at 11:10

Gmelin says iodine azide is extraordinarily explosive when dry, and explodes more easily than nitrogen iodide. Its explosive decomposition products are N2 and I2. Even touching the substance with a glass rod can cause explosion, an explosion can also result without direct contact like by vigorous removal of the lid of a dessicator it is in. In solution as well as in the dry state it is said to have an extremely penetrating odor which reminds of ICN.

At low temperatures it is easily soluble in water and more easily in ether, less so in C6H6 and CHCl3, only moderatley soluble in petrol ether and alcohol. Its solutions decompose spontaneously at 0º slowly under the formation of I2 and N2. Especially easily decomposed is the aqueous solution, where HN3 and HIO are formed, which then converts into I2 and HIO3.

woelen - 25-6-2009 at 10:50

I again made some chlorine azide. This can be made more easily and more controlled than as I did last year. You indeed need a weak acid.

I dissolved some NaN3 in simple household bleach (4% active chlorine). I probably had a slight excess of household bleach. The solution is very pale green/yellow, also colorless.
To this solution I added half a ml of acetic acid (80%). As soon as a drop of the acid comes into the liquid, it becomes golden yellow and it starts bubbling vigorously, without getting warm. When the liquid is swirled, then more bubbles of gas are produced and the liquid becomes nicely golden yellow.

When bubbling stopped, I took a petri dish, covering the open end of the test tube and then turned it upside down, in a bucket of water with some soap in it. When it was upside down, I removed the petri dish. The yellow liquid quickly sinks to the bottom and the test tube remains filled with the colorless gas.

Then I slowly allowed bubbles of gas to escape to the surface and kept the flame of a cigarette lighter near the bubbles of gas on the water surface. Even a single bubble of 1 cm diameter (less than 0.5 ml of gas) gives an amazingly loud high pitched report, when it is lighted. The gas is increadibly explosive and the power of the explosion certainly is comparable to that of an ideal 2 : 1 stoichiometric mix of H2 and O2 (detonating gas). I'm quite sure that the ClN3 was not really pure, it had a faint yellow/green color, indicating that quite some chlorine was contained in the gas mix.

Right now I have appr. half of the test tube with the gas mix standing upside down in cold water. The chlorine will dissolve in a few hours, the ClN3 does not. So, I hope to get some pure ClN3 and then I'll repeat the test with a little bubble of gas.

JohnWW - 25-6-2009 at 13:27

Quote: Originally posted by Polverone

Systematic Inorganic Chemistry has this to say:

Quote:

Attention has already been called to the similarity between the
azides and halides, and this similarity suggests that azide compounds similar to ICl, ICN, and other interhalogen compounds might exist. The colorless gas chlorine azide, ClN3 , results when an aqueous mixture of sodium hypochlorite and azide is acidified with acetic or boric acid [Raschig, Ber., 41, 4194 (1908); Glen, Z. physik., 38, 176 (1926)]; the compound is highly and dangerously explosive. Bromine azide, BrN3 , is prepared by treating silver or sodium azide with a solution of bromine in ether or benzene, or by letting bromine react with dry sodium azide. BrN3 is a mobile, volatile, orange-red liquid which freezes to a red solid at about -45 [Spencer, J. Chem. Soc., 127, 217 (1925)]. With water, hydrolysis sets in and the resulting hydrazoic acid is oxidized to nitrogen. BrN3 is probably explosive. Iodine azide, IN 3 , is an unstable, light- yellow solid which is formed when an aqueous suspension of AgN3 is treated with an ether or benzene solution of iodine. IN3 is somewhat soluble in water and is hydrolyzed by alkali [Hantzsch, Ber., 33, 522 (1900); Gutman, Ber., 67, 1956 (1924)].

Direct link to download Systematic Inorganic Chemistry:
http://www.archive.org/download/systematicinorga031822mbp/sy... 18.0 Mb
- Systematic Inorganic Chemistry - D M Yost & H Russell (PH-1946)

woelen - 26-6-2009 at 00:57

I now have done the experiment with more pure ClN3. After an hour or so, the volume of gas above the water only was half of that which I had initially. The water itself had a faint green color and the gas above the water was perfectly colorless. So, the green gas I had indeed was chlorine and the colorless gas which remained is ClN3 (probably mixed with some air). I ignited some bubbles of this gas and the force of the explosion is increadible. It really is amazing that such a small amount of material can give such a loud noise (1 ml of gas is just in the order of mg of material!).

This method of generating ClN3 and then keeping it over water to get rid of chlorine also gives the opportunity to make the gas in a pure state. Next time I might dissolve some of the gas in an organic solvent and do some other less explosive experiments with it.

Formatik - 27-6-2009 at 18:29

That sounds spectacular woelen. The references also report the same thing about a loud report from tiny amounts. Citing Raschig, Gmelin states:

An explosion can be demonstrated harmlessly by placing a pinch of crystalline boric acid onto a block of wood, this is moistened with a drop of a mixture of equal parts of a n-NaN3 solution and n-NaClO solution. The resulting tiny gas bubbles explode on contact with a burning splint giving a loud report.

Attachment: ClN3.pdf (1.3MB)
This file has been downloaded 1088 times

PHILOU Zrealone - 11-7-2009 at 11:01

Some more infos:

Out of Hazards in the Chemical Laboratory (edited by G.D. Muir/The Chemical Society(London), second edition 1977):
p 185-Chlorine azide:
"Hazardous reactions: Extremely unstable, usually exploding violently without cause."
p 159-Bromine azide:
"Hazardous reactions: Very shock-sensitive in solid, liquid and vapour forms.
Liquid explodes on contact with As, Na, Ag(foil), P."
p 269-Fluorine azide:
"Hazardous reaction: Unstable-explodes on vapourisation (at -82°C)"
p288-Iodine azide:
"Hazardous reaction: Shock- and friction-sensitive explosive."

Out of Chemistry of the Elements (N.N. Greenwood and A.Earnshaw- Butterworth Heinemann, 1995):
p 964- 17.2.3 Interhalogen compounds:
"The chemistry of iodine azide has been reviewed (49)-it is obtained as volatile golden yellow, shock-sensitive needles by reaction of I2 with AgN3 in non-oxygen-containing solvents such as CH2Cl2, CCl4, or benzene: the structure in the gas phase (as ith FN3, ClN3, and BrN3 also) comprises a linear N3 group joined at an obtuse angle to the pendant X atom, thereby giving a molecule of Cs symmetry."
...
"49-K.DEHNICKE, The chemistry of iodine azide, Angew. Chem., Int.Edn. (Engl.) 18, 507-14 (1979)"

[Edited on 11-7-2009 by PHILOU Zrealone]

entropy51 - 11-7-2009 at 14:02

Fear not. Woelen seems to have a real gift for creating explosions that stop just short of generating shrapnel.

But hopefully he will soon lose interest in ClN3. I predict that cacodyl is on his "TO DO" list.

woelen - 16-7-2009 at 13:19

No, my interest in ClN3 has not gone yet. I'm still considering making a web page about this compound. There is some kind of background process in my mind which slowly seeks a way to do the experiment in a spectacular, but safe way, in such a way that it also can be filmed safely

Usually such background processes run for weeks but in most cases the result is something interesting and useful. So, just wait and see

Cacodyl is not on my wish list. Actually, I am quite 'afraid' of compounds which are toxic and can give all kinds of cumulative and chronic effects. I'm more scared of e.g. mercury and its salts than of Cl2, Br2 or even ClN3. I have the feeling that I better can manage acute risks than the sneaky and elusive risks of cumulative poisons. That's why you see so few experiments with mercury, arsenic, cadmium on my website.