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Nitryl Chloride

AndersHoveland - 1-2-2013 at 01:16

I have a question about nitryl chloride, NO2Cl.
Can it be prepared by direct combination of nitrogen dioxide with chlorine?

How stable is it? Is there an equilibrium under normal conditions with NO2 and Cl2 ? Or is NO2Cl stable at ambient temperature?

Does the chemistry of NO2Cl have any similarities to nitrosyl chloride, NOCl ?

I just cannot seem to find much information on nitryl chloride.
Although I did find this:

Quote:

Nitryl Chloride

CAS Registry Number: 13444-90-1
Molecular Formula: ClNO2

Literature References: Conveniently prepd by the addn of chlorosulfonic acid to nitric acid: Dachlauer, DE 509405 (1929 to I. G. Farben); Kaplan, Schechter, Inorg. Synth. 4, 52 (1953); Collis et al., J. Chem. Soc. 1958, 438.

Properties: Corrosive, toxic, colorless gas. Chlorine-like odor. Vapor density (100°): 2.81 g/l. Dec >120°. bp -14.3°. mp -145°. Even the purest liquid may have a pale yellow color. Solns in polar solvents are always yellow. The gas or liquid may attack organic matter with explosive violence.

Melting point: mp -145°
Boiling point: bp -14.3°

Use: Nitrating and chlorinating agent in organic syntheses.

Nitryl chloride was also made by reacting N2O5 with hydrogen chloride in sulfuric acid.
"Heterogeneous Interaction of N2O5 with HCl Doped H2SO4 under Stratospheric Conditions: ClNO2 and Cl2 Yields", Ranajit K. Talukdar, J. Physical Chem. A, 2012, 116 (24), pp 6003–6014

One source mentioned that:

Quote:

Nitryl fluoride and chloride are stable, well-characterized gases at room temperature.

But also stated that there is an equilibrium between NO2, Br2, and NO2Br.
David E. Tevault, J. Phys. Chem., 1979, 83 (17), pp 2217–2221

[Edited on 1-2-2013 by AndersHoveland]

Adas - 1-2-2013 at 13:29

I have also thought about NO2Cl as a nitrating agent. It would be cool if one could prepare it from KNO₃ and SO₂Cl₂

EDIT: I am starting to feel confident with the reaction I provided, because it shows similarity to the reaction of H2SO4 and KNO3, which forms HNO3 and KHSO4. SO2Cl2 is not a cheap substance, though.

[Edited on 2-2-2013 by Adas]

AJKOER - 2-2-2013 at 14:59

Here is a good referece on Nitryl chloride (http://site.iugaza.edu.ps/bqeshta/files/2010/02/94398_16.pdf ). On preparation, to quote:

"Nitryl chloride is prepared most conveniently by reacting chlorosulfonic acid with anhydrous nitric acid at 0°C: An older preparation method involves passing dry chlorine gas slowly over dry silver nitrate heated to about 100°C. The gaseous reaction products are allowed to cool to low temperature. After several hours, nitryl chloride condenses to a pale yellowish-brown liquid. Chlorine is removed by purging with CO2.

2AgNO3 + 2Cl2 → 2NO2Cl + 2AgCl + O2

Reactions
Nitryl chloride hydrolyzes in water forming nitric acid and hydrochloric acid:

NO2Cl + H2O → HNO3 + HCl"

An interesting comment is:

"Reaction with sodium hydroxide forms sodium nitrite and sodium hypochlorite:

2NaOH + NO2Cl → NaNO2 + NaOCl + H2O "

which suggests a convenient path to Nitrite salts and chloride-free hypochlorite. An important note:

"Nitryl chloride is a strong oxidizing agent. It reacts explosively with reducing agents."
--------------------------------------------------------------------

Per my prior thread reference detailing a Patent on the use of polarized uv radiation to directly combine Cl2 and O2 (see http://www.freshpatents.com/-dt20100204ptan20100025226.php ):

Cl2 + 2 O2 --Polarized uv--> 2 ClO2

the author notes that air cannot be employed due to the formation of cross products with nitrogen. So the answer to one of your questions is apparently yes as I suspect:

N2 + O2 + Cl2 --Polarized uv--> 2 NOCl

Also, per Wikipedia, to quote: "Another method of producing nitrosyl chloride is by direct union of the elements at 400 °C:

N2 + O2 + Cl2 → 2 ClNO"

However, another test reference below gives this reaction as reversible while the polarized uv approach is not.

Proceeding, if one has more N2 and O2 relative to Cl2, it is possible:

2 NO + O2 --> 2 NO2

And, per this brief reference (see http://www.lahc.edu/classes/chemistry/arias/102E1sp12sol.pdf ):

NO2Cl(g) + NO(g) <⇄> NOCl(g) + NO2(g)

and assuming more O2 added to this equilibrium as 2 NO + O2 --> 2 NO2:

2 NO2Cl + 2 NO + O2 <⇄> 2 NOCl + O2 + 2 NO2

Or, upon cancelling out "2 NO2":

2 NO2Cl <----> 2 NOCl + O2

and I do have some recollection of seeing this reaction before in a google book, but here is a test reference link citing this equation: http://blamp.sites.truman.edu/files/2012/03/Quiz-9-Key.pdf
------------------------------------------------------------------------

Per this source (link: http://www.pnas.org/content/99/19/12061.full.pdf ):

HOCl + NO2- + H+ --> NO2Cl + H2O

The author notes that low pH favors the reaction. As such, assuming this is not a reversible reaction, one could cautiously combine an excess of conc H2SO4 with say a mixture of NaNO2 dissolved in HOCl. The NO2Cl is hopefully expelled from the reaction mixture and captured. Interestingly, per AndersHoveland cited reference, to quote, "Heterogeneous Interaction of N2O5 with HCl Doped H2SO4 under Stratospheric Conditions: ClNO2 and Cl2 Yields", one here has H2SO4 acting on HOCl doped with N2O4 and NO.

An interesting reaction per this source http://www.techneau.org/fileadmin/files/Publications/Publica... :

NO2Cl + HNO2 <--> N2O4 + HCl

Now as:

2 HNO2 → NO2 + NO + H2O

An implied reaction is:

2 NO2Cl + NO + NO2 + H2O --> 4 NO2 + 2 HCl

or:

2 NO2Cl + NO + H2O --> 3 NO2 + 2 HCl
--------------------------------------------------------

[Edited on 3-2-2013 by AJKOER]

AndersHoveland - 2-2-2013 at 16:19

Quote: Originally posted by AJKOER

"Reaction with sodium hydroxide forms sodium nitrite and sodium hypochlorite:

2NaOH + NO2Cl → NaNO2 + NaOCl + H2O "

I am not so sure. This might be what forms initially, but I am fairly certain that hypochlorite will oxidize nitrite to nitrate. Sodium nitrite is a reducing agent, and its solutions are slowly oxidized in air to sodium nitrate.

AJKOER - 2-2-2013 at 19:22

AndersHoveland:

I was viewing the reaction a little more favorably as follows:

2 NaOH (s) + NO2Cl (g) --> NaNO2 (s) + NaOCl (s) + H2O (g)

In words, NO2Cl gas is passed over warm, perhaps moist, NaOH and the water vapor either escapes or forms a hydrate. In highly alkaline conditions, NO2 on NaOH will form NaNO2. In my opinion:

NO2Cl + HOH --> HOCl + HNO2 (neutral to high pH) --> HCl + HNO3 (low pH)

where substituting Na for one of the Hydrogens, produces the author's reaction, which may, indeed, be the intermediate and the obserable reaction in a neutral to high pH conditions (like moist NaOH).

AJKOER - 8-2-2013 at 06:42

Here is a source (http://nitrogen.atomistry.com/nitryl_chloride.html ) that claims NO2Cl is, in fact, NOT prepared by the direct methods and via AgNO3 per more recent studies. To quote:

"Nitryl Chloride, NO2Cl, was stated to have been obtained by the action of nitrogen tetroxide on chlorine or hydrogen chloride, and by the action of chlorine on silver nitrate. Similarly, nitryl bromide, NO2Br, was considered to be the product of the action of bromine on nitrogen tetroxide. Later investigations, however, appeared to disprove the formation of these halogen compounds by the above methods. More recently, it is claimed that nitryl chloride is formed when nitric acid reacts with phosphorus oxychloride, and nitryl bromide by passing nitrogen tetroxide and bromine vapour over a catalyst of calcined lime heated to 200°-250° C."

Theoretic - 25-3-2013 at 17:40

funny that a source seems to disclaim the formation of nitryl chloride from NO2 and chlorine
because i have an old soviet chemistry book tha claims this reaction happens *slowly* - now this seems oddly specific

if this reaction that you posted really does occur it seems to be the basis:
NO2Cl(g) + NO(g) <⇄> NOCl(g) + NO2(g)
it seems quite likely that nitric oxide will use its radical reactivity to take either an oxygen or a chlorine from the nitryl chloride, and the reaction energy is probably low, making it reversible

what is really interesting is the reaction of NOCl's formation directly from the elements! i have read that reacton in a chemistry encyclopedia before, but cannot recall what that encyclopedia was

You seem to have a reference however! Would you care to provide it?

another interesting reaction from the same book was a method for making nitrosyl chloride:
NaNO3(s) + Cl2(g) <⇄> NOCl(g) + NaClO2(s)
holy b@llsack!! do you see it!? it produces sodium chlorite, an advance oxychlorine species, without the wasteful disproportionation that is normally used in industry
and knowing that
2NOCl <⇄> Cl2 + 2NO
2NO + O2 => 2NO2
and that NO2 will react with chlorides to produce NOCl and nitrates (using its ionic dissociation N2O4 <⇄> NO+ + NO3-), this seems to be a way to produce chlorite from chloride and air

I'm sure you'd need to input energy somewhere along this sequence, but it seems more efficient than using electricity to oxidize chlorine and then disproportionate...
in fact (thermodynamically) it would even be favorable to turn chloride into perchlorate using oxygen

AJKOER - 28-3-2013 at 13:31

Quote: Originally posted by Theoretic

......

what is really interesting is the reaction of NOCl's formation directly from the elements! i have read that reacton in a chemistry encyclopedia before, but cannot recall what that encyclopedia was

You seem to have a reference however! Would you care to provide it?

Here is another source other than Wikipedia, but it may be only repeating Wikipedia, see http://site.iugaza.edu.ps/bqeshta/files/2010/02/94398_16.pdf . To quote:

"Also, nitrosyl chloride can be synthesized from its elements by heating nitrogen, oxygen and chlorine gas at 400°C:

N2 + O2 + Cl2 → 2ClNO "

However, this reaction, in my opinion and the author of the patent I cited on the direct union of Chlorine and Oxygen, is that Ozone is a likely intermediary, leading to an active Oxygen radical and the formation of NO (and then NOCl) and some ClO2. Also, active Chlorine (along with CH and OH radicals) is a suspected catalyst to Ozone formation.
--------------------------------------------------------------

Now making Chlorites out of the air, this is already doable as the cited patent on using polarized uv on Cl2 and O2 to form ClO2 with a reported yield of around 8% can do this, as per the reaction employing the created ClO2 (see attached file):

2Cl02 + H202 + 2NaOH --> 2NaClO2+ 2H20 + 02
---------------------------------------------------------------

What I think would be interesting would be to ignite the following gas mixture in a confined space. One possible product path:

(4 NH3 + 3 H2 ) + (5 Cl2 + 5 O2) --> 6 HCl + 4 NOCl + 6 H2O

although I would expect only small amounts of NOCl. The pressure from the detonation and heat would be contributing factors for success.

Some possible reactions:

4 NH3 + 4 Cl2 --> 4 NH2Cl + 4 HCl (see http://pubs.acs.org/doi/abs/10.1021/ja01644a010 possible explosion)

4 NO + 2 Cl2 -Heat-> 4 NOCl

H2 + Cl2 --> 2 HCl + Heat

2 H2 + O2 -->2 H2O + Heat

And speculation based on the combustion of NH3 under pressure in the presence of Pt (none here):

4 NH2Cl + 4 O2 --?-Pressure/Heat-?--> 4 NO + 4 H2O + 2 Cl2

Imply net reaction:

4 NH3 + 5 Cl2 + 5 O2 + 3 H2 --> 6 HCl + 4 NOCl + 6 H2O

Other reaction:

NH2Cl + Cl2 --> NHCl2 + HCl

Attachment: production-of-sodium-chlorite.pdf (1.5MB)
This file has been downloaded 730 times

[Edited on 29-3-2013 by AJKOER]

woelen - 28-3-2013 at 23:37

@Theoretic: All these reactions have no practical meaning at all.

NO2 + Cl2 may react "slowly", but what is "slowly"? One atom per hour? One atom per second? I can say though, from an experiment I have done, that NO2 and Cl2 do not react with each other at any visible rate. I mixed the dried gases and the mix remained the same dirty brown color, even after hours. I used excess Cl2 and if a noticeable reaction occurred, then the brown color would disappear and the green of Cl2 would remain. NO2Cl is colorless.

Formation of ONCl from the elements indeed is possible. I made NO (not from the elements, but from nitrites and acid, while shaking with water). When Cl2 is added to the NO, then an orange gas is formed at once. This reaction is fast. The orange gas is ONCl. NO can be formed from the elements, but it requires a lot of energy, a high discharge current through N2+O2 mix is required. WHen Cl2 is added afterwards, then ONCl may be formed. But do not expect good yields. NO also reacts with remaining O2 to NO2 and that does not react with Cl2 at an appreciable rate.

Next, the reaction of Cl2 with nitrate. Do you really believe that? Maybe with some specal more unstable nitrates of specific metals, but I even doubt that. NaNO3 will not react with Cl2 at any appreciable rate. I'm sure that if very advanced measurement techniques are used, that a few ClO2(-), ClO3(-) and ONCl molecules can be detected, but not more than that. No practical meaning at all.

AndersHoveland - 29-3-2013 at 01:52

Quote: Originally posted by woelen

NaNO3 will not react with Cl2 at any appreciable rate.

Generally we would not expect any reaction.

Though there might be some very small equilibrium in aqueous solution. We do know there is some equilibrium of NaNO3 in concentrated hydrochloric acid, and we also know there is some dissassociation of chlorine in water.

I did, however, recently come upon this intriguing reference:

"Also, nitrosyl chloride is produced by the action of chlorine on sodium nitrate...

NaNO3 + Cl2 --> ClNO + NaClO2 "

Handbook of Inorganic Chemicals, Pradyot Patnaik
http://site.iugaza.edu.ps/bqeshta/files/2010/02/94398_16.pdf

I have not tested the reaction, and am not sure how reliable the source is. But it would be very interesting if true. I would imagine the NaNO3 solution would have to be completely saturated with chlorine.

That would open up interesting possibilities, because after all the nitrosyl chloride had been evolved, further addition of chlorine would presumably react with the remaining chlorite and cause chlorine dioxide to be evolved, since:

2 NaClO2 + Cl2 --> 2 NaCl + 2 ClO2 (this is a well-known reaction commonly used in water treatment)

US patent 3,754,079 mentions that nitrosyl chloride can react with chlorates to form chlorine dioxide.

[Edited on 29-3-2013 by AndersHoveland]

AJKOER - 29-3-2013 at 07:37

Quote: Originally posted by AndersHoveland

Quote: Originally posted by woelen

NaNO3 will not react with Cl2 at any appreciable rate.

Actually, I could envision the reaction:

NaNO3 + Cl2 --> ClNO + NaClO2

proceeding, but not precisely as indicated, with a low yield at high temperatures as follows:

1. Thermal decomposition of NaNO3 at over 700 C (see https://docs.google.com/viewer?a=v&q=cache:xo8goXDEh1UJ:... ) perhaps as follows:

2 NaNO3 --> Na2O + 3/2 O2 (g) + 2 NO (g)

2. Next, NOCl is formed upon cooling by the action of Cl2 on NO:

2 NO + Cl2 --> 2 NOCl

3. The formation of Cl2O (per a low yielding commercial process) by passing steam, Cl2 over heated NaOH (or Na2CO3):

Na2O + H2O (g) + 2 Cl2 --> 2 NaCl + Cl2O (g) + H2O (g)

4. Some chlorite could then be formed as follows based on the known reactions:

NaCl + HOCl <--> NaOH + Cl2

and as:

NaOH + HOCl --> NaClO + H2O
NaClO + HOCl --> NaClO2 + HCl

So the implied net reaction is:

NaCl + 3 HOCl --> NaClO2 + Cl2 + HCl + H2O

and as 3 HOCl --> 3/2 H2O + 3/2 Cl2O, upon removing water implies:

NaCl + 3/2 Cl2O + 1/2 H2O --> NaClO2 + Cl2 + HCl

or:

2 NaCl + 3 Cl2O + H2O --> 2 NaClO2 + 2 Cl2 + 2 HCl

So, bottom line I can envision a reaction producing problematically the indicated products occurring by heating the NaNO3 to decomposition, and then allowing steam and chlorine to react with the decompositon products. However, the necessary procedure to form the indicated products requires carefully planning given the varying temperatures required for NO formation, which is above the decomposition levels for NOCl and Cl2O. So perhaps first decompose the NaNO3 at 700 C in an opened ended tube (a sealed chamber may be a possible explosion hazard), allow the exit gases (including NO) to cool and react with dry Cl2 forming NOCl. Then add steam and Cl2 to the mildly heated decomposed NaNO3 to form chlorite, ..etc., in a sealed tube.

I would, however, not recommend this procedure.

[Edited on 29-3-2013 by AJKOER]

[Edited on 30-3-2013 by AJKOER]

AndersHoveland - 29-3-2013 at 17:21

NaNO3 467 kJ/mol
NaClO2 307 kJ/mol
NOCl 52 kJ/mol

A quick look at the heats of formation suggests the reaction would not be favorable. This does not necessarily mean the reaction would not proceed. It could be an endothermic reaction, or there could be another important side reaction creating other products that would push the equilibrium.

•

DoctorZET - 15-4-2014 at 04:51

the reaction between N2O4 and Cl2 should be catalised by a intense blue-UV light, because Cl ions are formed.

AJKOER - 10-4-2017 at 06:29

Quote: Originally posted by AndersHoveland

I have a question about nitryl chloride, NO2Cl.
Can it be prepared by direct combination of nitrogen dioxide with chlorine?

How stable is it? Is there an equilibrium under normal conditions with NO2 and Cl2 ? Or is NO2Cl stable at ambient temperature?

Does the chemistry of NO2Cl have any similarities to nitrosyl chloride, NOCl ?

.....[Edited on 1-2-2013 by AndersHoveland]

It just occurred to me (a bit slow apparently, it took over 4 years) given the ease of the H2/Cl2/Red Light in producing monoatomic chlorine to engage in the H2/Cl2 chain reaction (absence any O2 or water vapor, which introduce a termination step in the reaction chain), what about the photolysis of NO2/Cl2 or NO/Cl2?

Apparently, the action of light on the latter is a path in use for organic synthesis where NO/Cl2 is dissolved in an organic and irradiated as an, in situ created, substitute for NOCl.

Interesting, my ebook reference, "Preparative Organic Photochemistry" by Alexander Schönberg, pages 263 to 264, cites the use of a catalyst (called "Kali-Perl-Katalysator-Alt", see https://books.google.com/books?id=HXbtCAAAQBAJ&pg=PA263&... ), applied to the gases pre irradiation consisting of Al2O3 (10%), SiO2 a little under 90% and Cr2O3 (0.15%).

Testing would be needed to confirm the use of NO2/Cl2 in a similar path.

[Edited on 10-4-2017 by AJKOER]

bluamine - 11-4-2017 at 10:34

Quote: Originally posted by AJKOER

An interesting comment is:

"Reaction with sodium hydroxide forms sodium nitrite and sodium hypochlorite:

2NaOH + NO2Cl → NaNO2 + NaOCl + H2O "

which suggests a convenient path to Nitrite salts and chloride-free hypochlorite. An important note:

[Edited on 3-2-2013 by AJKOER]

If i was you, i would recommend bubbling chlorine through a sodium carbonate solution which produces Cl2O with CO2. These two gases must be bubbled through a Ca(OH)2 suspension so we can obtain CaCO3 (percipitates) & Ca(OCl)2, which can be reacted with sodium hydroxide to produce calcium hydroxide & a chloride free sodium hypochlorite solution. Now we all know calcium hydroxide is not really insoluble in water, it's just very slighly soluble, so the solution must contain a little bit of calcium hydroxide, i would suggest neutralizing it with a diluted weak acid! i don't know how important the purity must be in both of these two cases though.. also, i think freezing the solution may cause some loss (by percipitating some hypochlorite produt)
What do you think guys?

[Edited on 11-4-2017 by bluamine]

clearly_not_atara - 11-4-2017 at 13:50

This thread reminds me that I was trying to estimate the feasibility of making chlorosulfonic acid by passing HCl through sulfuric acid containing sodium pyrosulfate. It's also possible that phosphoric acid could be used which would be nice as it's easier to get than conc H2SO4.

Anyway I think that imply adding a nitrate salt to a mixture of sulfuric and chlorosulfuric acids should generate significant amounts of NO2Cl. Nitric acid is formed in situ and reacts.

[Edited on 11-4-2017 by clearly_not_atara]

AJKOER - 2-8-2018 at 12:13

Per Wikipedia again:

"NOCl and cyclohexane react photochemically to give cyclohexanone oxime hydrochloride. This process exploits the tendency of NOCl to undergo photodissociation into NO and Cl radicals."

So, NOCl + hv = .NO + .Cl

So, working with dry .NO and Cl2 (and possibly a good idea to limit oxygen presence also based on its interruption of the reaction chain during the photolysis of H2 and Cl2), I would similarly expect:

Cl2 + hv --> .Cl + .Cl

.Cl + .NO --> NOCl

NOCl + hv = .NO + .Cl

but the equilibrium amount of NOCl created could be low from photodissociation.

[Edited on 2-8-2018 by AJKOER]

clearly_not_atara - 2-8-2018 at 12:47

That's nitrosyl chloride, not nitryl chloride.

Also, the method I posted above, w.r.t. making chlorosulfonic acid, probably does not work, because disulfuric acid is much stronger than I had estimated at first. The acidity of H2S2O7 is comparable to CF3SO3H; the pKa for the second deprotonation is not available, but I don't have my hopes up, really. Chlorosulfonic acid is similarly strong. The reaction of NO3- and ClSO3H might work, but I don't have my hopes up; N2O5 production is also a possibility, and not a friendly one.

[Edited on 2-8-2018 by clearly_not_atara]