Sciencemadness Discussion Board

OC(NN)2CO

madscientist - 31-8-2002 at 16:32

I would think that OC(NN)2CO would be an excellent energetic material. It would have the following structure:

O=C(N=N)2C=O

I think the best route to preparing it would be adding liquid bromine to urea, or passing chlorine gas over urea. I tried something else today, however. I mixed six grams of CO(NH2)2 and seven grams of Ca(OCl)2. I retreated indoors for fear that phosgene (COCl2) might be liberated. I returned outside ten minutes later to find an off-white mass that had clearly been molten, giving off large volumes of gas, and then had solidified. I added 10mL of water, and it foamed a little. More tales of my pursuit of OC(NN)2CO are surely on the way.

madscientist - 31-8-2002 at 16:53

Here's the equations.

2CO(NH2)2 + 2Ca(OCl)2 ----> OC(NN)2CO + 4H2O + 2CaCl2

2CO(NH2)2 + 4Br2 ----> 2CO(NHBr)2 + 4HBr ----> OC(NN)2CO + 8HBr

2CO(NH2)2 + 4Cl2 ----> 2CO(NHCl2 + 4HCl ----> OC(NN)2CO + 8HCl

madscientist - 31-8-2002 at 20:23

I am getting very angry about not being able to edit posts!

I just realized that I made a goof when typing up the first equation. It should be:

2CO(NH2)2 + 4Ca(OCl)2 ----> OC(NN)2CO + 4H2O + 4CaCl2

I am now strongly suspecting that phosgene may have been liberated. Noone try this unless you really think you are ready to deal with phosgene, I don't want anyone killing themselves. I'll try to resolve this myself. :) Does anyone have any particularily brilliant idea for detecting phosgene? This is how it could be formed.

2CO(NH2)2 + 4Ca(OCl)2 ----> 2COCl2 + 2CaOCl2 + 2Ca(OH)2 + 2N2 + 2H2O

That theory was backed up by my heating of some of the white solid with my lighter. It fizzled slowly, and I could smell chlorine.

If I get around to it, I'll put some insects in a flask, mix urea and calcium hypochlorite in another, put a tube in a rubber stopper and jam it in the mouth of the flask with the chemicals, then put the other end of the tube in the flask containing insects. Then I'll back way the hell off - I don't want to suffer the fate that the insects will probably face.

madscientist - 31-8-2002 at 20:26

Argh! Another brain fart! My correction on the equation that I thought for a moment was unbalanced but actually was balanced was incorrect! The original equation WAS balanced.

I must figure out what is wrong with the board software.

Test for phosgene

Ramiel - 31-8-2002 at 22:13

No, the insect one wouldn't work...
Insects generally have different respiratory systems to mammals, they have pores on thier exosceletons i believe, which allows them to breathe. So if you wanted to test for phosgene; you would have to use a mammal. Or you could inhale it... if you get red and yellow angry blisters on your trachea, followed by coughing fits and bleeding lungs, it's probably only chlorine...

I would strongly suggest investing in one of these phosgene dosometers if you are serious about that experiment.

madscientist - 1-9-2002 at 07:37

Here's the best idea for a phosgene test that I have so far. I'll pass the produced through a metal tube that is being heated by a propane burner. If a yellowish gas is emitted from the tube, then it'll be clear this is happening.

COCl2 ----> CO + Cl2

Rhadon - 1-9-2002 at 10:07

The phosgene test-papers are based on a reaction of phosgene with 4-(dimethylamino)benzaldehyde and either diethyl-, dimethyl- or diphenylamine. If phosgene is present, the color changes to orange.

Another test would be detecting the characteristic (foul, sweetish) smell in the air. Phosgene can already be smelled in very low concentrations, but only in concentrations in which it is toxic. Tough, I doubt that you'll be able to do tests with it without even getting a little bit of it into your nose (unless you wear a mask).

According to "The War Gases Chemistry and Analysis", one single ml of gaseous phosgene placed in a 500 ml flask that it filled with ordinary air can still be smelled after 15 days (this was to test how fast phosgene's hydrolysis takes place). And if they were able to notice the smelled of phosgene, they must have smelled it, presumably without taking harm from it. Anyway, I didn't want to try that.

madscientist - 1-9-2002 at 16:12

I'm fairly convinced that the reaction between 6g of urea and 7g of calcium hypochlorite is producing phosgene. I did another experiment with it today. I mixed 6g of urea with 7g of calcium hypochlorite in a flask, and quickly stoppered it with a rubber stopper that had a thin rubber tube running through it. I placed the other end of the tube in a flask that was in a salt/ice bath. I then backed way the hell off. After about thirty seconds the reaction began at a visible rate, and rapidly accelerated. The reaction flask and the condensation flask quickly filled up with a white gas. The white gas was almost immediately pouring out of the condensation flask and running along the ground - to be expected, considering that the condensation flask was only 250mL. I waited until all traces of the whitish gas were no longer to be seen before approaching the setup. I took a deep breath, then marched forward and dropped an ant into the condensation vessel (there was maybe 2mL of liquid in it). The ant flailed around for a short period of time, then curled up and died.

raistlin - 1-9-2002 at 18:13

Is it possible that it did of more less drowning?

raistlin - 1-9-2002 at 18:14

I had meant to say "Is it possible that it could have died of drowning?"

madscientist - 1-9-2002 at 19:10

Nope, the ant never came in contact with the liquid while it was alive. In a 250mL flask, 2mL of a liquid is not going to appear to be that much. I tilted the flask, and tossed the ant in, which seemed to be flailing wildly trying to avoid sliding into the liquid immediately before it died.

New Venture?

Ramiel - 2-9-2002 at 05:38

You could very well start up a new buisiness venture by the sounds of things... :)

Rhadon - 2-9-2002 at 09:48

Quote:
Is it possible that it could have died of drowning?

As far is I know, all animals are able to swim, except for monkeys (and humans). At least in water. And even if it sinks beneath the surface of the liquid, it should take a significant time for the animal to die from mere lack of oxygen.

Madscientist, perhaps this reaction will serve you as a test for phosgene:

in acetone solution
COCl2 + 2 NaI --> CO + I2 + 2 NaCl

Thus, leading that gas through a solution of sodium iodide in acetone should tell you whether it is phosgene or not.

raistlin - 2-9-2002 at 14:42

No, it would only take a few seconds for an ant to die of drowning, because of the fact that they breath constantly throught small, pore-like openings on the sides of their body. I would think that if it was submerged for only a matter of a few seconds, the ants respiration would cease... The way Madscientist worded it made me think that it had actually been placed into the liquid.

Raistlin

Rhadon - 2-9-2002 at 15:56

Ants have no lungs, but they do have blood. So if there is no access to oxygen from the atmosphere, there will still be some dissolved in the blood.

When ants are in their "homes" down in the earth, they aren't supplied with oxygen as well as above the surface. I suppose that they are adapted to this and have low needs of oxygen.
Quote:
No, it would only take a few seconds for an ant to die of drowning (...)

This is not the case, perhaps because their brains are less easily affected by lack of oxygen than that of mammals. Here is what someone found out when experimenting with drowning them.

madscientist - 4-9-2002 at 13:50

Another possibility:

2CO(NH2)2 + Ca(OCl)2 ----> CaCl2 + 2N2H4 + 2CO2

Madog - 4-9-2002 at 18:00

today i gassed an ant with Chlorine. it took under a second and it was on its back curled up.

Rhadon - 4-9-2002 at 18:31

Perhaps the experiments should be carried out on more resistant animals - such as spiders (they're nasty anyway, it doesn't matter if there are some less...). They may be harder to find than ants, but it might be worth the effort.

I once caught a relatively large one, placed it in a marmalade jar that had two holes in the lid. In one, there was introduced a pipe that served for inducing different substances.
I started with NH3 gas. The spider took notice of it, but wasn't too affected. Next was (liquid) acrolein, which didn't seem to harm it at all (perhaps it was already too pampered with NH3 ;)). This surprised me somewhat, since the affect of acrolein on humans is significantly higher than that of NH3. Anyway, I continued my experiments with chlorine. The spider got quite agile in contact with it, but this state didn't last long - after some seconds it died, bot not instantly.

Does anyone know what kind of respiration spiders have? Perhaps they are suitable for tests on phosgene, but I'm afraid they're not.

Madog - 4-9-2002 at 18:57

the Cl made it high?!!?!

that is crazy. i cant believe the damn thing lived. well, im not realy into cruely killing animals so im not gona do any tests.

Rhadon - 5-9-2002 at 06:00

Perhaps what I said wasn't clear. I wanted to say:

The Cl2 made it run in its glass for a short time, until it died.

Well, usually I'm also not the guy for cruel tests on animals, with the exception of spiders.

...Nothing wrong with spiders

Ramiel - 6-9-2002 at 00:27

Madog - 6-9-2002 at 11:34

i probaly wouldnt do it on anything other than a worm, ant, or small insects. i think spiders are cool. i would never do it on a mamal, thats just sick

PHILOU Zrealone - 10-9-2002 at 13:25

Indeed MadScientist, there is a patented process to make hydrazine from urea and hypochlorite!

The reaction is something like:
NH2-CO-NH2 + NaOCl --> NaCl + NH2-CO2-NH2 --> NaCl + NH2-NH2 + CO2

But things are not so simple and another reaction happens immediately between the hydrazine and the NaOCl
NH2-NH2 + 2NaOCl --> 2NaCl + N2 + 2H2O.

There is some ways to get to tetraazacyclohexane but they are very much more difficult than what you propose...as you had the impression the compound is quite unstable and goes fast into decomposition products...reactants are critical and may catalyse decomposition!

2NH2-NH2 + 2Cl2C=O --> O=C(NH-NH)2C=O + 4HCl + linear polymers
O=C(NH-NH)2C=O mild oxydation --> O=C(N=N)2C=O + 2H2O

Cl2C=O may form carbonic esters with alcohols!
It will free I2 from NaI; but Cl2 will aswel do such reaction.

Cl-CO2H may be a good way too with hydrazine; CI2Cl2 may be also good!

PH Z

Well

Boob Raider - 15-10-2002 at 19:05

Madscientst ..... if urea is treated with a hypochlorite ...... N2H4, CO2 and NaCl are the major products like Philou said. Although if you want to use this as a method of N2H4 prep. .... you need to add a viscolizer (gelling agent) like starch, agar, gelatine or even glycerol to protect the N2H4 from the free OCl-. Agar and gelatine seem to be most effictive.

Marvin - 29-10-2002 at 16:53

Rather wanting to avoid phosgene, Ive found an alternative to PH Z's method.

The cyclic compound O=C(NH-NH)2C=O is called p-urazine, which might help anyone searching for information.

It can be obtained in good yeild by semicarbazide + hypobromite (and presumably hypochlorite, but it doesnt say). Unfortunatly I dont know the conditions it works well at, I do know the conditions it doesnt work at becuase it produces hydrazodicarbonamide instead.

The references for making p-urazine are, I think,
Linch, F. W. Proc. Chem. Soc. 28,144
J. Chem. Soc. 101, 1755-8 (1912)
C. A. 7, 591 (9)

With some luck someone will have access to these. Making semicarbazide can probably be done directly from chloramine and urea.

Nick F - 30-10-2002 at 04:37

I have some semicarbazide hydrochloride, and obviously I can get NaOCl bleach. I have some Ca(OCl)2 too, but all the Ca(OH)2 in it makes filtering etc more difficult.
Semicarbazide is made by reacting monochlorourea (normally as its sodium salt) with ammonia, to form semicarbazide and NaCl, and it is then ppted as a salt by adding an acid, normally HCl or H2SO4.
But unfortunately I don't have access to those references :( If anyone does, please tell me how to do it! I'll have a search for info too.

Marvin - 31-10-2002 at 18:54

Yikes, monochlorourea is stable!
Id have thought the intramolecular reaction would be intrinsically much faster than the intermolecular one producing semicarbazide. Strange. Id be interested in more info on that one if anyone has it.

It can also be produced by reduction, eg electrolytically, or with zinc/acid of nitrourea. A prep that will probably find favour here. Not to mention not requiring gallons of dilute bleach....

Nick F - 1-11-2002 at 04:01

I got nothing when I tried Zn/HCl reduction of nitrourea, the electrolytic method looks much more promising but I've never tried it. I can't see any reason why you couldn't fill your cell with the right amount of H2O, and simply dump into it the H2SO4/nitrourea mixture formed when making NU from UN and H2SO4. IIRC the NU solution is acidified with H2SO4 anyway. But maybe it'd be too acidic with this method... but it would save you the hassle of filtering, drying etc.

PHILOU Zrealone - 13-3-2003 at 05:37

By CI2Cl2 I meant I2CCl2 thus diiododichloromethane and not tetraiodoethylene....hard to discriminate I from l!


By the way:

HO-C(N4)C-OH <-H2- O=C(-N=N-)2C=O

IrC - 8-11-2010 at 21:41

There is a fairly easy test for phosgene using a home made test paper. "Paper soaked in alcoholic solution containing 10% of a mixture of equal parts of p-dimethylaminobenzaldehyde and colorless diphenyamine, then dried, will turn from yellow to deep orange in the presence of approximately the maximum allowable concentration of phosgene." The permissible exposure limit for phosgene is 0.1 parts per million (p.p.m.), so this is a fairly sensitive test. This test paper is fairly inexpensive to make: p-dimethylaminobenzaldehyde --Sigma # D 2004; 25 g., $8.85; diphenyamine--Sigma # D 2385; 5 g., $13.50, 25 g. $50.35.

The above is from the following link.

http://www.ars.usda.gov/Main/docs.htm?docid=3594&page=6

Phosgene generated from old Chloroform is something not well remembered in the last 50 or more years. I think in lieu of all the insects and small furry mammals being harmed for tests unlikely to tell you anything useful about the presence of phosgene (or it's level in ppm), you should just make this simple and reliable test paper. I do not think it beyond the amateur to calibrate the paper based upon color. Fairly simple circuitry exists which could drive a meter by detecting and measuring the color change. Also not much of a stretch to use an opamp comparator to fire up a nice loud piezoelectric alert when the level goes above a preset, which would be simply adjusted by turning a trimmer potentiometer on the circuit board.

This information is presented in the interest of saving countless lives and suffering on behalf of all small creatures everywhere no matter how ugly they are.


[Edited on 11-9-2010 by IrC]

Mr. Wizard - 9-11-2010 at 07:21

When cleaning up bird lime from concrete under an outdoor cage, I used sodium hypochlorite bleach solution. Since bird lime contains urea and other similar compounds I always though it produced chlorine and chloramine. It would foam up and produce a very strong chlorine smell. I would always move the cage and birds away, and never had a problem. It does an excellent job of cleaning the concrete. I never thought about phosgene.