Sciencemadness Discussion Board

Thermal Decomposition of TCCA

SgtAltek - 12-8-2017 at 21:36

Hey all! I was wondering what the products of the thermal decomposition of TCCA would be. I was thinking NCl3, but I'm not really sure. I've also heard it can decompose to Cl2 and Cyanuric Acid.

Besides that, are there any other interesting uses for TCCA besides a Cl2 generator with HCl? I use that quite a lot to produce iodine from KI haha. Thanks.

CRUSTY - 13-8-2017 at 04:11

Google is your friend. :)

The MSDS attached lists the thermal decomposition products as chlorine, nitrogen, nitrogen trichloride, cyanogen chloride, "oxides of carbon", and phosgene.

Cyanuric acid however, is a result of exposure to water or moisture, not thermal decomposition.

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VSEPR_VOID - 2-9-2017 at 19:51

Wow, that does not sound like something we want decomposing. Considering how much labor goes into preventing terrorists from making chemical weapons, imagine the damage that could be done with phosgene generated from TCCA. Just condense the phsogene with cold water and store it.

Assured Fish - 2-9-2017 at 20:13
Quote:

Just condense the phsogene with cold water and store it

Are you insane, phosgene for one boils at 8*C making condensation with even ice water, extremely difficult.
Then the idea of storing it, i doubt anyone would want to store it given that it exothermically decomposes on contact with water, which would drive it to evaporate and build up pressure inside any container you have put it in. This would mean that you would need to dry the phosgene before storage and likely store it inside an ampule.
Remember that one of the decomposition products of TCCA is H2O which makes drying an absolute necessity.

In fact phosgene is likely to only be a minor byproduct of the decomposition of TCCA which would by itself make the idea of generating phosgene from from TCCA futile.

A better option would be to simply avoid decomposing TCCA and in the case where you needed phosgene for preparing thionyl chloride or whatever, then it would be a far better idea (albeit and insane idea) to prepare it via the oxidation of chloroform.

ninhydric1 - 2-9-2017 at 21:39

And then there's chlorine and cyanogen chloride. Chlorine I might work with, but no way in h*** will I work with cyanogen chloride. Only if I had a respirator, oxygen tank, cyanide antidote kit, a fume hood with maximum venting ability, and quick exit from the lab would I work with cyanogen chloride.

nezza - 3-9-2017 at 00:54

And of course NCl3 is another really benign agent. It explodes if you look at it wrong and has maimed some famous chemists in the past.

unionised - 3-9-2017 at 04:10

The thermal decomposition products listed in MSDS are usually a guess, rather then the result of experiment.
I doubt the yield of phosgene is any good.

VSEPR_VOID - 3-9-2017 at 11:29

Quote: Originally posted by Assured Fish  

Quote:

Just condense the phsogene with cold water and store it

Are you insane, phosgene for one boils at 8*C making condensation with even ice water, extremely difficult.
Then the idea of storing it, i doubt anyone would want to store it given that it exothermically decomposes on contact with water, which would drive it to evaporate and build up pressure inside any container you have put it in. This would mean that you would need to dry the phosgene before storage and likely store it inside an ampule.
Remember that one of the decomposition products of TCCA is H2O which makes drying an absolute necessity.

In fact phosgene is likely to only be a minor byproduct of the decomposition of TCCA which would by itself make the idea of generating phosgene from from TCCA futile.

A better option would be to simply avoid decomposing TCCA and in the case where you needed phosgene for preparing thionyl chloride or whatever, then it would be a far better idea (albeit and insane idea) to prepare it via the oxidation of chloroform.


My mistake, and I suppose that is a win for Humanity in general. I should have figured that if Phosgene was so easy to produce and store it would find more of purpose in contemporary chemical weapons. I redact my earlier claim.