Sciencemadness Discussion Board - CDIC and the most incredible lachrymator ever

CDIC and the most incredible lachrymator ever

Rhodanide - 27-10-2017 at 17:58

Alright - another day, another strange event.
I started to make some Sodium Dichloroisocyanurate for it's complex with copper. My plan was to react TCCA with a solution of Sodium Bicarbonate until no more bubbles of CO2 and Chlorine would be given off. (I was outside, upwind) About five senconds after I added the first spatula of TCCA, an absolutely incredible vapor hit me. It smelled like chlorine, but there was absolutely no chlorine detectable even when I later repeated this in different conditions in front of a stark white background, no color was seen. It burned my eyes far worse than Chloropicrin or Chloroacetone, made me cough so hard that I almost threw up, and still causes irritation to my chest hours later. It smelled basically like Cl, but with a different twist to it. It was more metallic, more artificial and less "sweet" than Cl. I've dealt with a fair share of Chlorine gas, and this WAS NOT IT. None of my reagents were impure or contaminated in any major way. I did however end up making the Copper Dichloroisocyanurate complex, which turned out quite nice. However, the smell still is lingering. I washed the precipitate once with water, and still the smell remains. Please tell me what it was, or at least what you think it was. It was honestly one of the most frightening situations I've encountered in Chemistry.

The precipitate v v v v

[Edited on 28-10-2017 by Tetra]

BlackDragon2712 - 28-10-2017 at 01:39

Beautiful color, nicely done!... maybe the vapor could have carried some particles of sodium dichlroisocyanurate? It says in here that it has some properties as a lachrymator so it could be one possibility.
http://www.google.ch/patents/US3035057

Melgar - 28-10-2017 at 03:23

I doubt it was particles of any solid. You typically feel those as a stinging in your nose or throat, and they wouldn't reach your chest. I feel like you're describing chloramine:

https://en.wikipedia.org/wiki/Chloramine

This is the stuff that results from mixing bleach and ammonia, and is the reason you're not supposed to mix the two. In low concentrations, it smells like swimming pools, where it forms from the gradual breakdown of protein by chlorine. It meets all your criteria though, and like you described, it smells a lot like chlorine, but is distinctly different, and colorless. TCCA is weakly acidic, and is unstable in bases and releases chlorine in the presence of strong acids. I know it decomposes initially into urea derivatives, which can presumably hydrolyze into ammonia derivatives like chloramine.

LearnedAmateur - 28-10-2017 at 03:38

There's also mention of a powerful lachrymator being produced during a very similar procedure in this thread. Maybe it can help you to find out what was responsible - if your NaHCO3 solution had some carbonate in it, then there is OH- present in equilibrium (CO3(-2) + H2O <-> HCO3- + OH-) which could facilitate a hydrolysis reaction. If you test your NaHCO3 solution then it should have a pH just above 8, whereas Na2CO3 will be around 10 so somewhere between those values will indicate that you probably have some contamination. NaHCO3 begins to decompose above 50C so if you've boiled down your bicarbonate solution prior to this reaction then there will be a significant amount of the carbonate.

http://www.sciencemadness.org/talk/viewthread.php?tid=18953

Melgar - 28-10-2017 at 04:10

Quote: Originally posted by LearnedAmateur

There's also mention of a powerful lachrymator being produced during a very similar procedure in this thread. Maybe it can help you to find out what was responsible - if your NaHCO3 solution had some carbonate in it, then there is OH- present in equilibrium (CO3(-2) + H2O <-> HCO3- + OH-) which could facilitate a hydrolysis reaction. If you test your NaHCO3 solution then it should have a pH just above 8, whereas Na2CO3 will be around 10 so somewhere between those values will indicate that you probably have some contamination. NaHCO3 begins to decompose above 50C so if you've boiled down your bicarbonate solution prior to this reaction then there will be a significant amount of the carbonate.

http://www.sciencemadness.org/talk/viewthread.php?tid=18953

I read that thread. To me, the explosion sounds like a gas-phase oxidation by chlorine, the chlorine having been produced by decomposition of TCCA. I had that happen once when some aluminum got into my chlorine generator (that used TCCA and HCl) and reacted with the HCl to produce hydrogen. The explosion blew the glass stopper out of the neck of the flask, which hit the underside of the cupboard that was above it and cracked into several pieces. In that thread, OP describes boiling a TCCA solution, and I'm curious what the vessel was made of. Glass wouldn't have reacted, but stainless steel certainly would have. Or it could have been evolved ammonia that reacted, producing chloramine, which seems like the likely culprit in this thread as well.

LearnedAmateur - 28-10-2017 at 04:41

I've been suspecting chloramines as the lachrymatory agents, not just NH2Cl but those of the amide hydrolysis products (Chlorourea? Chlorobiuret?).

Bahamuth mentioned a beaker and watchglass in the linked thread so I don't think any metals were involved, considering the unstable nature of TCCA as it is. I doubt this reaction would usually create an explosive mixture, but the liberation of explosive chlorine-based gases into a confined space, heavier than air also, enabled it to reach sufficient concentration to detonate under those conditions.

Rhodanide - 28-10-2017 at 06:48

MAJOR UPDATE: When I filtered the mixture, washed with water twice, the odor faded substantially. HOWEVER - When I washed it with Isopropyl alcohol and left it for an hour, a violent reaction seemed to take place, releasing heat, irritating vapors, and warm alcohol vapor! My housemate was much less than pleased. What the hell happened? I'm just glad I put another plastic funnel upside down over the one in the process of filtering, saved me a ton of clean up!

Melgar - 28-10-2017 at 07:35

Well, I see you've just been introduced to a variant of the haloform reaction. Isopropanol is oxidized into acetone, and we all know what happens when you mix acetone and bleach. Under acidic conditions, the major product would be chloroacetone, which you said you were familiar with already. Of course, the heat generated would have caused a lot of the unreacted isopropanol to boil or evaporate.

DFliyerz - 31-10-2017 at 21:10

I certainly remember this smell from when I made that copper salt; it makes me want to vomit just thinking about it!

DFliyerz - 26-2-2018 at 23:33

A few months later and I think I've figured out that it's either HClO or some decomposition product of HClO, since a bleach solution used to clean glassware with a small amount of acidic residue left on it produced an almost identical smell.

zed - 1-3-2018 at 15:50

CDIC? TriChloro?

Yup! Bad stuff. But an effective reagent. Better stock up, while it's still on the market.

My eyes burn, just from examining the closed bottles on display at my local hardware outlet.

It's the kind of thing, I handle with caution. In a Hood, or outdoors with a gasmask.

Cheap too! Last time I checked, 20 Bucks fer 6 pounds, Clorox Brand.

Thanks for the heads-up! Forewarned is forearmed.