Sciencemadness Discussion Board - mystery stinking compound

mystery stinking compound

hexago - 31-5-2016 at 07:42

Hey,
I recently made a reaction with ammoniac, sulfure and a nail polish remover containing acetone. This gave me three times the same result: after a few days, the liquid starts to become orange and then completely black.
Knowing that sulfur chemistry may be dangerous I tried to open the very smallest vial i had (which was filled with that product) for a few seconds and it stinks like crazy...
I have looked it up online but i can't find any clue on what this is.
thanks for your help
PS: i have posted a picture of the first day and of the last day of the reaction.

mayko - 31-5-2016 at 07:52

Sulfur can dissolve in concentrated sodium hydroxide solutions; perhaps it will slowly dissolve in ammonia? The reaction of basic dissolved sulfur and acetone has also been described. Here's some older threads which might interest you:

http://www.sciencemadness.org/talk/viewthread.php?tid=23236
http://www.sciencemadness.org/talk/viewthread.php?tid=23750
http://www.sciencemadness.org/talk/viewthread.php?tid=23860

hexago - 31-5-2016 at 08:08

thanks for the help
I just begin to understand how vast this forum is

good day

Eddygp - 1-6-2016 at 02:16

The discussion was never really closed in those threads, but I would go for the enolate ion of acetone attacking dissolved sulfur and then the RS- deprotonating water giving OH- (regenerated).

It's a matter of checking whether the OH- is acting as a catalyst. If it isn't, this is most probably not the mechanism.

CuReUS - 1-6-2016 at 02:51

You have replicated in a scientific way,an age-old recipe to make stink bombs

the S reacted with NH₃ to form NH₄SH,which further reacted with more S to form ammonium polysulphide,which is orange yellow

Quote:

Adding sulfur will cause the ammonium sulfide solution to turn yellow-orange as ammonium polysulfide [(NH4)2Sx] is formed. The polysulfide is also used in mineral analyses, though not as often as the regular sulfide.
Sometimes ammonium sulfide solution will turn yellow-orange even when no sulfur has been added. This happens via oxidation by atmospheric oxygen; the result is also polysulfide.

http://www.crscientific.com/nh4sulfide.html

making a stink bomb using NH₃ and matchheads
https://www.youtube.com/watch?v=Zk4UAhsBL1A

nice video on preparation and properties on ammonium sulphide- https://www.youtube.com/watch?v=8IHt_H2j7H0

woelen - 1-6-2016 at 06:13

@CuReUS: I think there is much more to this than sulphur reacting with ammonia. There is acetone in the mix and this gives a deep brown compound under these conditions. Ammonium sulfide is colorless or pale yellow if it contains some polysulfide as well.

I once did a similar experiment, which does not need days to form the brown compound, but only minutes. I added sulphur to acetone. Some sulphur dissolves, most remains undissolved under the acetone. I added highly concentrated solution of NaOH. When this is shaken, then the liquid turns dark brown and a bad smell appears.

With ammonia the reaction is much slower, because of much less strength of the basic solution. It is hydroxide, acetone and sulphur which together give the interesting reaction. I do not know, however, what the brown material is.

Eddygp - 1-6-2016 at 06:37

Quote: Originally posted by woelen

With ammonia the reaction is much slower, because of much less strength of the basic solution.

This is what leads me to think about a possible enolate ion intermediate.
It would lead to sulfanylpropanone (sorry for my possibly mistaken nomenclature). Otherwise a hemithioacetal-like compound, or thioacetal?

zed - 1-6-2016 at 13:11

Well.....you haven't supplied the additional component of heat, but we might be looking at the Willgerodt Reaction. In which case, there would be a Thioamide present in the product.

CuReUS - 3-6-2016 at 00:52

Quote: Originally posted by zed

we might be looking at the Willgerodt Reaction

Zed,you are partly right, see this
http://pubs.acs.org/doi/abs/10.1021/ja01211a083

MeshPL - 5-6-2016 at 10:02

I think that Willgerodt requires a much higher temperature, since even with piridine catalyst temperature required is around 160C. I may be wrong though. For reaction with ammonia a pressure reactor is needed due to so high temperature requirements and volataility of ammonia.

I think that we may also observe formation of some kind of acetone and acetone-ammonia condensation products, which alone are brown, but not so smelly. Triacetone amine is one of the main products of such reactions.