Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
Author: Subject: Tetraamminecopper(II) persulfate decomposition products
18thTimeLucky
Hazard to Self
**




Posts: 50
Registered: 19-8-2017
Location: The one-and-only tea and crumpet land (UK)
Member Is Offline

Mood: 0 Kelvin and still won't crystallise from solution

[*] posted on 28-12-2017 at 05:57
Tetraamminecopper(II) persulfate decomposition products


I very recently got my hands on some ammonium persulfate and thought I would try myself at synthesising some tetraamminecopper(II) persulfate. For being a weak low explosive I was still rather impressed by the bang produced by detonating miligram quantities wrapped in a couple layers of aluminium foil.
Interestingly, depending on whether confined or unconfined it seemed to change the colour of the decomposition products - sometimes blue, sometimes green and occasionally a little brown or white.

When searching, the decomposition products seem to be barely known and a few years ago it seemed interesting to some SM members to find out these decomposition products. I can't seem to find any results from anybody anywhere though.
I am wondering if anybody knows as I am interested and no online sources seem to have the information readily available, the SM wiki just says:
"...(It) break(s) down into a unknown green solid with no energetic properties..."
"This decomposition may be a reaction with water but is more likely to be a loss of ammonia from the structure."

Just from my short experience and speculation (take this as a pinch of salt as I am not that experienced in chemistry let alone energetics), I can definitely smell ammonia when it decomposes unconfined and maybe something else too but I cannot put my finger on it. The blue colour, found in big patches, maybe is hydrated copper(II) sulfate(VI) as I did not dry my product completely or even wash it with acetone, and therefore the tiny white beads could be anhydrous copper(II) sulfate(VI) where the heat has driven off the water in the tiny beads. The green may be copper(II) nitrates such as basic copper(II) nitrate, a source I did find (http://www.sciencedirect.com/science/article/pii/S1385894714...) mentioned NO3- ions are formed (but no NO or NO2 gas though interestingly and apparently N2 is the main gaseous product). I am not sure what the brown might be though off the top of my head... (other than metallic copper which I doubt)


Also I have had about 8g sitting in the air for almost 24 hours and it still has its brilliant characteristic purple, which confuses me as isn't it supposed to break down in air in a few hours?

Thank you for your time!

IMG_7881[1].JPG - 1.4MB

[Edited on 28-12-2017 by 18thTimeLucky?]




Yep, I have a chemistry blog!
18thtimelucky.wordpress.com

"Amateur chemistry does seem like being in a relationship with someone very beautiful and seductive but has expensive taste, farts a lot and doesn't clean up after themselves, but you love them anyway" - a dear friend
View user's profile View All Posts By User
Laboratory of Liptakov
International Hazard
*****




Posts: 616
Registered: 2-9-2014
Member Is Offline

Mood: No Mood

[*] posted on 28-12-2017 at 08:16


Are you sure, that this is TeACPS ? = Cu(NH 3/4) S2 O8 ? It seems on TeACS. According photo. = thus Cu(NH 3/4) SO4. TeACPS has much longer needles after crystallisation. If reaction temperature is over 10 C, arises xxxx SO4. Under 5 C arises relatively pure xxxx S2 O8. Washing in acetone is condition for next energetic examination.



Safety explosive Alfred Nobel 1867. Safely ecologic detonator Dr. Liptakov 2015.
View user's profile View All Posts By User
18thTimeLucky
Hazard to Self
**




Posts: 50
Registered: 19-8-2017
Location: The one-and-only tea and crumpet land (UK)
Member Is Offline

Mood: 0 Kelvin and still won't crystallise from solution

[*] posted on 28-12-2017 at 08:41


I am quite sure it is tetraamminecopper(II) persulfate (sorry I prefer the full names, abbreviations confuse my tiny brain) as it has very energetic properties (it shredded the aluminium foil when confined) and I do not believe tetraamminecopper(II) sulfate possesses such energetic properties as you are suggesting.
I believe the crystals are not long needles as I crashed it out of solution by adding a concentrated ammonium persulfate solution to a tetraamminecopper(II) sulfate solution (prepared from adding concentrated ammonium hydroxide solution to a saturated copper (II) sulfate solution) in a chilled water bath (just below 10oC I think). I didn't put it in the freezer or anything, as I got a large precipitate that was more than enough product, so there was not time for crystals to grow.

Sorry I do not understand what you mean by "Washing in acetone is condition for next energetic examination."




Yep, I have a chemistry blog!
18thtimelucky.wordpress.com

"Amateur chemistry does seem like being in a relationship with someone very beautiful and seductive but has expensive taste, farts a lot and doesn't clean up after themselves, but you love them anyway" - a dear friend
View user's profile View All Posts By User
Laboratory of Liptakov
International Hazard
*****




Posts: 616
Registered: 2-9-2014
Member Is Offline

Mood: No Mood

[*] posted on 28-12-2017 at 13:03


Sorry I do not understand what you mean by "Washing in acetone is condition for next energetic examination." ------------------------=
Is always better, when are crystalls maximal dry. Acetone removes water from the crystals. For better testing in alu foil or the Anvil.

Sucessful method of preparation:
1) 15g H2O + 5g CuSO4.5H2O = solution A (copper sulfate)
2) 10g NH3 25% aq + 5g (NH4)S2O8 = solution B (ammonium persulfate)
3) Cool solution A on 5 ° C. Solution B cool on 5 ° C.
4) add solution A (slowly drop) into solution B. Hold below 10 ° C. In ice water. Stir one minute.
5) Hold without stirring for 15 minutes on 10C.
6) Arises purple needles. Followed decantation and filtration.
7) Dry at max 40C. The yield should be 4g TeACPS
8) In 20 g of acetone shake 4 g of TeACPS and decanted, dry on filter paper.
9) Dry at max. 40C

Without cooling below 10 ° C, the TeACPS yield decreases dramatically. Instead, it will create a TeACS. ( SO4 in formula)

[Edited on 28-12-2017 by Laboratory of Liptakov]




Safety explosive Alfred Nobel 1867. Safely ecologic detonator Dr. Liptakov 2015.
View user's profile View All Posts By User
18thTimeLucky
Hazard to Self
**




Posts: 50
Registered: 19-8-2017
Location: The one-and-only tea and crumpet land (UK)
Member Is Offline

Mood: 0 Kelvin and still won't crystallise from solution

[*] posted on 28-12-2017 at 13:50


Ok, that's good to know, thanks Laboratory of Liptakov. I don't have a vacuum filtration system so I was hesitant to wash with acetone as I was worried the product would decompose in a few hours and I did not want to wait for the acetone to filter and dry but I guess it is worth it as it seems to take much longer to decompose than I thought and for the extra power (although I am scared enough of the stuff how it is). Also are you saying my product must be quite impure then with some tetraamminecopper(II) sulfate in there as well as I did not cool sufficiently? I do not see why though as the tetraamminecopper(II) sulfate should stay in solution and only the tetraamminecopper(II) persulfate come out due to its poor solubility right?

Still though this is kind of off subject as I am still no closer to finding out the decomposition products.

[Edited on 28-12-2017 by 18thTimeLucky?]




Yep, I have a chemistry blog!
18thtimelucky.wordpress.com

"Amateur chemistry does seem like being in a relationship with someone very beautiful and seductive but has expensive taste, farts a lot and doesn't clean up after themselves, but you love them anyway" - a dear friend
View user's profile View All Posts By User
Laboratory of Liptakov
International Hazard
*****




Posts: 616
Registered: 2-9-2014
Member Is Offline

Mood: No Mood

[*] posted on 28-12-2017 at 23:10


Therefore low stability and weak energetic properties maybe not exist detail study on decomposed products from TeACPS. Is it not attractive compound.



Safety explosive Alfred Nobel 1867. Safely ecologic detonator Dr. Liptakov 2015.
View user's profile View All Posts By User
18thTimeLucky
Hazard to Self
**




Posts: 50
Registered: 19-8-2017
Location: The one-and-only tea and crumpet land (UK)
Member Is Offline

Mood: 0 Kelvin and still won't crystallise from solution

[*] posted on 29-12-2017 at 02:02


That sort of synthesis method information is what should be on the SM wiki. I can't find much to do with anything with this energetic.

I do understand that being a weak primary explosive and slowly decomposing in air makes tetraamminecopper(II) persulfate an unattractive compound, but I would have expected that somebody, who would be interested in discovering something not previously known by the scientific community, would enjoy, in their own time, running tests and figuring out the decomposition products of the relatively very easily synthesised compound.

Heck, if nobody knows the decomposition products I would gladly look into it. It seems you need less an experienced chemist and more somebody who is willing to give up time to forward knowledge on a quite probably useless compound.




Yep, I have a chemistry blog!
18thtimelucky.wordpress.com

"Amateur chemistry does seem like being in a relationship with someone very beautiful and seductive but has expensive taste, farts a lot and doesn't clean up after themselves, but you love them anyway" - a dear friend
View user's profile View All Posts By User

  Go To Top