Decomposition of Silver Acetylide/D-Salt

[Vinci]

Hello

I red every Silver Acetylide/D-Salt thread I found, but not one of them contained usefull information about the decomposition of Ag2C2*NO3 or pure Ag2C2.

Some references say that it decompose when come in contact with organics. I dont know if it only does in presence of organic when wet or all the time. In fact I never noticed anything like that but I store it in a little plastic box at the moment.

The second question I have is about its color. My standard batches are done with 5g AgNO3 and 110ml water, but I allways get different looking crystals wich can reach every thinkable grey tint. (of course they are all dry, so the color isnt just water)

thanks

[nitro-genes]

About the stability on storage, PATR mentions it to be unaffected by moisture, light and CO, when made properly...
Mixtures of PETN and Double Salts (1:1) that I once made, did seem to be sensitive to light.
I really like Double Salts because it is very safe to make and has a very high acceleration rate of detonation velocity which makes it despite it's low "power" a very good initiating explosive for PETN or RDX.
IIRC a mere 0.07 grams is listed for PETN versus 0.02 grams for lead azide!
It is also stated in PATR that it is less sensitive to friction than lead azide and much less toxic. Reasons enough for me to abandon lead azide...

About your coloring of the product... I had the same problem when I made it for the first time, starting from reagent grade AgNO3.
I think the key is keeping the temperature of the AgNO3/water/HNO3 mixture at 80-90 deg. C. while, very slowly bubbeling the C2H2 through it.
Maybe it has something to do with the impurities in the Calcium Carbide I am using. But the Double Salts made in this way are pearl white, can be kept for years in the light and perform outstanding! :)

Are you starting from silver metal or silver nitrate? And what is the source of your acetylene?

[Child-of-Bodom]

I've dried DS with a little EtOH without any problem, don't know about other solvents though. Just test it by adding a few mg of DS to you favourite solvent, leave it in there for a week, dry it, and if it works it is fine.

For colour change, yes that is normal, the AgNO3 is decomposing to Ag metal anda bit of nitrogen oxides, which oxidises the silver subsequently to blackish stuff. Make it fast, don't let the solution stand for a long time before you bubble C2H2 through it, and store it in a blinded container.

[Nevermore]

i store my DS in freezer in a film container, over a couple years no discolouration has been observed, neither any change in power-sensitivity of the DS. they are inexpensive and easy to make..

[zajcek01]

I'm storing my Ag2C2 under water for over a year and no color change is noticed and exploseve propertys and sensitivity are still the same.

I did some testing and discovered that it is not compatible with acids.

[Diabolique]

I read an article back in the 60's in the Journal of the American Chemical Society of someone making silver acetylide/nitrate in absolute dark. It was photosensitive, and detonated as soon as it was exposed to light. I no longer have the article, unfortunately.

[nbk2000]

Oh, the utility of a light-initiated explosive bears much thinking about. ;) :D

[Cobalt.45]

Would it be possible to use hexanitrobenzene, either alone or as a primary? There's mention of it being sensitive to light.

Patent #4,262,148.

[megalomania]

Can you remember any more specifics about that JACS article, Diabolique? I found a few dozen hits from the 60's but nothing steps out as being the right article.

[Zajcek]

Hmmm, my silver acetylide is dark grey. It was made from highly pure AgNO3 which I borrowed from my school lab.

AgNO3 was dissolved in water and acetylene gas was bubbled trough. Dark grey substance precipitated. The reaction took place at 5*C because it was performed outside in winter.

I'm storing it in water since December 2004 and no color change was observed. I have a small amount of it on a dry place for almost a month and no color change and explosive properties are the same.

I do not know why is it dark, but it is quite powerful....I hared that it should be white or light grayish, but not dark grey like mine is.

Should I try to make it at higher temperature next time, or should I lower the PH with adding some HNO3, or both to get white precipitate?

Maybe my silver acetylide is pure silver acetylide (Ag2C2) and not double salt like Ag2C2*NO3.

I noticed some white crystals ( lumps ) in the suspension of silver acetylide in water. I picked some of them out of the suspension thinking that they were impurities, dried them and lit them. They exploded with similar power as the "grey stuff".

[nbk2000]

Silver salts are light-sensitive, hence their use in photography, so your Ag-acetylide would have darkened after exposure to light.

If you had made it in the dark, and stored it in the dark, it might still have been light colored.

[Zajcek]

It is stored in a glass container under water in dark. It was made outside, when it was dark and a poor light was used....(40W at distance of 15 m)

It' s interesting that the color had not changed since it is dry on my desk. It is still dark gray colored, not darker, not lighter. I even dried it on the sun and I did not notice any color change.

I still think that white and gray stuff are completely different substances.

When I will have more time, I will try to experiment more with different light conditions, temperature and acidity and I will post the results here.

Edit:
I corrected some grammar mistakes.
Thanks c.Tech!

[Diabolique]

Mega: All I can do to help you on finding the JACS article is that it after 1964, and before 1967. It also was a small filler article. My mother tossed all my journals, as well as a collection of comics (you wouldn't believe their value today). It also mentioned how hydrogen and chlorine gasses could be mixed in absolute darkness, and detonate under the influence of light, especially UV. The nearest university that would have JACS that far back is too far away for me to get to.

Cobalt: I do not have any info that I know of on using hexanitrobenzene as a primary explosive or being light sensitive. I'll check Davis and Urbanski later, and keep my eyes open as I catalog my papers.

With that large an excess oxygen balance, HNB would improve the performance of many other explosives. I would expect it would be somewhat shock sensitive with all those nitros. There is a computer program that is excellant for predicting such things (as well as 3-D structurem electromagnet fields, crystal form, etc.), but only the big drug and chemical companies, and national labs, can afford it. I wonder if HNB would improve the initiating and the deflagration-to-detonation properties of lead styphnate.

HNB likely does not see much work done with it due to the resources that are needed to force the additional nitros onto the ring. The Pi-bond resonance of the benzene ring causes nitro-groups to not like to attach to a benzene ring next to another nitro-group.

I have read a paper on using high intensity laser light to initiate explosives, usually PETN. I'll have to relocate it and reread it, it may be of some help.

Mercury fulminate also shows some light sensitivity, particularly UV light. Keeping it in the dark improves its storage life somewhat. AMPC 706 177 indicates that after a year, it can become too degraded to use. Exposure to UV light shortens its storage life tremdously.

I have heard that copper acetylide double-salts are also somewhat light sensitive, and possibly can be made to detonate when exposed to light when prepared in the dark.

[megalomania]

I should have mentioned I don’t actually need you to get the article for me, I just need some keywords to help me find it. Anyone can browse and search the full collection of every American Chemical Society journal at pubs.acs.org

What you cannot do at pubs.acs.org is actually view the journals. Abstracts, yes, first page, sometimes, full view, no. I can view the articles since I have access. All I need to know are a few keywords to help me narrow my search.

Even better you might want to try your hand at pubs.acs.org and see if you can find the article. Just give me the pdf link and I will get it.