Sciencemadness Discussion Board

On Acetylides

Polesch - 11-5-2013 at 14:32

I've been doing chemistry for a few years now as a hobbyist, but never felt drawn to chemicals of the explosive kind. I'm pretty much just scared. But one day when reading a 1940's safety manual on welding gas pipes, they mentioned copper acetylide (C2Cu2) as a potential explosive hazard with acetylene and copper pipes.

I've always been taught that explosions are a rapid expansion of gas, and I mostly associate explosives with larger organic molecules with some strained bonds. But on a quick search about copper acetylide, there seemed to be a debate if the detonation had any gaseous products at all, if so, is it just carbon and copper vapor at high speeds?

Well, it was an intriguing compound, and sources said it was more stable than the silver acetylide, so I went to make a some. And to my experience, it was quite stable, it would only detonate after about 5 seconds over a bunsen flame. This was about 35 mg:

But I still haven't found very much information on this, do any of you know more about these types of compounds? Can you think of any more practical uses? Could it work as a primary explosive, as in a blasting cap? I haven't tried to size these up or to confine the compound, maybe some of you more experienced could try to see what this compound is capable of? It's also very easy to make, and much cheaper than the silver acetylide. Do you know of other interesting acetylides with similar properties?

[Edited on 11-5-2013 by Polesch]

Formatik - 11-5-2013 at 15:18

Cuprous acetylide tends to degrade from air and moisture, so it is limited for any application. I also doubt its brisance is even equal to silver acetylide. Chloratotrimercuraldehyde and the perchlorate are two known other acetylene primary explosives, which do have known initiating action.

SA*DS

chemcam - 11-5-2013 at 15:56

I use silver acetylide whenever I can, but have no experience with the cuprous version. SA*DS works well as an initiator and I have not found it to be too sensitive to anything other than a flame. Instant detonation with an open flame even in milligram amounts. I have quite a few videos dealing with SA and SA*DS. My favorite application for small amount of the double salt is for the impact bang-snaps, I just love them. In the thread titled "Relatively safe impact smoke grenade ideas?" I demonstrate it being used for an impact sensitive compound as SA*DS alone, tiny rocks must be added but many mods are also available.

Here is a link to 5mg SA*DS and 25mg ETN in a tiny impact ball. In the other thread I mentioned more videos can be found dealing with SA.

Bert - 11-5-2013 at 20:34

As far as drawbacks: Silver acetylide is EXTREMELY sensitive to static discharges.

So is Silver azide for that matter- I have witnessed both fireing accidentally during handling on dry winter days with no other apparent cause.

Adas - 12-5-2013 at 01:02

Copper acetylide does not create any gaseous products. When initiated in vacuum, it just makes a slight pop. With air it reacts to make CO2 and Cu. Probably if you mixed it intimately with NH4NO3, you would get good results.