Silver Acetylide Synthese

In the begin-years of this site I vowed myself that I
would never place a synth for a primary explosive on my site.

So why Am
I breaking this promise to myself?
Because in the beginning I only knew
those unstable organic peroxides as primaries.

I'm not saying silver
acetylide is safe, NO primary is, but that's just what we want.
An explosive
sensitive enough to make deflagration to detonation transition in small
quantities.

And this is just a property this explosive masters VERY well

The stuff needed for making SA:

- 2 grams of 99.999% Ag (pure
silver)
- 5 ml of 65% HNO3 (nitric acid)
- a source of
H2C2 (acetylene)
- Distilled water
- Gloves to
handle anything contaminated with AgNO3 solution.
(normal latex
will do)

From left to right: the 2 gram silver plate, the distilled water, and my
source of acetylene; Ca2C2

The first step is
to get that silver in a solution. 65% HNO3 is used for that.

Place the metallic Ag in a test-tube, add the HNO3 and place in a
hot water bath of
about 70°C to accelarate the reaction between the acid and
the silver.

The left pic shows the still cold acid and silver. As you
can see, not much action ...

2HNO3 + Ag =>
AgNO3 + H2O + NO2

In the right pic,
temperature has gone up to a healty 65°C. Work ventilated to avoid the toxic
fumes.

This time, on the left pic, the Ag is allmost completely
dissolved. temperature is a bit over 70°C.
The right pic shows the completed
reaction, with allready a bit of distilled water added.
The AgNO3 was
crystalising out you see, and we want it liquid.

The next step is to
water down the AgNO3 solution some more. If you have
acces to
AgNO3 crystals, you may pick up on the synth from this step too ...

Allways use clean equipement and distilled water, since the slightest
trace amounts
will destabilise and decompose the end product. A good
indicator of this is end product color.

The picture above shows the now diluted AgNO3 solution.

The picture below shows the AgNO3 +
H2C2 reaction:
H2C2(g) +
AgNO3(aq) => Ag2C2(s) + HNO3(aq)

Since this synth is performed in a HNO3 solution, a diffirent product is
obtained, that is
less sensitive to light, and has a higher gas output;
Ag2C2.AgNO3

The reaction goes fairly fast from a milky white in the first second, to
the precipation of
loads of SA within 5 seconds. All depending on the amount
and surface area of H2C2 bubbles,
the concentration of
the AgNO3 solution, temperature and everything else I forgot.

(NOTE: use excess H2C2, since that is alot cheaper
then AgNO3)

Also note that this picture, taken without flash,
shows the real colors. It's a bit creamy.
When SA production comes to a
halt, remove the acetylene source and shut the valve.

It's time to
filter the SA now:

Be prepared for some blitz action, because every second the SA is in
contact with
the organic matter of the filter paper, it's getting
contaminated and decomposed.

Pour the SA + diluted HNO3 solution in the filter, rinse the
reaction vessel a few times with
distilled water to get the last bit of SA
out of the container and wait a bit for most of the water to drip out.

Then move the contents of the filter on to an unreactive plane. A petrie
dish would be perfect,
but I unfortunately don't have one in my posession,
so I used a little mirror.

Now it's time to get the product dry. Mine behaved a bit like pudding
... :)

Place it in a dessicator, but make sure it can't be contaminated by the
dessicant (CaCl2 in this case).

Notice I used a stand for the little mirror to sit on, elevated a few cm
above the dessicant.
I secured both the stand (a cork) as the mirror with
some kind of "tack" adhesive.

As I wait while the SA dries in yet
another DIY dessicator, you have to wait too.
It's good to know that the
tension of what my yield will be is shared :)
----
It's out of the
dessicator, because I didn't quite add enough dessicant, but it's allmost dry
now anyway.
The problem is, there's a faint smell of HNO3, so I'm
leaving it on a warm spot ...

When the smell is gone, I'll weigh it and make an end to this page ...

And then it's testing time :)
----
Okay, due to some circumstances
that I had no control over, here's the far delayed result:
2.25 grams of
Silver acetylide :)

Not optimal, but a very good yield ...

Here's a calculation of what 100% yield should give me:

If
100% Ag2C2:
216(Ag) + 24(C) = 240 => 240/216 = 1.11
grams Ag2C2 for every gram of Ag.

If 100%
Ag2C2.AgNO3:
324(Ag) + 86 (C+N+O) = 410
=> 410/324 = 1.26 grams Ag2C2.AgNO3 for
every gram of Ag.

I think I have >90% yield, which is better then
most synths I do, so I'm pleased.
Also because I only need 0.1 gram per
detonator, so this amount will provide initiation for 22 detonations :)

NEVER use primaries as the main charge, if you want a bigger bang, make
a secondary !!

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