Sciencemadness Discussion Board - Silver / Copper Nitride

Silver / Copper Nitride

hodges - 15-4-2004 at 14:47

I have read that silver nitride (Ag3N) is about as easy to make as nitrogen tri-iodide and just as sensitive. Has anyone made it? I'm curious as to why we don't hear more about it. It seems most people would have an easier time getting silver compounds than iodine.

What about copper nitride - is it easily made and is it explosive?

The_Davster - 15-4-2004 at 17:36

I know that the silver was briefly discussed as an off-topic discussion somewhere here. It is made by the heating of silver oxide in concentrated ammonia.

Here is some info on the preparation of nitrides by Blaster:

Quote:

They are easily made from the metal oxide and conc. ammonia soln - heat gently until most of the water has evaporated then allow to air dry.
When making the metal nitrides, you should be safe, even with a bunsen, as long as you don't let it boil dry - the water and ammonia evaporation keeps it below 100'C and therefore below the detonation temperature.
You do need to heat for some time - just boiling briefly isn't enough. My first attempts with the Silver compound failed cos I just boiled it dry with a bunsen within a few seconds. Just as well really!!!
For best results, heat the metal oxide and ammonia on a temperature controlled hot plate at a low heat and add extra ammonia soln two or three times but don't let it dry out between additions!

Ag3N - No Success

hodges - 17-4-2004 at 12:03

I precipitated some Ag2O from a AgNO3 solution using excess NaOH. I put a small amount (miligrams) of this on a flat surface and added 2.5M NH4OH. Although the precipitate did seem to darken from brown to a rather black color, it was not explosive when dry. I scraped and hit it with a broom handle and even tried to ignite it with a barbecue lighter and it did nothing. I got the same results both when leaving the excess NaOH in the precipitate, and when washing it first before adding the NH4OH.

The_Davster - 17-4-2004 at 12:09

Did you do any heating or did you just add the amomoia and filter again? How long did you keep it in the ammonia solution?

BromicAcid - 17-4-2004 at 17:45

I think that I remember reading somewhere that it explodes readily even in solution. I would say that would make it a bit more sensitive then nitrogen triiodide.

hodges - 17-4-2004 at 17:59

Quote:

Originally posted by rogue chemist
Did you do any heating or did you just add the amomoia and filter again? How long did you keep it in the ammonia solution?

I left a small amount of the solution with the precipitate in a test tube. With an eye dropper, I picked up some of the precipitate/solution and placed it on a flat surface. I added NH4OH to this with another eye dropper.

The precipitate that I washed first dried completely. The precipitate with excess NaOH never did dry completely due to the hygroscopic nature of NaOH.

I know 2.5M is not very strong for NH4OH. I have made NI3 quite successfully with this strength before though.

Does anyone have an equation for the reaction that is supposed to occur (fulminating silver)? I searched the net for articles containing Ag2O and AgN3 and didn't find any matches. I have read that the danger during silvering is when the pH of the solution is very high. I think that would imply a reduction, but Ag is +1 in both Ag2O and AgN3 I believe.

[Edited on 4/18/04 by hodges]

The_Davster - 17-4-2004 at 18:50

If I was to be making this(I will when I can get ahold of concentrated ammonia) I would be using a bit larger scale in the procedure. It is possible that the way you did it that there simply was not enough ammonia present.
This what I am planning on doing.
1. .1-.5g Ag2O in a 100mL beaker with ammonia
2. boil till about 20-30 mL of solution is left
3. add more ammonia to the beaker.
4. Repeat steps 2-3 till I'm sick of it

5. filter

[Edited on 18-4-2004 by rogue chemist]

KABOOOM(pyrojustforfun) - 19-4-2004 at 13:22

<blockquote>quote:<hr>Originally posted by hodges Does anyone have an equation for the reaction that is supposed to occur (fulminating silver)? I searched the net for articles containing Ag2O and AgN3 and didn't find any matches...<hr></blockquote>AgN3 is silver azide, silver nitride is Ag3N, equation:
3Ag2O + 2NH3 <s>   ></s> 2Ag3N + 3H2O

BromicAcid - 19-4-2004 at 13:29

Taken from the Comprehensive Inorganic Chemistry series:

Quote:

Silver Nitride

Ag3N

Potassium hydroxide pellets are added to a solution of AgCl in conc. ammonia until the effervescence, caused by the evolving NH3, stops. The mixture is diluted with distilled water, filtered through filter paper, and washed with water until the filtrate is neutral. The moist product is transferred from the filter paper to a porcelain dish, where it may be stored under water for some time.
The product contains small amounts of AgCl and Ag, bus is free of Ag2O.

Alternate Methods: a) A solution of Ag2O in conc. aqueous ammonia is allowed to stand in air or heated on a water bath. The same may be achieved by precipitation with alcohol. The product is impure, with a variable content of Ag2O and Ag [F. Raschig, Liebigs Ann. 233, 93 (1886)].
b) Solid AgF*2NH3 is stored for several days over H2SO4 in a desiccator. The product is free of Ag2O and rich in Ag; the yield is small [L. J. Olmer and Dervin, Bull. Soc. Chim. France (4) 35, 152 (1924)]

SYNONYM:
(Berthollet's) fulminating or detonating silver.

Properties:
Formula weight 337.65. Black flakes, sometimes shining black; crystalline appearance (when prepared according to Raschig, see above). Insoluble in H2O, soluble in dilute mineral acids, explosive reaction with conc. acids. Both the dry and the moist product may be stored in air at room temperature for a long time. Slowly decomposes at 25C. Decomposes at room temperature in vacuum. Decomposes explosively in air at about 165C. Very sensitive (explodes) when touched with objects of great relative hardness, even when moist. Extremely sensitive when dry, but relatively easy to handle when moist. Explodes readily when prepared by Raschig's method. d1/4 9.0. Crystal structure: cubic. Heat of formation (25C): +61.0 kcal./mol.

REFERENCE:
H. Hahn and E. Gilbert. Z. anorg. Chem. 258, 77 (1949).

hodges - 19-4-2004 at 16:48

Thanks, Kaboom and BromicAcid, for the detailed information. Yeah, I meant to type Ag3N not AgN3, it was a typo.

I tried a couple more experiments. I made a more concentrated NH4OH solution using NH4Cl and NaOH. In the first experiment, I had two solutions - one AgNO3 in water and the other NaOH + NH4Cl in water. I made the second solution by adding an excess of NaOH to the water and then adding NH4Cl. Considerable NH3 gas was evolved, and bubbling continued for quite a while. I mixed this with the AgNO3 solution. I got a black precipitate as expected. I left it sit, but it would not dry because of the excess NaOH. So I washed it with a bit of water and let it dry in several small piles (probably around 0.01g each) on a flat surface. Once dry, when touched with the butane flame of a barbecue lighter, there were a few small "rice crispy" pops.

In the second experiment, I mixed NaOH solution with AgNO3 solution and got a black precipitate. I then added NH4Cl. There was only a small amount of bubbling, and it seemed that some of the Ag2O dissolved when I added the NH4Cl. I added more NaOH and got some more bubbling, but I could tell that there was brown Ag2O present in addition to anything else. I let some of this dry and got no reaction whatsoever to a flame.

I'm thinking that Ag3N only forms if it precipitates as it forms. If solid Ag2O is present, maybe it does not react (possibly due to low soluability).

I wonder why the preferred synthesis method calls for AgCl instead of AgNO3. I wonder if there is a reason, or whether AgCl was just thought to be more common.

Success!

hodges - 22-4-2004 at 15:02

I was successful, even without a source of concentrated NH4OH. I took 0.25 grams of AgNO3 and 1g of NH4NO3. I added a small amount of water - just slightly more than required to dissolve the two salts. I used a paper cup. I then slowly, a few grains at a time, added NaOH over a period of an hour or so. Once adding NaOH was no longer giving much NH3 gas, I let it sit for another half hour. I then filled the cup the rest of the way with water. I saw plenty of dark black flakes, some of them appearing to have a bit of silver on them as well. I let this settle for a few minutes, then poured off most of the water. I repeated the washing several times. After the last washing, I left a small amount of water in the cup with the precipitate. Using a plastic dropper, I pulled precipitate/water from the bottom of the cup and deposited it in about a dozen equal amounts on a flat surface.

After drying, each spot gives a loud SNAP! when ignited with a barbecue lighter, blowing out the lighter and leaving only a black mark behind. I also tried setting one off with a piece of string that had been previously soaked in KNO3 solution. With a loud SNAP! (though not much flame that I could see), the wick was thrown several feet into the air. I also tried setting these off by hitting with a broom handle. Most of them could not be set off this way, although two were.

Given the amount of materials I started with and the fact that I lost some during washing, I would estimate each pile had 0.01g of Ag3N in it. The explosions were not as loud as a fircracker, but much louder than toy caps or snappers.

hodges - 1-5-2004 at 13:45

I did some more experiments with this substance. What I have found is that it (at least when made with my above method, which may not be too pure) the substance is similar in sensitivity and power to the substance in toy caps (which is Armstrong's mixture I believe).

I made about 0.15 grams of Ag3N, and kept it under water after washing the precipitate. With a plastic dropper, I pick up small (several miligram) amounts and place the wet drops on a flat surface to dry. Once dry, I can scratch the surface with a wooden stick without it detonating. Hitting it with a piece of metal, however, causes it to detonate just somewhat more loudly than a toy cap gun (do they still make these things?). There is no visible flame - it appears that the substance just dissapears when struck. I even tried measuing the temperature of the surface after detonation with an infrared thermometer. Results varied from no change to a 1 degree C rise in termperature.

If instead of placing the drops of precipitate on a flat surface I place them on a piece of paper towel and then ignite the paper towel when dry, each drop goes off with a bang (again, about as loud as a cap gun) as the flame reaches it.

I took a few pictures and will post later when I've got Windows booted up again (running linux at the moment).

hodges - 2-5-2004 at 15:04

Here is about 150 mg of Ag3N (the black precipitate), sitting under water in a paper cup after preparation and washing:

Here are small spots of Ag3N, placed from the water solution with a plastic dropper. Each spot is several miligrams. The one on the right is nearly dry.

Here is the same shot after detonating the right spot of Ag3N. Very little residue.

Copper nitride synth. failed

kazaa81 - 15-5-2004 at 13:27

I've tried the procedure described in the document extracted from a book, that says to add KOH to an ammoniacal solution of AgCl.
Well, I've added some CuCl in NH4OH and then, added some NaOH.
The dark blue precipitate, when dry, doesn't explode.

Please tell me the correct procedure for making copper nitride.

Thanx at all for the collaboration.

Copper Nitride

hodges - 16-5-2004 at 12:53

I just checked and CRC lists copper nitride as Cu3N, a dark green powder that decomposes in water and in air at 300C. Nothing about it being explosive. Anyway, since it decomposes in water it could not be made in water solution.

sylla - 25-8-2004 at 10:38

I've done silver nitride and the only thing I can say is "TAKE CARE" !

I did 0,05g of it by adding silver nitrate to a drop of NaOH 30% and then adding NH3(aq) 12%. After a few days it became dark and I filtered it. I let it dried and when I touched the crystals with a plastic spoon to collect them : BANG !

So be careful if you try to make it, it's fucking dangerous...

you can also make these (I don't know if they work, I haven't tested it yet but I'm planning to) :

Fulminating Gold : First add as much NH4Cl as you can to HNO3 70% and then add the gold. Wait 10 days and add potassium carbonate, fulminating gold should precipitate

Fulminating Mercury : Add 0,6g of red mercury oxide to 10ml conc NH3(aq) in a sealed tube for 10days, it should turn gray or white.

Fulminating Copper : Add metalic copper to fulminating silver or gold and add a few drops of water.

I've also seen listed as explosives fulminating platinum and other metals but I don't have much more informations...

JohnWW - 25-8-2004 at 13:22

Are you talking about nitrides or azides? The latter would be much more explosive.

BTW "Fulminates" are supposed to be isocyanates, derivatives of the unknown acid HONC, so you cannot have been making these. (Cyanic acid is HOCN)

John W.

sylla - 26-8-2004 at 09:28

just to say that I've tested the fulminating mercury and it works

KABOOOM(pyrojustforfun) - 30-8-2004 at 14:28

Quote:

Originally posted by JohnWW
BTW "Fulminates" are supposed to be isocyanates

fulminates differ from isocyanates see CNO- ion

Saerynide - 4-9-2004 at 09:38

Kinda off topic, but since we're on the topic on nitrides.... How come lithium nitride doesn't explode?

Alternate way to mercury nitride...

Reverend Necroticus Rex - 4-9-2004 at 10:34

Found this, production of what looks like an allotrope of nitrogen prepared electrically in a similar way to ozone that produces mercury nitride directly in one step from the Hg metal itself.

http://lateralscience.co.uk/activen/index.html

The rest of the site is pretty amusing too, especially the fictional Glitch chronicles

neutrino - 4-9-2004 at 16:36

Saerynide:Li3N is more stable than Ag3N because Li is much more reactive than Ag, liberating that pesky octet-preventing electron very easily while Ag prefers to hold onto it. Another reason is no doubt that the covalent radius of silver is so large, while that of nitrogen is so small. This is why NI3 is so unstable.

Quote:

from Encarta
Nitrogen... is converted to an active form by passing through an electric discharge at low pressure. The nitrogen so produced is very active, combining with alkali metals to form azides; with the vapor of zinc, mercury cadmium, and arsenic to form nitrides; and with many hydrocarbons to form hydrocyanic acid and cyanides, also known as nitriles. Activated nitrogen returns to ordinary nitrogen in about one minute.

Oooh...azides from alkali metals in one easy step...

A Slight Mishap

hodges - 17-3-2006 at 15:06

Just got around to posting these. About a month ago I made some silver nitride. When I started to add water to the AgNO3/NH4NO3/KOH following the synthesis, the mixture exploded, splattering all over the ceiling and walls (as well as my shirt and arm).

I suspect that some of the Ag3N had dried on the surface, since I used a minimal amount of water and had let the reaction sit for an hour or so to ensure it was complete. When the first drop of water hit, it exploded. The exploson was not very loud - sounded more like a cork popping out of a bottle than a loud bang. I noted that most of the mixture remained in the plastic cup, which was unharmed.

I quickly washed the mixture off of me since KOH is not particularly good for the skin. After cleaning myself up I wiped the mess off the ceiling and walls. However, it left stains due to the silver. I was later able to remove these completely with dilute HNO3 (which surprisingly did not harm the paint). I washed the Ag3N that remained in the cup and found it to still be explosive upon drying.

Here are some pictures (around 650kB each), taken with a Kodak EasyShare camera:

http://www.sciencemadness.org/scipics/Ag3N_0118.JPG
http://www.sciencemadness.org/scipics/Ag3N_0119.JPG

The black substance in the cup under the water faucet is the Ag3N which exploded. Another cup is visible in one of the pictures; this was from an unrelated experment.

What I was testing is what happens to Ag3N over time. I kept a sample of it under water, and I noted that small bubbles were visible in it for a couple of weeks. After this the bubbles stopped, and I found that the compound is no longer explosive. It also now has a gritty character which the Ag3N did not. I suspect it is now a harmless mixture of Ag and Ag2O.

woelen - 18-3-2006 at 13:11

Hodges, you are talking about Ag3N, but isn't this fulminating silver? (not to be confused with silver fulminate).

If you prepare Tollen's reagent (ammoniacal silver solution), then you always read warnings about the possible formation of so-called fulminating silver. A crystalline crust can form, when an ammoniacal silver solution is allowed to stand for some time. When this crust is cracked, then it explodes. This is why ammoniacal silver solutions should be prepared, just before they are needed, and any solution, left over should be destroyed by acidifying it.

The_Davster - 18-3-2006 at 13:29

Fulminating silver is just another name for silver nitride, Ag3N.

woelen - 19-3-2006 at 11:49

Are you sure about that. I have a book, which states that fulminating silver is a compound of indefinite composition, which can be described as a mix of silver-ammine complexes, with oxygen included as well. The following site gives a net-formula, which also is not correct, formally speaking, but it takes into account the presence of the oxide.

http://www.websters-online-dictionary.org/Fu/Fulminating+sil...

A real accurate formula, giving its structure, cannot be given.

Indeed, fulminating silver may contain some Ag3N, but it definitely is a much more complicated compound.

The_Davster - 19-3-2006 at 12:23

Actually, I was under the impression that it was mostly Ag3N with Ag2NH and AgNH2 in there as well, the presence of oxygen in there is something I have not heard mentioned before.

I looked some relavent things up in Federoff, and you are right, there can be oxygen in there as well. See the attachments.

I have a feeling the precise composition of fulminating silver would depend on very small procedural modifications and that one batch could be radically different from others in terms of composition and sensitivity.

fulminating silver-federoff2.JPG - 93kB

The_Davster - 19-3-2006 at 12:24

Another

EDIT: I have my doubts about your websters link, given its formula for silver fulminate(unless theres been some sort of development here which I was unaware of?) and it implies silver fulminate is the same as fulminating silver despite listing different formulas.

[Edited on 19-3-2006 by rogue chemist]

fulminating silver-federoff.JPG - 41kB

hodges - 19-3-2006 at 19:28

I don't know the exact composition, but would suspect that there is more than just nigrogen involved. It does have a faint odor when detonated - not that of ammonia but I doubt silver alone would have an odor.

Anyway, it is an interesting compound. I've had some stored under water for about a month, and it is no longer reactive. I also let some dry (small amounts) originally and today I find this it still detonates.

Supposedly fulminating copper can be formed by adding a copper salt to fulminating silver. This seems suspicious to me given the low soluability of fulminating silver, which does not appear to dissolve at all when I was it after preparation.

Sometime I want to make fulminating gold. But I have not seen gold in tiny quantities on E-Bay in a while, and I'm not willing to pay the price for gold chloride sold by alternative photography suppliers. I have everything needed to make fulminating mercury, but I'm not going to make something that produces tindy droplets or vapor of mercury as the expected result of detonation.

neutrino - 20-3-2006 at 14:23

Many 1/4, 1/2, and 1 gram pieces of bullion are sold regularly. Just look in the 'coins' section.

woelen - 21-3-2006 at 14:42

Quote:

Originally posted by rogue chemist
Another

EDIT: I have my doubts about your websters link, given its formula for silver fulminate(unless theres been some sort of development here which I was unaware of?) and it implies silver fulminate is the same as fulminating silver despite listing different formulas.

[Edited on 19-3-2006 by rogue chemist]

The link states things a little bit unclear, by putting the section about silver fulminate under the head of fulminating silver. But two definitely different compounds are mentioned. Silver fulminate is a white, well-defined, white salt. It also is described as a white solid on the link, and it has a formula with C, and without H. Fulminating silver, on the other hand, is described as a black solid.

Whatever the precise composition, it is quite complicated and there are many sources, which tell different things. So, it indeed contains Ag3N, but probably also AgNH2, Ag2O, NH3, and who knows what more.

There are quite a lot of this kind of ill-defined compounds. Another well-known example is "ferric ammonium citrate", which contains Fe(3+), NH3, NH4(+), H2O, citrate ion and a lot of combinations of these.

confused?

chatlack - 21-3-2006 at 15:38

A Fulminate must contain CN and the way its produced is about alcohol, nitric acid and grey mercury.. Am I wrong?

Swany - 22-3-2006 at 21:13

"Fulminating", or fulminate is generally an attribute given by early chemists to sensitive explosive materials, and is the root of the happy anion that we know as CNO. Davy refers to NCl3 as a 'fulminating liquid'.

neutrino - 23-3-2006 at 03:16

The fulminate ion is CNO-. Don't confuse this with cyanate, NCO-.

Fulminating does not mean the same thing as fulminate. Silver fulminate is AgCNO, fulminating silver is the mess we're discussing. Just wanted to clear that up.

[Edited on 23-3-2006 by neutrino]

Fulminating Gold

hodges - 18-4-2006 at 13:39

I purchased 1g of gold bullion on E-Bay. I tested the purity by attempting to dissolve in 70% HNO3. As expected, no reaction. I added HCl (5 to 1 by volume). The gold dissolved over the course of a couple hours. Here is a picture of the resulting orange solution, which contains the 1g of dissoved Au. I split this into 5 parts for experiments.
<img src ="http://www.sciencemadness.org/scipics/DSC00671.jpg"></img>

I added concentrated NH4OH and obtained an orange precipitate. I treated part of this precipitate with NaOH (analogy to Ag3N preparation), and left the rest untreated. After allowing to sit for several hours and then washing the precipitate several times, here is how it looked:
<img src ="http://www.sciencemadness.org/scipics/IMG_0322.jpg"></img>

I picked up about 10mg of the precipitate using a pipette. I placed this on the sink to dry.

I also tried using only NH4OH and no NaOH (NaOH might not be required because, unlike with silver solution, the fulminating gold precipitates on adding NH4OH).

Once dry, I found the resulting explosive to be more powerful than, but considerably less sensitive than fulminating silver. When I touched it with the flame of a barbecue lighter, there was a loud pop. However, only the part of the precipitate that was touched by the flame detonated. The rest remained. I was able to get several pops by touching different parts of the precipitate with the flame. Often the flame was blown out. In addition, little pieces of the precipitate scattered nearby so that running the flame of the lighter around on the nearby surface resulted in more pops.

There was not much difference between the precipitate prepared by the two methods, either in look or activity, although I think the batch prepared using only NH4OH seemed to be a bit more uniform and powerful than the batch prepared also using NaOH.

Fulminating silver is much more sensitive. It is impossible to detonate just part of it. However, the pop is nearly as loud with just a portion of the fulminating gold detonating as when the whole 10mg or so of fulminating silver detonates. With fulminating silver, I don't see any smoke. Careful examination shows nearby small particles of something (presumably silver). With the fulminating gold, I got a faint black smoke which appears to have trouble rising very far. Presumably the particles are gold.

I'm sure the fulminating gold would all detonate at once if packed. Fulminating gold seems to be a lot safer than fulminating silver and I think would make a good novelty explosive if it were not for its high cost.

I plan on trying to form gold acetylide at some point. A search for gold acetylide on Google did find matches. It appears to be used for some types of organic chemistry, but no mention is made of whether it is explosive or not.

Phel - 18-4-2006 at 14:41

Hodges, here's a short description of Gold Acetylide taken from PATR2700 vol.1. Hope this helps.

Au2C2.JPG - 71kB

hodges - 19-4-2006 at 17:45

Thanks Phel.

I assume "Very sol in w" means "Very soluable in water". If so, this is going to be hard to separate, unlike silver acetylide.

12AX7 - 19-4-2006 at 19:27

Does that mean, like calcium acetylide, it could be used to prepare acetylides, but not by being the primary source of acetylide(2-) but rather because it's soluble instead of reacting with H2O?

For that matter, why doesn't it just bubble off leaving gold [hydr]oxide and acetylene? I thought acetylide hydrolized because it's an uber weak acid. Does it coordinate?

Tim

CPC - 7-7-2006 at 08:55

Has anyone tried this process for Zinc; using perhaps ZnO?

Zelot - 22-3-2008 at 19:53

@CPC:

Zinc would not work, because zinc nitride decomposes in water.

@everyone:

I recently found out that Longs Drugs sells speaker wire, with one side made of silver wire and the other side made of copper wire. I bought some and was wondering how to make silver oxide from silver. Should I put it in a flame, put some peroxide on it, do electrolysis, or is there some other process?

The_Davster - 23-3-2008 at 00:02

Electrolysis would be best unless you have nitric acid.

Silver anode in a nitrate solution with good stirring should do it, doing it in a base solution may coat the anode too quick, passivating it. A nitrate solution will at least be easier to filter the oxide out of.

However I think it would be preferable to cease the discussion of the precursors for silver nitride in this thread, and put it in a new thread.

Formatik - 19-4-2008 at 13:59

Quote:

Originally posted by hodges
I have read that silver nitride (Ag3N) is about as easy to make as nitrogen tri-iodide and just as sensitive.

But one difference between NI3 ammoniate* and Ag3N, it can explode even under water by contact with hard objects, when dry it explodes from the slightest agitation. In air the compounds sensitivity decreases as it decomposes, and thus after about 10 days its sensitivity is said to have completley worn off. From very concentrated solutions it can explode spontaneously.

*[Note from Gmelin J, pg. 8, NI3.NH3 does explode under water or when wet if it exists in coarse aggregates. I had seen demonstrations of it when wet and figured it didn't react this way, but not necessarily].

You can reduce the explosibility of Ag3N as mentioned in Gmelin [B1] Ag, p. 143 if gelatin is added to the solution to be reacted, this is said to work as a saftey colloid. The risk of explosion is increased if during the preparation the mixture is (1) heated, (2) use of concentrated solutions, (3) unevenness in the walls of the vessels containing it.

Its explosive tendency is minimized when during its preparation NH4+ salts are added which are of oxygen containing inorganic or organic acids in aqueous solution, before the reaction with Ag2O is carried out. For this purpose such NH4+ compounds are NO3-, CO3(-2), SO4(-2), CH3CO2-, citrate and oxalate. To completley protect from the explosion of the system, 0.6 NH4+ equivalent salt per equivalent of Ag2O should be solubilized. This action is thought to be due to a inhibiting action of those compounds having a buffering effect (lowering of the pH).

Quote:

What about copper nitride - is it easily made and is it explosive?

Yes, it is explosive according to Gmelin Cu [B] p. 60, but they say Cu3N is less schock-sensitive than other nitrides citing E.C.Franklin (J.Am.Soc. 34 [1912] 1501/7, 1503). According to one observer there was no decomposition by shock, pressure or friction. It is a green or black powder, or olive-green powder that from the pressure of a polishing stone leaves behind shiny, dark, brass-yellow streaks. Another observer noted green-black for its color. At 300 deg.C. in air it decomposes to Cu and N2 under the formation of light, to other gases (CO2, NH3) first at higher temperatures. Heating in an open tube CuO or a mixture of Cu and Cu2O results. It explodes easily when heated in air.

It's quite difficult to prepare as opposed to Ag3N mixture, e.g. (1) by heating CuO or anhydrous CuSO4 with Mg3N2 which yields a yellow-green copper nitride along with Cu as a thermal decomposition product. (2) heating a mixture of fine copper powder with CaC2 in air forms some copper nitride. (3) reaction of a solution of Cu(NO3)2 in liquid NH3 with KNH2 yields an olive-green compound (likely CuNH2, copper (I) amide, also explosive), which when heated under a vacuum at 160 deg.C. releases NH3 and via Cu2NH converts to Cu3N, in total: 3 Cu(NO3)2 + 6 KNH2 = Cu3N + 6 KNO3 + 4 NH3 + 1/2 N2, etc. Its preparation by heat enough is already impractical without the necessary equipment. Water decomposes it with a strong evolution of heat, so it's not possible to prepare in aqueous solution. But the compound is said to be stable at normal temperatures in air and in a vacuum. It reacts also vigorously with acids, notably energetically with concd. H2SO4 or HNO3.

[Edited on 19-4-2008 by Schockwave]

[Edited on 19-4-2008 by Schockwave]

[Edited on 19-4-2008 by Schockwave]

Formatik - 18-5-2008 at 12:00

"Fulminating copper": just found this. They dissolve pure Cu in dilute HNO3 (might need some heat) and then pour in "liquid Ammonia" (likley just aqueous NH3) to get a precipitate, they dry it (with heat!) and say rubbing it causes a loud explosion. 2 grains (129.6 mg) of it over a fire for a bit is said to produce a loud explosion.

woelen - 18-5-2008 at 13:43

Ins't this simply TACN?

TACN indeed is an explosive compound and it is made from a copper(II) solution with ammonia and nitrate. It is a nice deep blue compound, which pops when heated.

http://woelen.homescience.net/science/chem/compounds/tacn.ht...

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: fixed external link(s)]

[Edited on 7.1.14 by bfesser]

The_Davster - 18-5-2008 at 14:00

I cannot see it as being anything other than the TACN. Keeping in mind the age of that book(1822 (if anyone can get me a pdf of this book, I will be indebted)) and from that age they knew of the fulminating Hg, Ag, Au made by a similar process, but however their characterization at the time may have been insufficient(they did have some awesome characterization methods, but noone may have cared enough to characterize it) so as it came from an identical synthetic route, they called it a fulminating compound.

EDIT: Also note their synthesis of 'fulminating mercury' actually gives mercury fulminate, so their terminology is simply wrong in this book.

EDIT2: Oh my...in many of their syntheses of fulminating/ fulminates they measure a complete washing of a precipitate by the wash water becoming tasteless...including for mercury fulminate

[Edited on 18-5-2008 by The_Davster]

Formatik - 18-5-2008 at 14:09

TACN is probably it. I didn't think about that. Nitric acid at varying strengths reacts differently with metals producing NOx, N2, hydroxylamine, hyponitrous acid, H2, or NH3 , so I was thinking maybe they had formed some other compound.

ShadowWarrior4444 - 18-5-2008 at 14:16

Quote:

Originally posted by The_Davster
I cannot see it as being anything other than the TACN. Keeping in mind the age of that book(1822 (if anyone can get me a pdf of this book, I will be indebted)) and from that age they knew of the fulminating Hg, Ag, Au made by a similar process, but however their characterization at the time may have been insufficient(they did have some awesome characterization methods, but noone may have cared enough to characterize it) so as it came from an identical synthetic route, they called it a fulminating compound.

EDIT: Also note their synthesis of 'fulminating mercury' actually gives mercury fulminate, so their terminology is simply wrong in this book.

EDIT2: Oh my...in many of their syntheses of fulminating/ fulminates they measure a complete washing of a precipitate by the wash water becoming tasteless...including for mercury fulminate

[Edited on 18-5-2008 by The_Davster]

Copper fulminate preparations are found in various places: Powerlabs indicates that a procedure for making Silver, Mercury and Copper fulmate appears here:
http://www.powerlabs.org/chemlabs/fulminate.htm

Also, as for it being TACN, it seems that the preparation involves heating the precursors to 200C. I'm not sure of the decomposition temperature of TACN, however it is likely less than 200C. (The book also mentions using "liquid ammonia," which doesn’t seem to be likely given the 200C evaporation until "wet"--it is likely Ammonium Hydroxide.)

The_Davster - 18-5-2008 at 14:26

While Barros's powerlabs does imply that copper fulminate can be made in the same manner as Ag and Hg versions, this is wrong. Copper fulminate cannot be formed in the same way. In addition he does not provide a source or experiment to back up his claim. Copper fulminate can only be formed from other fulminates; metathesis from sodium fulminate or redox from the silver or Hg salt.

Also, I believe they are using the Fahrenheit scale, so 200F is less than 100C

Formatik - 21-5-2008 at 14:19

Quote:

Originally posted by The_Davster
While Barros's powerlabs does imply that copper fulminate can be made in the same manner as Ag and Hg versions, this is wrong. Copper fulminate cannot be formed in the same way. In addition he does not provide a source or experiment to back up his claim. Copper fulminate can only be formed from other fulminates; metathesis from sodium fulminate or redox from the silver or Hg salt.

Copper fulminate is easily oxidized and doesn't form from a copper and acid attempt. Gmelin (Cu [B] 867) says CuONC is stable in a dry atmosphere but oxidizes easily in moist air, though due to its insolubility it is barely hydrolyzed. The procedure they give for its preparation is done under a H2 atmosphere. It is bright-grey with a green tint and is about as sensitive to heat as Cd and Hg fulminate, but it is less sensitive to impact than those.

It'd be interesting to know which metals besides Ag and Hg do give fulminates. There were some experimentors who tried to get fulminates with other metals in the same manner as Hg and Ag, IIRC metals like manganese, cobalt, copper, zinc, tin, and cadmium but without success.

The website used concentrated acid, it's possible as Liebig did (Ann. Pharm. 95, 284) to obtain Hg(ONC)2 using a subconcentrated acid (56% HNO3): 3 pts Hg dissolved in 36 pts HNO3 (sp. gr. = 1.34 to 1.345) in a wide, large flask so nitrous acid remains in it. Then added this to 17 pts of alcohol which is of 90 to 92 degrees (density) in another vessel, then quickly poured this back into the big flask and swished it around to absorb the nitrous acid. In 5 to 10 minutes gas bubbles form, and then this is further agitated gently and then it turns black with some separation of Hg metal, then a very violent reaction occurs alongside thick white vapors and nitrogen oxides, this can be moderated by adding gradually 17 more pts of the same alcohol. The black goes away and mercury fulminate will start to separate out. The result is also no remaining mercury is said to be in solution.

Howard also used an even lesser concentration, an acid with a d = 1.30 (49%): 1 pt Hg in 7.5 pts HNO3 and mixed with 10 pts alcohol (d = 0.85, 75-77%) and then heated the mixture until it frothed, with the crystals forming on cooling, filtered, washed and dried yielding 1.20 to 1.32 pts Hg(ONC)2.

But one does not need nitric acid for fulminates as it is on that webpage, according to Chemisches Zentralblatt 70 (1884), p. 68, Liebig made AgONC by leading nitrous acid into alcoholic AgNO3. This also does not cause a boiling of the solution. The authors of that article also repeated Liebig’s results with success, but they said there was alongside the fulminate traces of another organic silver salt.

And in place of alcohol with the acid it's possible to use some other organic compounds with at least two carbon atoms, namely lignon, dimethyl- or diethylacetal, acetaldehyde, paraldehyde, metaldehyde, and malonic acid as mentioned in Initialexplosivstoffe by R. Escales, A. Stettbacher, p. 103 and COPAE p. 407.

Quote:

Originally posted by ShadowWarrior4444 Also, as for it being TACN, it seems that the preparation involves heating the precursors to 200C. I'm not sure of the decomposition temperature of TACN, however it is likely less than 200C. (The book also mentions using "liquid ammonia," which doesn’t seem to be likely given the 200C evaporation until "wet"--it is likely Ammonium Hydroxide.)

Close; from Gmelin (Cu [B] 181): TACN melts around 210ºC (decomposing), the melt for a short time develops some gas bubbles and then decomposes explosively at 212ºC.

[Edited on 22-5-2008 by Schockwave]

AJKOER - 18-5-2011 at 14:52

What about Lead Nitride, Pb3N2, not to be confused with Lead Azide, Pb(N3)2?

Properties?

Lead Oxide also reacts with KOH forming a complex (hydroxoplumbates):

PbO + H2O + KOH = K[Pb(OH)3]

With ammonia, 3 possible reactions:

PbO + 3 NH3 + H2O ==> [Pb(NH3)3](OH)2
or:
3 PbO + 2 NH3 ==> N2 + 3 H2O + 3 Pb
or:
3 PbO + 2 NH3 ==> Pb3N2 + 3 H2O

as compared to Silver Oxide, which forms Diamine Silver Hydroxide:

Ag2O +3 NH4OH = 2 [Ag(NH3)2]OH + H2O

which decomposes on standing to Ag3N,

AndersHoveland - 20-5-2011 at 14:49

Some pictures:

Aqueous ammonia (NH4OH) is added to silver nitrate (AgNO3). The result is a light tan precipitate (silver nitride):
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA4/STHTM/AGNO/AGN...

Aqueous ammonia is added to lead(II) nitrate. The result is a white precipitate:
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA4/STHTM/PBNO/PBN...

This does not necessarily mean that the product is lead(II) nitride because a similar reaction is also observed using zinc nitrate, which would not be expected to form a nitride.
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA4/STHTM/ZNNO/ZNN...

Lead(II) salts react with aqueous ammonia to precipitate a white basic salt, Pb2O(NO3)2, rather than the expected lead(II) hydroxide, according to the reaction:

Pb[+2] + (2)NH3(aq) + (3)H2O + 2NO3[-] <==> Pb2O(NO3)2 + H2O + (2)NH4[+]

This basic lead salt is insoluble in excess ammonia.

Mercury Nitride

Mercury(II) nitride forms a chocolate colored powder, which is slowly decomposed by water. The dry nitride tarnishes in air. Mercury(II) nitride is very explosive, and must be handled with extreme care. It detonates violently, yielding a white flame with a bluish purple border, when heated. The salt is so sensitive that it can be detonated by rubbing it with a glass stir rod. It is formed by reacting HgO with NH4OH, initially at 10°C, but thereafter heating the reaction.

Mercury(I) nitrate also reacts with ammonia to form a white precipitate, but I am unsure if this is mercury(I) nitride, or simply a less soluble ammonia complex of mercury(I) nitrate, both of which would be explosive.
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA4/STHTM/HGNO/HGN...

The reaction between mercury(I) nitrate and aqueous ammonia produces a mixture of a white basic amido salt and metallic mercury, both of which precipitate out.

(2)Hg2[+2] + (4)NH3(aq) + NO3[-] + H2O --> (2)Hg + Hg2ONH2NO3 + (3)NH4[+]

Interestingly, another site shows pictures of this reaction giving brownish black colored reaction products, in contrast to the white colored products seen in the other site.
http://www.public.asu.edu/~jpbirk/qual/qualanal/mercury.html
It is possible that different reactant ratios could give different products with correspondingly completely different observable color changes in reaction. Perhaps someone here would like to investigate this?

Another explanation for the precipitate is that the ammonia, because it is a base, causes mercury(I) to precipitate out as a double salt. Even if dissolved in plain water, mercury(I) nitrate is somewhat acidic due to its slow reaction with water:

Hg2(NO3)2 + H2O --> Hg2(NO3)(OH) + HNO3

The Hg2(NO3)(OH) separates out as a yellow precipitate. In the presence of ammonia, it may be possible that some other double salt, with an unknown structure, would form.

Higher nitrides of lead and silver?

I would think one would want to try reacting lead dioxide rather than lead(II) oxide. Despite being very coordinating, the Pb+2 ion does not seem to be much of an oxidizing ion like Ag+1 or Au+3. Lead dioxide dissolves in strong bases. Someone here might try reacting such a solution (of lead dioxide which has been dissolved in aqueous sodium hydroxide) with NH4OH, to see if an explosive lead(IV) nitride can be obtained.

Ag2O4 (silver (I,III) oxide) is also known to dissolve in strong bases. These solutions might also react with NH4OH to produce a different form of silver nitride, with a higher proportion of nitrogen. Ag3N2 ?

Notes about preparation of precursors

(1) lead dioxide may be prepared by oxidizing lead(II) nitrate with potassium ferrate, then adding dilute nitric acid

(2) silver(I,III) oxide can be easily prepared from AgNO3 and sodium persulfate. Here is a video:
http://www.youtube.com/watch?v=1_a81M9p2so

[Edited on 21-5-2011 by AndersHoveland]

AJKOER - 21-5-2011 at 13:31

Some minor corrections on some good research.

2 NH4OH + 2 AgNO3 --> Ag2O(a tan to black solid) + H2O + 2 NH4NO3

Ag2O + 4 NH4OH --> 2 [Ag(NH3)2]OH + 3 H2O

So, with excess ammonia the silver oxide dissolves forming di-amine silver hydroxide.

The latter discomposes on standing forming Ag3N (also some AgNH and AgNH2).

ON THE TOPIC OF LEAD NITRIDE Pb2N3

The compound exists but is (per Bretherick's "Handbook of reactive chemical hazards", page 1884), "Very unstable, it decomposes explosively on vacuum degassing."

AndersHoveland - 21-5-2011 at 14:46

Quote: Originally posted by AJKOER

2 NH4OH + 2 AgNO3 --> Ag2O(a tan to black solid) + H2O + 2 NH4NO3

Ag2O + 4 NH4OH --> 2 [Ag(NH3)2]OH + 3 H2O

So, with excess ammonia...

This may potentially explain the two different results in the two sites that showed pictures of mercury(I) nitrate reacting with ammonia. With excess ammonia, the reaction would turn black, instead of the white precipitate.

When you mentioned lead nitride as "Pb2N3", did you perhaps mean Pb3N2 ?

While the Hg[+2] ion can easily form nitrides, the same is not true of the Pb[+2] ion. So it seems that the more oxidizing the ion is, the easier it is to form nitrides. Of course, if the ion is too oxidizing, it would only simply oxidize the ammonia, liberating nitrogen gas. As mercury(II) nitride readily forms, but not mercury(I) nitride, one would be inclined to think that lead(IV) nitride, if it exists, may be more chemically/thermally stable than lead(II) nitride.

"Lead dioxide... oxidizes ammonia to nitric acid, with the simultaneous formation of ammonium nitrate. It oxidizes manganese salt (free from chlorine) in the presence of nitric acid to permanganate." Encyclopaedia Britannica. Eleventh Edition. Volume XVI. edited by Hugh Chisholm. p318 (year 1911)

I do not know if lead dioxide which has been dissolved alkaline (forming the hydroxyplumbate ion, Pb(OH)6[-2] ) can oxidize ammonia, or ammonium hydroxide reacts with solid PbO2. The article is not clear about whether lead dioxide needs to be acidified to attack ammonia. While lead dioxide is an oxidizer even while alkaline, oxidizing Cr[+3] to CrO4[-2], the salt ammonium chromate does exist, so this does not imply that it would necessarily oxidize ammonia.

[Edited on 21-5-2011 by AndersHoveland]

detonator - 15-7-2011 at 19:23

Then,silver or copper azide salt,more violence.

AJKOER - 29-1-2012 at 16:59

Quote: Originally posted by Formatik

"Fulminating copper": just found this. They dissolve pure Cu in dilute HNO3 (might need some heat) and then pour in "liquid Ammonia" (likley just aqueous NH3) to get a precipitate, they dry it (with heat!) and say rubbing it causes a loud explosion. 2 grains (129.6 mg) of it over a fire for a bit is said to produce a loud explosion.

I suspect this source is referring to Copper Ammonium Nitrate Cu(NH3)4(NO3)2.

First, per Wiki: "Schweizer's reagent is the chemical complex tetraamminediaquacopper dihydroxide, [Cu(NH3)4(H2O)2](OH)2. It is prepared by precipitating copper(II) hydroxide from an aqueous solution of copper sulfate using sodium hydroxide or ammonia, then dissolving the precipitate in a solution of ammonia."

My speculation that in the last step replacing ammonia with NH4NO3 and warming forms Copper Ammonium Nitrate (or CAN), formula Cu(NH3)4(NO3)2. Speculation is based on how other Copper Ammonium salts are prepared.

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0142

Confusion because CAN is capable of (and has been) used as a primer in place of mercury fulminate. See:

http://books.google.com/books?id=dHbHS5GhCN4C&pg=PT70&am...

I am not recommending anyone follows this or Formatik's source synthesis, but if they so elect, please read the MSDS for CAN to avoid potential injury.

[Edited on 30-1-2012 by AJKOER]

Mr. Wizard - 29-1-2012 at 17:20

Back when I took chemistry lab in college, many years ago, I made a solution of (ammoniacal silver) this stuff and put it in a 50 ml ground glass reaction flask for safekeeping, along with my complete set of rented glassware for that semester, and synthesis assignment. I thought it would be safe because I didn't let it get dry. Well , ... I came back on my lab day and opened the locked drawer to find a blackened mess with many dollars worth of expensive glass blasted to bits. I realized immediately what had happened, and closed the drawer, with a few crackling noises. No sense in letting everyone know what a foolish thing I had done. Later I came back and cleaned up and totaled the losses. It could have been worse. A few hundred dollars was a big expense to college student in those days.

This stuff serves no useful purpose, so don't risk your fingers and eyes screwing with it.