Log in

View Full Version : Azo-Clathrate Primaries: A modification.

April 18th, 2008, 03:38 PM
I hope I am not breaking any rules. I admit that I did not UTFSE. PLease point out any mistakes.

This is a paper I have typed up. The synth is courtsey of SMDB.

Variations and theoretical improvements to Azo-Clathrate Structures.

Patent number is: US3431156.
Experimental :

An alkaline solution of sodium picrate is made as follows:

4.6 grams (four and six tenths gram) pure dry pale yellow picric acid is dissolved with stirring in 180 ml hot distilled water, and to the stirred solution is added a solution of 1.7 grams (one and seven tenths grams) NaOH in 40 ml distilled water. The sodium picrate solution is transferred to an addition funnel and kept warm in a hot water bath.

Into a tall form (Berzelius) 500 ml beaker is placed a magnetic stirbar and 100 ml of distilled water. On a stirrer hotplate is made a hot solution of lead nitrate by adding 25 grams (twenty-five grams) lead nitrate to this stirred 100 ml of hot water. While stirring, this lead nitrate solution is heated to and maintained just below the boiling point. 95 degrees centigrade is fine.

The warm sodium picrate solution is added dropwise slowly at a rate of about one drop every two or three seconds, into the vortex of the vigorously stirred hot lead nitrate solution, continuing stirring and heating for ten minutes after the addition is completed. The precipitated material will initially be bright yellow, and change slowly in color to a darker orange, as a more mature crystalline precipitate is developed towards the end of this step in the synthesis, which results in a suspension of crystalline basic lead picrate, possibly basic lead picrate / lead nitrate double salt, in residual lead nitrate solution.

The valve on the addition funnel is closed, and in the addition funnel is placed a solution of 5.3 grams (five and three tenths grams) of sodium azide dissolved in 50 ml of distilled water. This sodium azide solution is added very slowly by drops, at a rate of about one drop every four or five seconds, to the vigorously stirred suspension of crystals. These basic lead picrate crystals suspended in the stirred mixture with remaining lead nitrate will be changed in color and size as they react with the sodium azide being introduced. This change is due to the formation of the host complex and its subsequent saturation with entrapped lead azide formed within the "cage-crystal matrix" of the host complex. Heating and stirring is continued past the end of this sodium azide addition, for an additonal ten minutes and the heating is then discontinued, yet vigorous stirring of the slowly cooling suspension of microcrystals is continued, maintaining the crystals in suspension for an additional 1 hour as the beaker and its stirred contents slowly air cools. These slow additions and extended periods of stirring are necessary for good completion of the reactions and good crystal formation. The clathrate complex has a very low solubility and so its crystal development is a bit sluggish, and requires the very gradual, steadily maintained and controlled reaction conditions be followed as described for best results.

The stirring is stopped and the reaction mixture is allowed to cool to room temperature. The supernatant liquid is decanted from the crystals, and the crystals are rinsed with 50 ml of distilled water, and washed from the beaker onto a coffee filter with a stream of distilled water from a wash bottle. The filter is placed upon a stack of paper towels to blotter away most of the residual moisture. The granulation mesh of the microcrystals is extremely fine, and there is a point at which the drying crystals are not quite completely dry, when the material may be freed of lumps by light pressure applied by a plastic spoon. The yield of dried crystals is 24 grams, which is 100 per cent of theory.

Try obtaining a 24 gram yield of a first class primary any other way from only 5.3 grams of sodium azide, and the economy of this compound is soon realized.

Ok. That is the synthesis of Azo-Clathrate primary by Mr. Anonymous from science madness. I however have not been able to test this synthesis. Thankfully Microtek and Roscoe Bodine have claimed that they have used this synthesis, unless I am mistaken. I also recall that it worked to make a top notch primary.

I recently came up with an idea. First I shall introduce it to you by telling why it should work. Please note that I have not tried it and if anybody would be so kind could they try it and take many pictures and maybe a video of some tests compared to the usual lead version of the Azo-Clathrate primary explosive.

The usual LEAD version of the AZO CLATHRATE PRIMARY is a very good primary already and is already very customizable. So why meddle with an already very good primary explosive? The answer is simple, to improve it.

As we all know, Silver Azide is a better primary than Lead Azide. I have been led to believe that Silver Picrate also exists from my research. However I have not found it in COPAE, Meyer, or Urbanski.

The theory is simple. Replace the Lead Nitrate in the synthesis with an equimolar mass of Silver Nitrate. Simple. Silver Nitrate has a molar mass of approximately 169.88 grams per mole.

Lead Nitrate has a molar mass of approximately 331.2 grams per mole. Therefore, for 25 grams of Lead Nitrate one must put in 12.823 grams of Silver Nitrate, according to my calculations, however I expect that I have fucked up somewhere in there.

The end result of the synthesis, all going well, would be a Clathrate with better initiating capability due to the Lead Azide being replaced with the better initiating compound, Silver Azide.

I postulate (More of am educated guess really :P) That the resultant clathrate would be of lower density, have higher power, be more brisant than an already Very brisant (insanely so) primary, albeit at a higher cost due to the high cost of Silver Nitrate (32 euro for a 25 gram sample of my lab supplier, Lead Nitrate is 21 euro for a 500 gram sample.) and may not be economical for the lab on a budget, (2 syntheses from Silver Nitrate rather than 20 from Lead Nitrate being made from the sample obtained) and therefore the Lead version may end up being superior (on an economical basis) to the theoretically more powerful Silver variant.

My only fears are that the Silver variant may end up being photo sensitive or very unstable, like Silver Fulminate. Any data on Silver Picrate?

Same deal ran be applied to a Copper variant. Just use Copper Nitrate, with the equimolar mass. But I shall cover that later, however I fear it would be very water soluble. Or just plain unstable.

Finally, will some solubility or crystallization shite stop this from working? Is some simple rule going to shoot me down? Is this a load of bunk? Am I a retard who deserves to be dragged out and shot? All input, be it praise or flaming will be accepted.

April 19th, 2008, 08:45 AM
I am inclined to think that you would get a mixture of silver azide and maybe some oxide depending on what pH you end up with. Maybe also some silver picrate if you're using very concentrated solutions.
Coordination chemistry and crystal growth is not my strongest suit, so I can't tell you absolutely what will happen. However, you should bear in mind that silver is mono valent, which probably makes it hard to build a chlathrate skeleton with it.

Having said that, it is often possible to make coprecipitates that look and act roughly like a homogenous substance, so go ahead and try it out. Then characterize the product and tell us if it is worth anything.

I did a coprecipitation of lead azide and styphnate once by dissolving calculated amounts (for a 80:20 ratio of azide:styphnate) of magnesium styphnate and sodium azide in water, and then adding lead nitrate soln. I don't know if the product was a mixed salt or simply an intimate mix of the two, but it looked homogenous and didn't separate over several years. It worked like you would expect from an intimate mixture (ie. more fuse sensitive than straight azide, very brisant and with very high initiating effect)

Charles Owlen Picket
April 19th, 2008, 09:28 AM
It's early in the morning for me and I honestly don't mean to make one of those "use the Search engine" posts. I'm also not saying this in a mean or hostile fashion....however...

Silver azide is not a "better" primary. It is a different primary in that it utilizes a salt with a differing weight & density. Most of what silver azide can accomplish can be done with dextrinated lead azide. The resistance to static was done thus.....The lessened sensitivity was done thus....And while I appreciate the effort made to examine differing techniques.......(IF you had searched).......this is already well trod ground. For those of you who may be temped to experiment let me first offer a word of caution: Do not fuck with cupric (or copper) azide in any format. Just "don't" - period......The sensitivity of a copper azide is very close to a touch explosive (nearly iodine trinitride sensitive) and it's really not light weight. Fingers will fly. Just take my word on that: I'm not getting paid by the Lead Azide Corporation to keep you from switching to copper; I swear.

First Note:
The azio-clathrate was first brought to light from a patent by Roscoe who is Mr. Anonymous....All of his posts pertaining to the clathrate actually should be read as it would have saved a lot of time. Roscoe & some other fellows REALLY hammered this issue quite in depth & well. TTBoMK he also has at minimum an undergrad chem background & documented his material professionally & clearly. Quite a few folks HAD worked with variants in other metal salts and found that both Roscoe's own variant & Example #4 in the Patent were the viable option for sustained reliability (via substitution experiments) & higher yields. Most of those post are on SM and he did a Hell of a lot of good work.

The clathrate is a lattice crystal. That is one grown within another (or several): think of "lace". One of the most important features of azides is the crystal shape. IF the crystal (lead azide as an example) is produced in needles the result is a highly sensitive material that becomes virtually unusable. The subtle structure of picrate platelets is vital in that it inhibits rigidity to the lattice. Take away that interaction and you have a chance at brittle clathrate structure and the results may be higher sensitivity than desired. The reason for the clathrate's utility in energetics is both economy & longevity. The original work with clathrates was done by a Nun...go figure! Note also....the resultant material is NOT as potent an initiator as lead azide alone. That's a fact. It's more economical....it stretches the base materials but it was NOT adopted by industry.......Because the same dollar stretching mechanism can be accomplished by sophisticated dextrination of the base azide. It's a damn interesting thing, especially if you have a microscope: but it's not the Holy Grail. A great many guys were experimenting with Roscoe's idea when he originally posted it. It's a damn neat thing & he did some damn fine work.

A great deal of experimentation in this area was accomplished and posted already. I not only don't want to reinvent the wheel nor put pointers up to Science Madness but frankly.....we really should have used some searching prior to this entry. I hope by now most people interested in azides have made excursions to the junk yards and gotten their share of material....because azides cost a pretty penny if you need to go to the bio-science supply houses.

I'm repeating a lot of material here (as I didn't expect the clathrate issue to start over once again) but for what it's worth...
Silver salts are generally passed over in energetics due to their expense, sensitivity (excepting the azide) & inconsistency (the use of 99.x% is demanded in energetic applications & impurities like copper & tin have poor results). There was a time when silver azide was used for detonators but with modern research, lead azide was able to accomplish all of what silver azide appeared to do initially. Copper was basically a "no-go" salt. Except for cupric acetylide (at the turn of the 19th century or there abouts) used in some fuse bulbs, it was simply too sensitive and inconsistent for use in industry. Mercury WAS used........Mercury does appear to have a place in energetic salts but today we have the toxicity issue to contend with so that Hg is as expensive as Ag. It's a heavy salt in nitrate format. However if you price out both: they are now about equal depending upon purity level. Their salts cost enormous amounts. A 500gr bottle of silver nitrate and mercury nitrate BOTH cost about $450 today! Note finally that the costs of metals are going through the roof. If you CAN get some 99.x% silver - get it! as with other elements, the costs will not seem to lower themselves with time.

April 19th, 2008, 05:27 PM
Charles: I did do a search, 10 minutes after posting. I found a wealth of data by a fair few people, but none about a silver variant. A nun you say? Nice. But heck, with todays world I believe such a good explosive warrants more discussion, sodium azide being expensive and rare.

I only got 32 hits on google. I was referring to silver azide being better than non dextrinated azide. Also, I believe that it is more brisant. As I am ignoring cost for now to discuss azo clathrates from a scientific perspective. This summer I will attempt to synth it, then I will attempt the silver variant.

I thank you all for the help. Also, Charles, thank you for the warning about copper azide. Should I include it in my .pdf?

Microtek: you just provided a wealth of information. Thank you so much.

Has anybody any actual hard numbers on the azo clathrates? Or have I just used wrong search terms. Also, I joined science madness.

Charles Owlen Picket
April 20th, 2008, 10:45 AM
Well, realistically the clathrate was not used outside of research, because it wasn't really a dollar stretcher. It's an interesting phenomenon, a crystal structure with a crystal (a lattice) but not a truly "better" primary.. A "better" primary would be a more efficient one or less expensive. Azo-clathrate is neither. It DOES work very well. but if compared to lead azide for military or industrial purposes, it doesn't make the grade of "better". It is basically more expensive to manufacture & somewhat less efficient (it's still a great little item however. We are just talking about utility here.)

There are a group of metallic tetrazenes that are somewhat similar in that they are unique in structure and actually function better than tetrazene alone as initiators, but they cost quite a bit to manufacture..... They have a drawback of being exposure sensitive, having lower longevity than many primaries in common usage.

I would ALWAYS put cautions in files detailing energetics. Cupric azide is a known bad-boy. It is the by-product of the use of copper capsules to contain other azides and resulted in lost accessories to the human anatomy.

MANY people have researched metalic azides and some were very close to usurping lead / silver azide as the primary initiators of choice. But some, like mercuric azide, had little idiosyncrasies like crystal restructure which made them hyper sensitive. Silver azide was used in the early 1950's critical component detonators due to it's stability. Silver azide is a damn good initiator! It just costs too much today in light of silver itself rising in cost. Two of the most expensive salts in Technical format (I'm not talking about Gold Chloride or Platinum bla-bla reagent, but tech-grade stuff) are Silver & Mercuric nitrate.

If one has access to nitric acid one of the nicest ways to save real money is to make one's own silver nitrate.

The "Story of the Nun" can be found in some of the citations in "The Patent". She was the originator of the clathrate concept from a western chemist's perspective. I read it years ago. The only way to find info on this and related subjects is to pour over the Patent and find all the citations, extrapolating from articles found in the Library of Congress & some Patents related to the original.

What you will find is a wealth of information. The Examples cited in the Patent were actually not the only ones related to primary explosives. There was some work done with Trinitrophloroglucinol (TPG!), Mehtylpicric acid (m-cresol), & Styphnic Acid also! Phloroglucinol is available via photographic supply outlets for the time being as most people don't know about TPG.

When I go on about collecting books on explosives THIS is what I'm on about. They are rare as hen's teeth and contain some really remarkable stuff. (Off Topic) I found a book called "The Pentaerythritols" by Berlow, Barth, & Snow, American Chemical Society; last published in '58 that detailed some of the most innovative concepts in explosive production in Western society. ...Techniques that are actually production secrets of manufacturers currently. - The material is in the BOOKS! This stuff will be lost in the coming years to all but the largest of corporations.

As the "old timers" like Gerald Hurst pass on, there won't be anyone to take their place. The techniques, especially of efficient, lab-level production will be lost with them! Currently all that is available to the rookie researcher is industry-scale production techniques. {I'm not kidding.} The lab-scale techniques are being lost because all the research is being done in plants; not at small scale labs like in the distant past.

April 21st, 2008, 03:45 AM
Actually, getting silver or silver nitrate is not a problem for me. The price can be negated thanks to chem class. However I do have some silver metal in stock from taking it out of broken watches (Many watches have a silver bracelet that is 99% pure, just melt them down) my stock is about 50 to 60 grams.

I have searched the net extensively since I posted this thread for data on azides, azo clathrates, and picrates. I have found out that Roscoe Bodine Considered a silver variant but did not see the point because of the original azo clathrates customizability. I have yet to obtain the original patent due to lack of time.

A final note for now is that according to my search silver picrate is not all that sensitive when in water so mixing this compound has little to no risk. It seems to be a little used and very stable compound.