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sparkgap
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I was reminded of this thread when I came across the following paper
~~~~~~~~~~~~~~~~~~~
Highly Energetic Tetraazidoborate Anion and Boron Triazide Adducts
Wolfgang Fraenk, Tassilo Habereder, Anton Hammerl, Thomas M. Klapötke,* Burkhard Krumm, Peter Mayer, Heinrich Nöth, and Marcus Warchhold
Department of Chemistry, University of Munich, Butenandtstrasse 5-13 (D), D-81377 Munich, Germany
Abstract:
The first crystal structures of the highly energetic tetraazidoborate anion and boron triazide adducts with quinoline and pyrazine as well as of
tetramethylpiperidinium azide have been determined. Synthesis procedures and thorough characterization by spectroscopic methods of these hazardous
materials are given. Quantum chemical calculations were carried out for B(N<sub>3</sub> <sub>4</sub><sup>-</sup>, B(N<sub>3</sub><sub>3</sub>, C<sub>5</sub>H<sub>5</sub>N·B(N<sub>3</sub><sub>3</sub>, (N<sub>3</sub><sub>3</sub>B·NC<sub>4</sub>H<sub>4</sub>N·B(N<sub>3</sub><sub>3</sub>, and the hypothetical
C<sub>3</sub>H<sub>3</sub>N<sub>3</sub>·[B(N<sub>3</sub><sub>3</sub>]<sub>3</sub> at HF, MP2, and B3-LYP levels of theory. The structure of
tetraazidoborate was optimized to S<sub>4</sub> symmetry and confirmed the results obtained from the X-ray diffraction analysis. The
dissociation enthalpies for the pyridine (model for quinoline) as well as for the pyrazine adduct were calculated. For pyridine−boron triazide a
value of 10.0 kcal mol<sup>-1</sup> (for pyrazine−bis(boron triazide) an average of 2.35 kcal mol<sup>-1</sup> per BN
unit) was obtained.
Source: Inorganic Chemistry, 2001, 40(6), 1334–1340
DOI: 10.1021/ic001119b
http://pubs.acs.org/doi/abs/10.1021/ic001119b
~~~~~~~~~~~~~~~~~~~
Enjoy. 
sparky (~_~)
Attachment: tetrazido.pdf (233kB)
This file has been downloaded 2212 times
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
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Taoiseach
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Here's something interesting I found in an old chemistry book:
1. If a solution of hydrazine sulfate is added to a cold saturated solution of AgNO2, silver azide is formed immediately as tiny crystal needles.
2. 1.5g hydrazine sulfate is heated with 4ml of HNO3 1.3 (what is this density?) and the gas produced is bubbled
through a solution of AgNO3. Silver azide is formed as a thick white precipate.
Method 1 looks the most interesting. AgNO2 is easy to make from AgNO3 and NaNO2. The problem with using a "cold saturated solution" is that this stuff
is hardly soluble in cold water. I dont have solubility data for AgNO2 but I guess it is much more soluble than AgN3. It should then be feasible to
add solid AgNO2 to a warmed solution of HS.
Now we all know that silver azide is a pretty useless compound due to its high sensitivity.
In wet state it is said to be managable tough.
AgN3 is pretty insoluble, at 20°C only 0,0007931g dissolve in 100g water.
However, other silver compounds are even less soluble: AgBr (0,00001328g/100g), AgCL (0,0001923g/100g)
This indicates that a simple metathesis reaction should be possible:
NaCl + AgN3 -> NaN3 + AgCl
The difference between solubilities of AgN3 and AgCl is quite low but it could still work. For example, metathesis between Na2CO3 and CaSO4 works too.
CaSO4 is 0,223g/100g and CaCO3 0,0006170g/100g so the reaction product is 360 times
less soluble.
AgCl is 4 times less soluble than AgN3.
AgBr is 60 times less soluble than AgN3.
*Maybe* this is enough to drive the reaction in reasonable time.
If a suspension of NaCl and AgN3 was made, one could repeatedly remove the water with NaN3 dissolved to increase
speed of reaction.
Anyways some toughts...
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Taoiseach
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*Update*
The AgN3 -> NaN3 route has been worked out before:
http://www.sciencemadness.org/talk/viewthread.php?action=att...
Couldn't be easier Add NaCl solution, wait a few minutes, filter & wash.
Evaporate solution to yield pure NaN3.
Now the question is: How good is the yield of the AgNO2+HS synthesis?
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chloric1
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Quote: Originally posted by Taoiseach  | Here's something interesting I found in an old chemistry book:
1. If a solution of hydrazine sulfate is added to a cold saturated solution of AgNO2, silver azide is formed immediately as tiny crystal needles.
2. 1.5g hydrazine sulfate is heated with 4ml of HNO3 1.3 (what is this density?) and the gas produced is bubbled
through a solution of AgNO3. Silver azide is formed as a thick white precipate.
Method 1 looks the most interesting. AgNO2 is easy to make from AgNO3 and NaNO2. The problem with using a "cold saturated solution" is that this stuff
is hardly soluble in cold water. I dont have solubility data for AgNO2 but I guess it is much more soluble than AgN3. It should then be feasible to
add solid AgNO2 to a warmed solution of HS.
Now we all know that silver azide is a pretty useless compound due to its high sensitivity.
In wet state it is said to be managable tough.
AgN3 is pretty insoluble, at 20°C only 0,0007931g dissolve in 100g water.
However, other silver compounds are even less soluble: AgBr (0,00001328g/100g), AgCL (0,0001923g/100g)
This indicates that a simple metathesis reaction should be possible:
NaCl + AgN3 -> NaN3 + AgCl
The difference between solubilities of AgN3 and AgCl is quite low but it could still work. For example, metathesis between Na2CO3 and CaSO4 works too.
CaSO4 is 0,223g/100g and CaCO3 0,0006170g/100g so the reaction product is 360 times
less soluble.
AgCl is 4 times less soluble than AgN3.
AgBr is 60 times less soluble than AgN3.
*Maybe* this is enough to drive the reaction in reasonable time.
If a suspension of NaCl and AgN3 was made, one could repeatedly remove the water with NaN3 dissolved to increase
speed of reaction.
Anyways some toughts... |
I know it cost a little more but I think sodium bromide would work better. Being that silver bromide is so much more insoluble that silver azide.
Problem is you cannot heat the solution because appreciable amounts of HN3 would be expelled above 37 degrees C. I am not sure slow evaporation would
be much better. It would be better probably take a fairly strong sodium bromide solution and mix with the required amount of silver azide and let
them be together a week or so in a closed bottle with frequent stirring. Take a sample of the filtrate, test for azide, then if the reaction is
complete, then dump the filtrate into a large excess of water soluble solvent that will not dissolve sodium azide. You could use ethanol,
isopropanol, or even better acetone.
Fellow molecular manipulator
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Plasmapyrobattics
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Sodium Azide
Sodium Azide is an important pre-cursor or base material for many Azides. On this thread I could not find any simple and practical synth for Sodium
Azide. The following reaction seems relatively straight forward and easy...
Hydrazine Hydrate + Sodium Nitrite (solution) :
H2N-NH3-OH + NaONO --> NaOH + HN3 + 2H2O --> NaN3 + 3H2O
The NaN3 is crystallized by evaporating the H2O.
Correct? Any other ideas?
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Taoiseach
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Semi-safe (only 2 explosions occured during experimentation ) method for
generating gaseous HN3:
handle.dtic.mil/100.2/AD404719
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Taoiseach
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sorry 4 broken link here's the complete one:
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD404719&Locatio...
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Rosco Bodine
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| Quote: Originally posted by S.C. Wack | | Browne went on to write many other articles in JACS on the subject of hydrazine and hydrazoic acid over the years. |
Attached is some more of the JACS material from early research on azides.
Thanks to franklin for a more legible copy of the original paper attached
Attachment: Chemistry_of_hydronitrides.pdf (1.8MB)
This file has been downloaded 1143 times
[Edited on 7-10-2010 by Rosco Bodine]
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Hydrazine H2SO4
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I have been experimenting lately with hydrazine sulfate (HS), and trying to produce sodium azide. I made HS using Mr. A 's method and found it was
fairly straight forward. What is causing me a lot of grief is going from HS to NaN3. At first I thought maybe my HS was too impure, but after
obtaining a hundred grams of reagent grade HS and having the same problems I now don't think so. I also recrystallized my homemade HS from water after
the first freebasing experiment was very sluggish.
As an example, for my last attempt I used 6g of reagent grade HS. I freebased the HS with about 3.8g of NaOH, added in two separate portions. I did
get a little whiff of hydrazine (ammonia like smell) during the freebasing which was sort of worrisome. I added only a couple drops of water during
the freebasing just to get the reaction between the HS and NaOH going. I did three or four extractions with methyl hydrate (says on bottle 99.9%
pure). I next tried to dissolve another 1.9g of NaOH in the extracts. This is where things get screwed up, I couldn't get all the NaOH to dissolve. I
had to add more methanol until I had a total volume of about 70mL, and when I was using my homemade HS I had an even harder time getting the last NaOH
addition to dissolve.
When I finally did get all the NaOH to dissolve I added the Isopropyl Nitrite. Even after standing for 24 hours (in a little beaker covered with saran
wrap) there was no precipitate. I have done about 5 experiments in the last week or so, 3 of which were with reagent grade HS.
I was hoping Rosco or maybe someone else could help me out. I would really like to make this work.
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quicksilver
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I am hoping that Roscoe would tap into this discussion as it has come up before (to an extent), please see:
http://www.sciencemadness.org/talk/viewthread.php?tid=253
It IS a very interesting subject. I don't know how long you allowed for the synthesis to stand but I think the time of addition (of NaOH) needs to be
lengthy. Please check that thread & compare it to what you were attempting.
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Rosco Bodine
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If hydrazine sulfate was made by Mr. A's improved method, then look no further for "reagent grade" hydrazine sulfate because you made it already.
Microtek described a method that would be worth trying. The details have been described and discussed. I honestly don't have time to do the
reviewing so folks will just have to read through the threads and dig out the particulars. My time is pretty much tied up with some other business
for the next few months so I am just kind of stopping by.
When a known valid method of synthesis can't be reproduced then something is different about the technique, manipulations, or materials being used.
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Hydrazine H2SO4
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It could just be that your technique does not lend itself well to using small quantities. I am using small quantities because I don't want to waste
reagents. I want to be sure I know what I am doing. It is very hard (relatively) to accurately control temperature with small quantities. I don't know
the extent of the oxygen absorbing issue with hydrazine, but given the specific area (area to volume ratio) of a small sample being so much larger,
the oxygen issue must be a lot bigger problem for the small sample. The small sample has for similar reasons a problem with greater evaporation losses
relative to the size of the sample. I am sure I lost a lot of hydrazine hydrate along with the water during some of my freebasing trials. There isn't
much water involved with only a few grams of HS.
I found Microtek's method that you posted. I have given it a try, and for smaller quantities I think it is the way to go. I did get a precipitate but
it is still slow to form. I have been using small beakers and a glass rod, and covering in between manipulations, hovever there is a lot of time when
it is uncovered. Could it be that my hydrazine is just getting oxidized before I get to add the IPN? I am going to get a small erlenmeyer with
stopper, and use magnetic stirring this time.
One thing I have learned is when things are done on a different scale, it can change everything. For instance it is common knowledge that just because
something works on bench scale, does not necessarily mean that it will work full scale in a plant ( in fact it very often does not).
Thanks for pointing out Microteks method.
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Hydrazine H2SO4
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This picture shows a very fluffy precipitate of what I hope is NaN3. I left the beaker sit overnight at room temperature after adding the IPN. In the
first hour there was a small amount of precipitate, (about 1/4 of what is in the picture). I went to sleep soon after, and awoke to what is in the
picture(8 hours later). The beaker is a 100mL beaker, and I started with only 3g of HS.
The reflection makes for a deceiving picture, the beaker only has about a 0.6cm layer of fluff on the bottom, which can be seen from the picture if
you look close. I should have tried for a better picture.
I found Microtek's method with isopropyl alcohol to be much easier to make work, at least in small quantities.
Is it normal for the NaN3 to be this fluffy?
[Edited on 19-4-2011 by Hydrazine H2SO4]
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Microtek
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Have you tested the supposed NaN3? It's wonderfully easy to do qualitative tests for primary explosives after all...
IIRC, the precipitated NaN3 was rather fluffy for me as well.
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Hydrazine H2SO4
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I am already on my way down that road Microtek. I am not near my regular stash of chemicals right now, but I did manage to mooch some silver nitrate
from school. I will get back to you shortly with the results.
Here is what the yeild looks like almost dry on a filter paper(hopefully sodium azide). I filtered and then rinsed with a bit more 99% isopropyl
alcohol.
[Edited on 19-4-2011 by Hydrazine H2SO4]
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Rosco Bodine
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Hydrazine is such a powerfully active reducing agent that really anaerobic or manipulation approaching anaerobic technique with regards to atmospheric
oxygen is a given requirement. No open containers here, except maybe a minimal exposure to air during a rapid pouring of contents from one vessel to
another
would have relatively little loss if there was not a lot of headspace, and you have something of a protective vapor effect provided by fumes of
volatile solvent to
help keep oxygen upstream of the emerging solvent vapors. I hope I am making sense in describing the manipulation technique or concept. It isn't a
strict anaerobic requirement for larger quantities where some oxidation loss is tolerable....
but very truly as you say scale matters, and where you have a small sample
then a small loss may be most of the sample. And yes the thermodynamic of a chemical reaction is related to scale so what is perfectly optimized for
one scale may not work so well on a different scale, and scalability is generally worse for fickle reactions. If you need a kilo see Rosco .....if
you need 10 grams see Microtek
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Hydrazine H2SO4
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Sounds like good advice. I am going to get a small erlynmeyer and use magnetic stirring for the free-basing, rather than using a glass stirring rod
and having the vessel open much of the time as I have been doing.
My dry yeild in the last picture was about 0.75g of Sodium Azide from 3g of HS.
I made some Silver Azide with it using a procedure posted in this thread somewhere I think. This is abbreviated to just give a basic picture of the
process, "3.42 g of AgNO3 is dissolved in 100mL of water, 1.3g of NaN3 is dissolved in 100mL of water in separate beaker, the AgNO3 is heated to
60-70C (I didn't do this), then the NaN3 solution is added slowly with mixing over 3-4 min. The precipatate is filtered and rinsed with water to get
rid of all nitrate, then left to dry". The synthesis says that drying can be done between 70-90C (I just left it overnight on a filter paper at room
temperature).
My yeild was about 1.55g of AgN3. According to the synthesis and adjusted for my 0.75g NaN3 started with I should have gotten a yeild of about 1.73g,
not bad I guess. I tested it, and even a few miligrams makes one hell of a bang. Have a look at the ugly product though. I have never made AgN3
before and didn't realize untill it was to late that there was quite a bit of NaOH with the NaN3. I got a lot of Silver Oxide in my yeild (I think
this is what happened). It is a rookie mistake, oh well I will know for next time. The old Silver Nitrate I used had a fair bit of oxide in it already
as well. I probable should be recrystallizing my NaN3 before using it in a AgN3 synthesis.
The AgN3 sure works well though, and even though it is an ugly product, it shows that I have made NaN3 although I need some refinements.
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Jimbo Jones
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Your nitrate/azide solutions are very diluted. Hot solutions or slow addition also produce bigger (read more sensitive) crystals. Sometimes detonation
accure even in solutions. 10 % sodium azide and 15 % lead or silver nitrate solutions in distilled water are optimum, but I believe there are even
better ratios. Don’t use tap water. This will add a lot of crap like lead chloride, sulphate and carbonate. Stir with plastic straw for around 5
minutes, and then filter 3 times with water. The final wash is with acetonе, to help drying process. Ok, the fun part. You will also need some
sort of colloid or emulsifying agent such dextrine, PVA, CMC, gelatin, guar gum or glycerin. Because I was out of dextrine I chose to use gelatin.
After some beers and thoughts I decide to add 1 % gelatin to the lead nitrate solution. The resulted lead azide has very fine, powder consistency, not
so sensitive to friction or strike (metal & metal) and with nice sensitivty to flame. The bad part. I think I add toooo much gelatin. After some
resurch I found that the ratios are between 0,2 and 0,5 %. The produced lead azide burns like flash powder (no sharp cracks, a.k.a detonation) with
visible black smoke and residue. After the first disapoiment I pressed one cap with lead azide only. Full detonation and shattering on the plastic can
used as witness plate. So after all the azide detonate even in heavy gelatinized form.
The azides are very interesting subject so anyone who can put any furder information is wellcome.
P.S.
Stupid me! No more beers, when reading the old lab notes. The 10 and 15 % solutions actually produce the more sensitive form. Well, maybe the gelatin
helps after all….
[Edited on 21-4-2011 by Jimbo Jones]
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Hydrazine H2SO4
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A friend who has a collection of asssorted new and old glassware at his disposal gave me a 100mL erlynmeyer with ground glass joint and glass stopper.
I ran another freebasing experiment with Hydrazine Sulfate made by Mr. A's method. The freebasing was performed again with Microtek's method. I
started with 6.5g of HS. I added 7.5 mL of isopropyl alcohol, then 2g of NaOH and stoppered the flask. When that had reacted I added an additional
2.2g of NaOH. I let it react for over an hour to be sure it had lots of time to react (it was stoppered the whole time). In the end I had dry white
power (Sodium Sulfate), and a nice clear alcoholic solution of Hydrazine Hydrate. I did 4 extractions, starting with about 30mL of isopropyl alcohol,
and decreasing each time with the last being about 10mL.
I had to add a lot of isopropyl alcohol to dissolve the last 2g of NaOH added to the combined extracts (I actually never got quite all of it to
dissolve, and eventually got impatient and poured the solution into another flask leaving the bit of undissolved NaOH behind)). As can be roughly
quantified from the florence flask picture, I had 225mL or more of liquid before adding the IPN. Sodium Hydroxide seems very insoluble in isopropyl
alcohol.
I added 10.2 mL of IPN, ( I would have added a bit more but that is what I had), to the extracts and covered very tightly with two layers of
polyethylene plastic bound with elastic bands. I let it sit overnight as before. In the morning I awoke to about 1 cm layer of Sodium Azide in the
bottom of the 250mL florence flask.
It should be noted that the freebasing was performed with a lot of head space in the flask, which is not ideal as Rosco pointed out earlier. It was
however well stoppered for almost the whole reaction.
The first picture shows my new 100 mL ground glass stoppered erlynmeyer while in the middle of the freebasing.(I am not sure if that stopper is meant
to go with that flask, but it works and is the right size)
The second picture shows the 250 mL florence flask with about 1 cm of Sodium Azide on the bottom.
 
[Edited on 22-4-2011 by Hydrazine H2SO4]
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quicksilver
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Your dark coloration may have been from some UV (in the sample above). Even a few minutes could do it. Or collectively even from window light over the
course of time.
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Hydrazine H2SO4
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Silver Azide is very light sensitive that is for sure. I left the beaker I used to precipitate the AgN3 out for the last couple of days, with a bit of
AgN3 still in it. The beaker was not even exposed to direct sunlight and the color of the AgN3 has gotten to be about twice as dark.
It was at night when I made the AgN3 with an incandescant bulb hanging from the ceiling for lighting. The AgN3 came out of solution looking exactly
the way it does in the photo, actually darker because it was wet. I think I left a little bit of undissolved NaOH with the hydrazine hydrate extracts
on that first run that most likely ended up with my NaN3 yeild.
It is surprising how photosensitive AgN3 is. I guess it would be a good idea to synthesis it in the dark, or very dim lighting.
It is possible that alkaline pH could result in silver oxide being produced isn't it? I noticed the couple of Silver Azide syntheses I have seen
didn't use NaOH, unlike the couple of Lead Azide syntheses I have seen.
BTW, how much Isopropyl Nitrite should I be adding to the Hydrazine Hydrate Extracts?
It sort of seems by examining the stoichiometry that I used almost twice as much IPN as needed in my last batch. I found the density of my IPN to be
approximatelly 0.86 g/mL, it would changes a bit with temperature though.
I just found a post from 2003 by Mr. Anonomous who says that a slight equimolar excess of IPN should be added to the Hydrazine Hydrate extracts, along
with a slight equimolar excess of NaOH. I think I read that right. The post was actually made by Polverone for Mr. A, and the post had more to do with
making HS than NaN3. It would seem I did add too much.
[Edited on 23-4-2011 by Hydrazine H2SO4]
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Rosco Bodine
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You could possibly chromate the silver azide as a light block and it should make it a pretty scarlet red color. Chromated lead azide is described in
a patent and I could probably dig it up. I have suggested chromating for silver fulminate and
other salts where this may be beneficial as a kind of near insoluble and stable and insensitive barrier coating for reactive or sensitive substrates.
Basically you just stir up into suspension your particles to be chromated and drip in some sodium dichromate or other soluble chromate and let the
metathesis proceed which deposits a nanometers thin plating of the chromate of the cationic portion of the substrate onto the particles. Just an even
coloration is probably a good visual endpoint for this but I have never done it so I can't confirm.
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Jimbo Jones
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Did you use tap or distilled water in the silver nitrate process? Yes, SA is very light sensitive, but I still believe that the silver chloride,
sulphate and carbonate are the main reason for this odd, grey color. I just tested 4 caps with MHN and the heavily gelatinized lead azide. They work
like a charm, but 0,5 % gelatin will be far better!
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Hydrazine H2SO4
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I have never heard of Chromated Azides or Fulminates before, but it sounds really interesting. I also enjoy experimenting with Silver Fulminate, which
definately is another very light sensitive material. I have a feeling that Silver Fulminate is a very good primary which has been unjustly maligned to
a large extent.
I have been using RO water (Reverse Osmosis) water from the Refill Station at the Grocery Store. My tap water here is full of chlorine, and probably
lots of other stuff, which would be no good at all.
I would also like to note that my yeild of Sodium Azide for both runs was about 50% based on Hydrazine Sulfate started with. I believe Rosco said
somewhere that he gets 70 or 80% yeild. I am sure though that I can make many improvements to my process. I am actually just "pleased as punch" that I
can make azides from base chemicals. Having a high yeild is nice, but it is secondary.
[Edited on 23-4-2011 by Hydrazine H2SO4]
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Rosco Bodine
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A virgin synthesis yield of the desired product is usually pleasing, but it gets better after you break her in and get everything properly optimized
Here is a copy and paste from my 03-29-2004 post in ye old E&W forum and tavern where the chromated lead azide was mentioned in the past. The
third patent GB180605 is one of the early Friedrich patents where it is possible that early and unidentified as such azo-clathrates were actually
being produced which were later better described as clathrates
in the Kenney patent.
Copied post below and patents attached
For those who are interested in technical improvements
related to lead azide , here is a little known technology
which may be worthwhile as a source of experimentation .
GB806568
US2989389
The patents describe a process by which lead azide crystals
may be coated with an adherent film of lead chromate ,
by suspension of the crystals in a solution of sodium dichromate .
The result is a free flowing granular form of lead azide having improved
flame sensitivity comparable with Lead Styphnate sensitized mixtures .
While it may not be claimed by the patent , I would guess that the
adherent film of lead chromate probably enhances the resistance of
the lead azide to deterioration from carbon dioxide of the air , which
would improve its long term storage stability .
Early research concerning double salts and multiple salts of lead azide
of interest , is described in another patent of interest :
GB180605
The first double salt mentioned is 95 % lead azide / 5 % basic lead azide .
Many times I have seen it reported that a small percentage of the basic
lead salt greatly improves the crystalline form , handling characteristics ,
and storage stability of "lead azide" . This leads me to speculate that
in those cases where such improvement is reported , what may actually
be described is the formation of such a double salt containing the 5 %
of the basic lead azide . The interest which should lead to experiments
concerning this "95 / 5 double salt" is twofold , in that such an improved
form of lead azide would already have enhanced stability and handling
characteristics over straight lead azide *AND* there is a good chance
that such a double salt could also be "chromated" by a similar method
as the first patent . The potential of such a product is a desirable modification
of lead azide having significant improvement of its handling ,
and storage and ignition properties over pure lead azide .
There have been no experiments by me concerning either one of these
patents . But they are so interesting because of the implications ,
it seemed worth sharing these references and my ideas about their
worthiness for experimentation .
[Edited on 23-4-2011 by Rosco Bodine]
Attachment: GB806568 Chromated Lead Azide.pdf (151kB)
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Attachment: US2989389 US Chromated Lead Azide.pdf (160kB)
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Attachment: GB180605 Lead Azide Double Salts.pdf (286kB)
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