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Rosco Bodine
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azidoformamidinium 3,5-dinitro-1,2,4-triazole
This is being posted here as nitrotetrazolate related hypothetical material even though the same post is being duplicated in another older thread as a
followup there.
http://www.sciencemadness.org/talk/viewthread.php?tid=10969#...
Guanyl Azide may possibly form an interesting salt with 3,5-dinitro-1,2,4-triazole. I am uncertain how it may be done, but speculate it may be
possible to first form the aminoguanidine salt of 3,5-dinitro-1,2,4-triazole as an
intermediate.
Attached are some references. Guanazole would be gotten from Dicyandiamide reaction with hydrazine as per US2648671. Hydrazine Sulfate could be
converted to the Hydrazine Dihydrochloride via Calcium Chloride and filtering.
Guanazole (DAT) is diazotized to 3,5-dinitro-1,2,4-triazole as per the method described on page 13 of the Los Alamos technical report attached.
The DNT is neutralized with aminoguanidine bicarbonate or
a double decomposition of perhaps a soluble sodium DNT salt with a soluble aminoguanidine salt perhaps the nitrate,
may work.
Then the aminoguanidine 3,5-dinitro-1,2,4-triazole is converted to the azidoformamidinium 3,5-dinitro-1,2,4-triazole per the method used for
conversion of aminoguanidine perchlorate to azidoformamidinium perchlorate. See Klapotke paper attached, regarding compound 4 page 3.
No search has been done for the speculated compound
azidoformamidinium 3,5-dinitro-1,2,4-triazole ....
existence and properties at this point unknown.
Perhaps this could be a "green primary" class material
or a candidate for investigation.
Attachment: US2648671_PREPARATION_OF_GUANAZOLE.pdf (84kB)
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Attachment: Diazotization of Guanazole to Dinitro Triazole 00312939.pdf (1.5MB)
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Attachment: Aminoguanidine Perchlorate, Triaminoguanidine Perchlorate, Guanyl Azide Perchlorate.pdf (316kB)
This file has been downloaded 1313 times
[Edited on 15-6-2011 by Rosco Bodine]
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AndersHoveland
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Quote: Originally posted by Rosco Bodine  |
The DNT is neutralized with aminoguanidine bicarbonate or
a double decomposition of perhaps a soluble sodium DNT salt with a soluble aminoguanidine salt perhaps the nitrate
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One minor, yet important correction. DNT (or its salts) can actually be reduced by hydrazine to form 3-amino,5-nitro-1,2,4-triazole (ANTA). A
similar reduction would be expected if using aminoguanidine instead of hydrazine.
While the reaction is rapid at 80degC, the reaction is supposedly slower at room temperature, and it is doubtful that a dinitrotriazolate salt of
aminoguanidine, if it exists, would be chemically stable for more than 24 hours.
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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Rosco Bodine
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That very well could be true. If reduction of DNT by aminoguanidine does occur instead of a salt formation, then a workaround would be to first
convert the aminoguanidine to a guanylazide salt and subsequently react with a salt of DNT.
For example perhaps guanylazide nitrate reacted with sodium DNT would accomplish the swapperoo .......er double decomposition. Reaction of
guanylazide perchlorate with ammonium DNT might work also.
[Edited on 24-6-2011 by Rosco Bodine]
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AndersHoveland
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Rosco, you do realize that boiling aqueous guanylazide, in the presence of either a weak base or weak acid, results in cyclization
to 5-aminotetrazole?
Why not just try to prepare 5-aminotetrazole-3,5-dinitrotetrazolate? It would likely not be any less powerful, and it certainly would be much less
sensitive.
There are also dinitrourea salts:
http://docs.google.com/viewer?a=v&q=cache:z1Z4ai1F7qkJ:p...
[Edited on 24-6-2011 by AndersHoveland]
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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Rosco Bodine
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Yes I do understand the reaction sequence continued past the guanylazide intermediate leads to a non-sensitive 5-aminotetrazole product, and so does
the decomposition of tetracene .....however the 5-aminotetrazole DNT is not the compound of interest, as sensitivity is a property which was desired.
Dinitrourea salts would not be expected to be as stable as a DNT salt.
Regarding the 5-aminotetrazoleDNT, granted it does make sense what you say that it would likely not be any less powerful than the guanylazide DNT
derivative, however the guanylazide group is probably going to be a more sensitive energetic group than an aminotetrazole. A "green primary"
is really more what I was contemplating.
It would be expected that for the triazole compound it would be true the same way as for the tetrazole compound, that
an aminotetrazole group would be non-sensitive energetic while an azide group would be favorable to making the azole a more sensitive explosive.
Edit (amended and corrected for clarification)
[Edited on 24-6-2011 by Rosco Bodine]
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AndersHoveland
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You do realize that 5-amino tetrazole can be detonated? Just because it is not sensitive does not mean it is less powerful.
I did not understand you post above, perhaps you should carefully reread my earlier post to be sure you understood it. To repeat, I am saying that
guanylazide NH=C(NH2)--N=N[+]=N[-] , despite being very sensitive, is probably not more powerful than
5-amino-tetrazole NH2--(CN4H).
Notice that both compounds have the same formula: CN5H3
Although azido groups are more powerful than amino groups, one could also similarly/inversely say that tetrazole groups are more powerful than guanyl
groups. Hopefully you understand what I sam trying to say.
Although cyclization of the guanyl azide adds stability (thus reducing heat of formation), the bond strain from the 5-membered ring somewhat
compensates for this. In addition, the presence of the ring would be expected to increase density. It should also be remembered that in high
nitrogen-content explosives without oxygen, heats of formation are less important, as such compounds are more entropic explosives, meaning that the
explosive power comes more from the normal volume of the resultant gas products than the quantity of heat generated to expand the gases.
In any case, sacrificing a little performance would be well worth the decrease in sensitivity. In either case, most of the energy would come from the
dinitrotriazolate anion, so the power contributed by the cation would be less important. Just my opinion.
[Edited on 24-6-2011 by AndersHoveland]
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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Rosco Bodine
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You mean most of the energy would come from the dinitrotriazolate (DNT) rather than dinitrotetrazolate
Edit: I actually did misunderstand above what you were saying and have amended the earlier confused reply above.
The aminotetrazole salt of DNT which you propose is likely
energetic and a valid compound, but is probably non-sensitive as you suggested. It would probably have usefulness in other ways but likely not be
promising as a
"green primary".
It is not any reduction in sensitivity which is being sought.
It was a "green primary" which was the nature of the speculative hypothetical compound.
Attached is an old journal article which describes the preparation of guanylazide nitrate from aminoguanidine, and also describes conversion to
5-aminotetrazole via sodium acetate, as well as how sodium azide may be gotten from guanylazide reaction with sodium hydroxide in excess.
Attached also is a second old journal article describing early identification of structure and general properties.
Attachment: Pages from Journal_of_the_Chemical_Society.pdf (169kB)
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Attachment: Guanylazide Nitrate from Aminoguanidine.pdf (289kB)
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[Edited on 24-6-2011 by Rosco Bodine]
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Rosco Bodine
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azobisformamidine salts
Azobisformamidine dinitrate is gotten from aminoguanidine
nitrate in solution in dilute nitric acid via oxidation by KMnO4
and azobisformamidine is dibasic which could form a series of explosive salts. Azobisformamidine Diperchlorate could be interesting, as could many
other potential salts or double salts. Possibly it could form a diazide or an azide - picrate or a nitrate - perchlorate or a styphnate or a
nitranilate. And of course it may also form a salt of interest with DNT.
Attachment: Azobisformamidine Dinitrate Vol. 1 PATR.pdf (88kB)
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Attachment: Aminoguanidine related _chemistry_.pdf (208kB)
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Attached also is the page 447 referenced with regards to carbamic acid azide to which the azobisformamidine is converted by boiling water.
Attachment: Carbamic Acid Azide page 447.pdf (188kB)
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[Edited on 24-6-2011 by Rosco Bodine]
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Rosco Bodine
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On the first page of this thread I posted a patent
US3663553 Di-Silver Aminotetrazole Perchlorate
and it is attached again here along with a related
paper as a followup describing that and similar
silver compounds.
Attachment: US3663553 Di-Silver Aminotetrazole Perchlorate.pdf (101kB)
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Attachment: 5-Aminotetrazoles and Silver-based Primary Explosives.pdf (853kB)
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Boffis
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Guanidine to aminotetrazole
Hey Rosco the last two attachments in your post of 24-6-11 appear to be from a google book. Please could you give us the title and auther?
I am working on some similar chemistry after I read in an old chemistry text that guanidine racts with 1 molar equivalence of nitrous acid to give
diazoguanidine and then a second mole of nitrous acid to give aminotetrazole. The equation isn't balanced and it hard to see how it could work since
the reaction needs to get a lot of hydrogen from somewhere so I decided to investigate it the reaction. The work is still in progress but this is
where I have got to, my conclusion is that about half of the guanidine is consumed as a reducing agent and nitrogen being liberated.
5-aminotetrazole from guanidine hydrochloride
In H. E. William’s The Chemistry of Cyanogen Compounds (1948 edition) p43 he refers to the reaction of nitrous acid with guanidine. He states that
it progresses in three stages each one reacting one molar equivalent of nitrous acid with the guanidine to give diazoguanidine then amidotetrazole
(=5-aminotetrazole) and finally an explosive diazotetrazole.
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Boffis
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The reaction scheme above is difficult to describe in terms of a balanced equation; in order for the reaction of the diazoguanidine to proceed to
aminotetrazole reduction or transfer of electrons is required. However, during small scale reactions using 2.87 gm of guanidine hydrochloride (0.03M)
per experiment gas was evolved that although brown appears to consist mainly of nitrogen with only a little nitrogen oxides being present. It is
probable therefore, that some of the guanidine is oxidized.
Since this series of reactions appears to offer a route to 5-aminotetrazole form cheap if not exactly OTC chemicals it was decided to carry out some
experiments to determine reaction conditions and establish yields.
Numerous small scale experiments were carried out using guanidine hydrochloride or sulphate with two molar equivalents of sodium nitrite and various
acids (HCl and acetic acid) and on occasions the addition of various reducing agent. The idea behind the addition of the latter was that if nitrogen
is being evolved guanidine is being hydrolysed and oxidized and therefore the addition of a reducing agent may increase the yield from guanidine.
Sodium sulphite and metabisulphite were added either after the addition of one or two molar equivalents of sodium nitrite, the idea behind the
addition after one equivalence of sodium nitrite was to reduce the intermediate diazoguanidine to aminoguanidine (by analogy with the reduction of
diazotized aniline to phenylhydrazine), however, although some strongly exothermic reactions were encountered no aminoguanidine or aminotetrazole
resulted. The preparation given below is the results from the scaling up of the best preparation to date. Scaling up the reaction makes it easier to
handle and reduces mechanical losses.
Theory
Based on William’s scheme one molar equivalent of guanidine hydrochloride should reacts with two molar equivalents of sodium nitrite and one
equivalent of hydrochloric acid to give aminotetrazole. Only one equivalent of hydrochloric acid is required because the guanidine is already combined
with one equivalent of hydrochloric acid which is liberated when the diazoguanidine is formed. Curiously the yield was significantly improved when
only half this amount of hydrochloric acid was added initially.
Preparation details
28.9gm of guanidine hydrochloride (actual weight 0.3M) were dissolved in 30ml of water, solution occurred quickly at room temperature. 42.7gm of
sodium nitrite (0.6M) were dissolved in 60ml of water in a separate vessel, gentle warming was necessary as the nitrite solution becomes very cold.
Both solutions were then chilled in the fridge to about 5°C and then mixed before 16ml of 30% HCl (0.15M) diluted with 16ml of water were added
fairly slowly (over 4-5mins) with gentle swirling to minimise gas loss (Note 1). The solution turned greenish blue and a very small amount of brown
nitrogen oxide was evolved. The solution was placed in the fridge at 3°C for 18 hours over which time it turned yellow and a frothy layer of crystals
separated (Note 2).
The crystals were removed by filtration in a Buchner funnel and dried at 35 to 40°C for 24hrs. The yield was 6.10 gm of slightly cream coloured
crystals. A small quantity was burned in a small crucible and left practically no residue of salt. Interestingly when the dried crystals were removed
from the filter paper a trace of a very fine bright yellow powder remained adhering to the paper, this material deflagrates vigorously without
charring the paper when heated suggesting that it is some form of diazoaminotetrazole derivative and it is probably responsible for both the colour of
the solution and the recovered crystals (Note 3). Work to confirm that the crystals are 5 aminotetrazole has not yet been undertaken.
The yellow filtrate was chilled to near 0°C and a further 16ml of 30% HCl added slowly, the solution turned bluish again but it was harder to
minimise gas loss this time. The solution was placed in the fridge for 24hr; no crystals formed.
The solution was placed in a 250ml squat form pyrex beaker and slowly evaporated to approximately 130ml. Copious quantities of white crystals formed
rapidly as evaporation progressed but it is important not to go below 130ml as this volume of solution is required to keep the sodium chloride in
solution. The solution was cooled to room temperature, filtered at the pump and dried as before yield 13.01gm. The solid was visibly a mixture of
colourless platy crystals, white granular material (salt?) and a small amount of a fine grained bright yellow powder. Further tests show that it
contains a large amount of sodium chloride and work is in hand to determine the best means of extracting the organic material. The yellow powder is
sparingly soluble in water and as with the previous crop is probably a diazoaminotetrazole derivative of some form.
Loss of access to the laboratory until September has prevented further investigation and purification of the product (Note 4). However, given the
significant amount of salt in the second crop the total yield of aminotetrazole, assuming that is what it is, is no more than about 50%. (Theoretical
yield of 5-aminotetrazole would be 31gm)
Note 1 Mechanical stirring caused copious gas loss and significantly reduced yields.
Note 2 Experiments with acetic acid allowed all of the acid to be added at once without excessive loss of nitrogen oxides but the initial yield was
only about 10-12%. This may be because acetic acid is too weak to protonate the tetrazolate ion even when concentrated by evaporation and the sodium
aminotetrazolate is more soluble than the free base.
Note 3 Given the similarity of this reaction with that described Sci. Madness, 5-ATZ(5-Aminotetrazole), the nitrotetrazolate ion and friends, Engager,
8-1-2006; “Synthesis of sodium 5,5 diazoaminotetrazolate from aminoguanidine” the bright yellow substance my well be the diazoaminotetrazole or
its Na salt.
Note 4 Further experiments to isolate the first formed diazoguanidine and to reduce it to aminoguanidine will be attempted later but preliminary
experiments did not appear promising.
 
LEFT After 24hr in the fridge; note the frothy floating platy crystals of aminotetrazole. RIGHT 5 aminotetrazole from the first crop of crystals
(these are from earlier small scale runs)
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Rosco Bodine
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Please post a link to the 1948 edition of Williams. That earlier excerpt was from Victor von Richter Organic Chemistry 1916
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Boffis
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How can I post a link to the 1948 edition of Williams when I can't find one except as a second hand book on Amazon? Thats why I gave the full
reference and and a scan of the relevant section. The 1915 version is available as a download free
at;[url=http://www.archive.org/details/chemistryofcyano00willrich]
I can see little point posting a link to a book on Amazon since when the book is sold it will become and orphan link and Science Madness has enough of
those already. After I bought my volume it wasn't available as an original until recently (there is currently one available), the 2010 reprinted
versions are mostly the earlier 1915 edition and these do not carry the quoted text.
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Boffis
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Thanks for the title! I have manage to download a free copy of Von Richter.
For comparison and in order to have enbough certain 5 aminotetrazole to work with I made some using the dicyandiamde - sodium azide method in US
patent 5451682.
This preparation was take almost verbatim from the US patent 5451682 (link already presented earlier in this post) apart from being scaled up by a
factor of 5. Since I have access to dicyandiamide I used Experiment 2 in the above patent. The only variation was accidental! I had originally planned
to scale up the reaction by a factor of 10 but discovered I didn’t have enough sodium azide and so scaled back the preparation, unfortunately I
forgot that I had already measure out the hydrochloric acid for the final acidification at the x10 ratio. I realized as soon as I had added the HCl
that I had added too much and added an appropriate amount of 10M sodium hydroxide solution to neutralize half the acid but this of course
significantly increased the volume of solution and may have lowered the yield.
Preparation details
In a one litre single neck flat bottom flask equipped with a magnetic stir bar and reflux condenser were placed 50.0 g of dicyandiamide, 38.71 g of
sodium azide and 55.0 g of boric acid in 500 ml of de-ionised water. The solution thus obtained was brought to reflux by which time it had turned
slightly orange. The reaction was allowed to proceed under gentle reflux for 24 hours and then 150 ml of 35% HC1 (1.75M) was added while the solution
was still hot. As mentioned above this is twice the required amount of HCl according to the patent so 87.5ml of 10M (0.875M) sodium hydroxide solution
had to be added to neutralize the excess acid.
The clear reaction mixture was cooled in a fridge for 18 hours where upon a small amount of a white crystalline solid had formed. The mixture was
vigorously stirred to promote crystallisation and left in the fridge for several more hours. The crystalline product was isolated by filtration
however, as filtration proceeded further product crystallized on the stem of the Buchner funnel and in the filtrate. As much of the product as
possible was scraped from the inside of the funnel stem with a spatula and the filtrate stirred vigorously again before being returned to the fridge
for a further 6 hours with frequent vigorous stirring before being filtered through the same funnel as before. The resulting cake was pressed down and
washed twice with 150 ml portions of ice cold distilled water. The solid was then dried in warm oven at about 40°C for 12 hours to the dry
monohydrate. The dried product weighed 65.45gm, 90.3% and had the form of pure white fine bladed crystals.
Note; some loss occurred through crystallisation of the material inside the Buchner funnel and this was not recovered. A further small amount of
crystalline material had formed from the final filtrate when I came to dispose of it! This was not recovered but in any further preparation I will
allow 2 to 3 days in the fridge with frequent vigorous stirring before filtration.
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Rosco Bodine
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FYI, I already had the scanned first edition from 1915 and your excerpt is not in the earlier edition and appears to be obscure, so if there was a
scanned second edition out there it would be better to have the later edition. I was hoping your excerpt was not a scan from your own hard copy. No
such luck huh. I knew about the probable route from guanidine using reaction with hydrazine to form an aminoguanidine intermediate, but Williams
describes dispensing with the hydrazine and getting right to business nitrosating the guanidine which is the first time I have seen this described as
a direct route being possible, even though the name of the compound diazoguanidine would suggest it may be possible
to diazotize guanidine itself instead of diazotizing aminoguanidine. Diazoguanidine and 5-aminotetrazole are isomers and both are monobasic.
It seems possible there could be a monomer - polymer or purely structural difference there more than any significant electron richer / poorer ionic
sort
of difference. It is more a structural kind of thing like a piece of nitinol wire
that transitions from a straight length to a latched ring structure, if I understand correctly. Perhaps another way of looking at it would be the
diazoguanidine is like a bimetal strip with opposite polarity magnetic poles at each end, and when heated it curves around into a loop and snaps
together firmly to form the 5-aminoguanidine ring structure.
[Edited on 14-7-2011 by Rosco Bodine]
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Engager
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This is interesting stuff, however constitution of product is very uncertain. First of all look at reaction from your picture it actually suggests
5-amino-2H-tetrazole witch is different compound with common 5-ATZ witch is 5-amino-1H-tetrazole, i know that 2H isomer exists however i don't know
it's properties. Second concern is that i don't see any reasonable mechanism witch can lead to formation of tetrazole by diazotizing guanidine - just
try to draw it to see that this kind of transformation is kind of magic stuff. To clarify nature of product try to identify it, measure a melting
point - 5-ATZ decomposes without explosion at ~202-204C, try reaction with copper sulfate/sodium acetate solution 5-ATZ should form green precipitate
insoluble in acetic and soluble in hydrochloric acid, closely photograph the crystals - 5-ATZ has a characteristic crystal shape.
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Rosco Bodine
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diazoguanidine freebase reportedly stable ?
Yes it is interesting and I am not following and understanding the reaction as shown by Williams because the reaction is not shown as a balanced
equation.
That leaves much to the imagination about mechanism for the reaction.
For possible insight attached is the entire cyanamide related chapter from the first edition of Williams circa 1915 and the
material of interest here would be pdf page 12, original page 27 half way down the page. But here Williams is speaking
about aminoguanidine as the starting material, not guanidine. Here it seems likely that Williams is misidentifying
a freebase diazoguanidine half hydrate or perhaps a diazoguanidine hydroxide base and this is interesting also because of the description of the
substance being isolated
as a crystalline material having some stability. Other references have stated flatly that diazoguanidine is unstable to the extreme that it can only
be isolated in stable form as its salts. According to Williams description the guanyl azide freebase has reasonable stability and is isolatable
.....so what information on this matter is correct and reliable ?
Looking further at the 1915 Williams article, it appears that what Williams identifies as being Carbamide Imidazide is
actually diazoguanidine or guanyl azide as is more usually
described. A contemporary of Williams, in 1916 von Richter
describes the Carbamide Imidazide as forming a crystalline nitrate m.p.129 which is the melting point of guanyl azide nitrate. This m.p.129 is also
given in other sources including an article attached in my earlier post this page above.
Attachment: Chapter 2 Williams first edition 1915.pdf (1.3MB)
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[Edited on 14-7-2011 by Rosco Bodine]
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Boffis
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You are both right, as I mention in my earlier posts the equation given by Williams is difficult to reconcile and balance that is why I chose to
investigate it. Unfortunately I often work away for long periods and so don’t have access to my laboratory. I am currently away and will not be
home until early September.
If you want I will scan my copy of Williams 1948 and post it to the site library if you don’t think that will violate any copyright.
Going back to the Williams reaction when I tried to balance the equation the problem I encountered was that I needed 2 electron and 2 hydrogen atoms.
There are only two possible reactant either nitrous acid or guanidine. If nitrous acid provided them then it would be oxidized to nitric acid and
hydrogen but this does not sound plausible. That leaves only guanidine not really a well known reducing agent and this is where my equations become
difficult to balance.
A few remarks worth making here;
Diazoguanidine as used by Williams is not an isomer of aminotetrazole nor is it synonymous with guanylazide. Look carefully at his first stage of the
reaction; HONO condenses with an amino group on guanidine in a fashion analogous to say aniline producing a diazo group attached directly to the
central carbon; the product is the CN4H3+ ion. The question is then how does this react with a second molecule of nitrous acid? In my initial scheme a
transient tetra-azo compound is produced that absorbs 2 electron to undergo ring closure to a dehydro iminotetrazole (see attached scan scn_1). This
is then reduced with 2 hydrogens to aminotetrazole. I just can’t see how guanidine can supply the electrons and the hydrogen even though nitrogen is
evolved from the reaction mixture.
There are several possible source of nitrogen, one obvious reaction is a reaction between guanidine and nitrous acid analogous to that between urea
and nitrous acid or perhaps more likely was that urea is being produced as a by product and this then reacted with the excess nitrous acid. I original
though that this indicated that urea was a by-product (hence the attempted equation at the bottom of the page on scn_1). This looked reasonable since
if some of the guanidine was being consumed as a reducing agent with the production urea there would be a large excess of nitrous acid given the
ratios I had used. This is why in some of the earlier experiments I added sodium sulphite as an alternative reducing agent to hopefully improve the
yield. In practice I got no yield at all!
However, just recently I have thought of another possibility, the evolution of nitrogen is reminiscent of diazo coupling or degradation. Suppose the
first formed diazo compound couples immediately with a second molecule of guanidine to produce say a diguanyltriazine or diazoaminodiguanyl this then
reacts with a second molecule of nitrous acid to give a transient diazodiguanyltriazine which then rearranges into aminotetrazole, formic acid and
ammonia with the liberation of nitrogen (see scan scn_2). This mechanism appeals to me because it explains why the reaction works with only half the
theoretical amount of acid and it overcomes most of the problems described above, except one.
The large excess of sodium nitrite I used (given that half the guanidine is converted into by-products) should have converted the aminotetrazole into
a diazo compound and I would have either got 5,5 diazoaminoditetrazole or an explosion. A small amount of a bright yellow explosive compound is
produced but not nearly enough to account for the excess nitrite which is twice that required to diazotize all of the amino tetrazole.
It should be possible to test the various possibilities by reducing the excess of sodium nitrite to get the same or better yield by reducing side
reaction and by looking for formate ions in the residue.
Furthermore it may be possible to isolate the intermediate linear triazine by reducing the sodium nitrite to one quarter of that originally used. I
clearly have a lot of avenues to explore next time I home.
There is of course the possibility that the products do not contain 5-aminotetrazole. The second crop is clearly a complex mixture of salt, a fine
yellow powdery compound and coarser colourless blades. I’ll get back to you in September!
Scans of equation scheme:
Attachment: scn_1.pdf (74kB)
This file has been downloaded 819 times
Attachment: scn_2.pdf (63kB)
This file has been downloaded 784 times
[Edited on 14-7-2011 by Boffis]
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Rosco Bodine
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You may also try working with the nitrate instead of the chloride to see if there is any benefit in the reaction or isolation.
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Engager
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[Edited on 16-7-2011 by Engager]
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Boffis
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I work with the chloride because I have a lots of it and it a pain to convert it to the nitrate. There is also the point that the by-product sodium
chloride has a very flat solubility/temperature curve and so tends not to crystallize out with falling temperature and also tends to salt-out less
dissociated compounds. I have converted some to the nitrate to prepare nitroguanidine but its a tricky process via alkali nitrates so I use silver
nitrate. The silver is easy to recover from the precipitated silver chloride and recycled but its easier for these reaction to work with the chloride
directly.
Whats with the secret picture? If it large just turn it into a pdf and attach.
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Rosco Bodine
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Perhaps the diazotization of guanidine proceeds through formation of a bis compound similar to the azobisformamidine gotten when aminoguanidine is
oxidized by KMnO4. You seem to be looking at something along that line
in your drawn reactions in the second scan. I am not sure but the intermediate
could be something like a bisguanylhydroxylamine if that is possible.
Actually these reactions are a bit mysterious and I find myself reading along to a point where I think I have been following it and then realize the
dots aren't really connecting somehow. It is intriguing huh. This one definitely needs more work.
Identification of the presumed but unconfirmed 5-aminotetrazole may be convenient by the nitrate which should melt at 174-175 with decomposition and
possibly deflagration. For a quantitative ident by titration possibly the picrate ? These are off the top of my head so no references. I know the
guanyl azide isomer forms a picrate.
[Edited on 16-7-2011 by Rosco Bodine]
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AndersHoveland
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This article may shed some light on the mystery:
http://pubs.acs.org/doi/abs/10.1021/j150327a017
"Nitroaminoguanidine, NH2NHC(=NH)NHNO2, on diazotization yields nitroguanidine and nitroguanyl-azide which may be isomerized to 5-nitramine-tetrazole.
Nitroguanyl azide acts as a dibasic acid when titrated with alkalis, as it is quantitatively isomerized to the dibasic nitramine-tetrazole."
http://onlinelibrary.wiley.com/doi/10.1002/jctb.5000681101/a...
Nitroguanyl-azide would have the structure
[-]N=N[+]=NC(=NH)NHNO2
"Nitramine-tetrazole" refers to a compound with the structure
(N4H2C)=NNO2
*note that "nitramines" of tetrazoles exist as a more stable tautomer which actually consists of nitrimino groups instead, with two hydrogens attached
to nitrogen atoms in the ring.
Of course, nitrous acid will not necessarily readily diazotize a guanyl group just because the two regents are reacted;
“Acetamidine nitrite, CH3C(=NH)NH2*HONO prepared by treating concentrated aqueous solution of acetamidine hydrochloride with silver nitrite, melts
at 148C with decomposition, and is soluble in water and alcohol, but insoluble in ether.”
One would be inclined to think that diazotization of a guanyl group would simply change the amino group into a diazonium salt.
R--C(=NH)NH2 --> R--C(=NH)--N[+]ΞN
(C6H5)C(=NH)N=NOH is likely capable of forming a potassium salt, and this could be a possible candidate for the supposed/ mysterious "dioxy-tetrazotic
acid", but if this is the case, it is not entirely clear how this would be reduced by sodium amalgam to the tetrazole.
[Edited on 16-7-2011 by AndersHoveland]
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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Rosco Bodine
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Actually I was looking at both abstracts related to guanidine reaction with nitrous acid early this morning.
The diazotization of nitroaminoguanidine comparison somewhat brings us full circle back to the last few posts near the end of page one of this
interesting thread.
Here attached are the three references of recent mention and interest. Thanks to solo.
Attachment: Diazotization of nitroaminoguanidine.pdf (624kB)
This file has been downloaded 1214 times
Attachment: Guanidine and Nitrous Acid. I.pdf (548kB)
This file has been downloaded 1204 times
Attachment: Guanidine and Nitrous Acid. II.pdf (1.1MB)
This file has been downloaded 988 times
[Edited on 17-7-2011 by Rosco Bodine]
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AndersHoveland
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So it would seem the question is far from settled, as the investigative techniques available at the time of publication were very limited, and the
conclusions are ambiguous. The paper mentions nothing that would correspond to the "dioxy-tetrazotic acid" mentioned in the other paper by Lossen.
[Edited on 17-7-2011 by AndersHoveland]
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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