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magyarvegyesz - 11-10-2017 at 01:45

Amstrong's mix is very sensitive, if i where you i don't use it for primer. There are some less sensitive and easy to prepare primers that you can use.

PHILOU Zrealone - 12-10-2017 at 03:09

Quote: Originally posted by Hexogen  
I understand the instability of Armstrong's mixture due to it composing of a strong oxidizer and red phosphorous.

Would it be possible to set off a mix of 9:1 mix of KClO3 and PIB
(Polyisobutylene) ?

Not only that explaination...
Red P is a reducing stuff (thus a fuel for the oxidizer).
Red P is so reducing that it reacts superficially to make some P2O5 (at a lower speed than white P)... the later turns into H3PO4 from air moisture... acids are uncompatible with chlorates since they set HClO3 free and explosive ClO2.
Also P2O5 may set directly very reactive (explosive) Cl2O5 free out of the chlorate...

The PIB/chlorate (KClO3) initiation has already been discussed a few days ago

Hexogen - 14-10-2017 at 03:28

Quote: Originally posted by PHILOU Zrealone  
Quote: Originally posted by Hexogen  
I understand the instability of Armstrong's mixture due to it composing of a strong oxidizer and red phosphorous.

Would it be possible to set off a mix of 9:1 mix of KClO3 and PIB
(Polyisobutylene) ?

Not only that explaination...
Red P is a reducing stuff (thus a fuel for the oxidizer).
Red P is so reducing that it reacts superficially to make some P2O5 (at a lower speed than white P)... the later turns into H3PO4 from air moisture... acids are incompatible with chlorates since they set HClO3 free and explosive ClO2.
Also P2O5 may set directly very reactive (explosive) Cl2O5 free out of the chlorate...

The PIB/chlorate (KClO3) initiation has already been discussed a few days ago


Ah I see, I overlooked the underlying reactions that may occur with the red phosphorus.

Anyway I plan to synthesize a small amount (<15g) of HMTD which I plan to use as the primary ASAP when I prepare the Cheddite C.

kratomiter - 14-10-2017 at 14:30

15 g HMTD, even 10 g, is not a small amount. It is enough to detonate even unconfined.

Hexogen - 14-10-2017 at 18:29

Quote: Originally posted by kratomiter  
15 g HMTD, even 10 g, is not a small amount. It is enough to detonate even unconfined.


That's just a theoretical amount, since I hope to only use it for a blasting cap.

Bert - 14-10-2017 at 21:17

Say hi to Phone for us when you meet him.


Quote:
Originally posted by Bismuth
||
|| Phone's post before he killed himself that weekend are definitely on the E&W archive. See "Storing the AP" on the archive and you'll see his post...
||
|| ===========================================
|| phone
|| February 21st, 2004, 07:08 AM
|| i wonder if in europe there is anyone that uses mehenamine for fire tablets or other things..i found only petrol derivate tablets...
||
||
|| Yeah. They´re german, I don´t have the pack right here, but it´s almost pure methanamine (or how you now spell that lame word). You just solve it in aceton and you get it pure (or was it water) I haven´t really memorized it since I am an AP lamer (but I do own a pack with methanamine), HMTD is nutting for me :P, but hey, first time I did AP I did 80 grams, second 120 grams, third time (yesterday, drying today) something about a kilo or more... :P I GONNA BLOW MY FRICKING ARMS OFF! And yeah, I don´t treat AP with respect, but well, I got plenty of cold, snow and ice outside so my AP is usually quite resistant against pressure e.tc. Well, right now my brain feels like weird, I gonna have to put up a few lamps e.tc. (it dried overnight, switched the newsspaper it was on) and I think I gonna put up a few lamps to get the bitch dry faster. Well, my moms out of the weekend, that´s why I am sitting here with over 1 kilo AP and lots and lots and lots AN. Well, sure, I spam... but.. hey! :P Well.
||
||
|| Well, almost forgot, I always take all my explosives and just make 1 big fucking bomb of it. 1 kilo AP and a couple of kílos AN coming up.
|| ===========================================
||
|| Now, that was Feb 21st. Now we look at this thread posted on Feb 22nd:
|| http://www.sciencemadness.org/talk/viewthread.php?tid=1570



Hexogen - 14-10-2017 at 23:43

Quote: Originally posted by Bert  
Say hi to Phone for us when you meet him.


Quote:
Originally posted by Bismuth
||
|| Phone's post before he killed himself that weekend are definitely on the E&W archive. See "Storing the AP" on the archive and you'll see his post...
||
|| ===========================================
|| phone
|| February 21st, 2004, 07:08 AM
|| i wonder if in europe there is anyone that uses mehenamine for fire tablets or other things..i found only petrol derivate tablets...
||
||
|| Yeah. They´re german, I don´t have the pack right here, but it´s almost pure methanamine (or how you now spell that lame word). You just solve it in aceton and you get it pure (or was it water) I haven´t really memorized it since I am an AP lamer (but I do own a pack with methanamine), HMTD is nutting for me :P, but hey, first time I did AP I did 80 grams, second 120 grams, third time (yesterday, drying today) something about a kilo or more... :P I GONNA BLOW MY FRICKING ARMS OFF! And yeah, I don´t treat AP with respect, but well, I got plenty of cold, snow and ice outside so my AP is usually quite resistant against pressure e.tc. Well, right now my brain feels like weird, I gonna have to put up a few lamps e.tc. (it dried overnight, switched the newsspaper it was on) and I think I gonna put up a few lamps to get the bitch dry faster. Well, my moms out of the weekend, that´s why I am sitting here with over 1 kilo AP and lots and lots and lots AN. Well, sure, I spam... but.. hey! :P Well.
||
||
|| Well, almost forgot, I always take all my explosives and just make 1 big fucking bomb of it. 1 kilo AP and a couple of kílos AN coming up.
|| ===========================================
||
|| Now, that was Feb 21st. Now we look at this thread posted on Feb 22nd:
|| http://www.sciencemadness.org/talk/viewthread.php?tid=1570



Why was he making large amounts of a primary explosive ?

Why was he making TATP ?



Bert - 17-10-2017 at 20:46

Phone.

He was a kid, not an especially thoughtful one, who wanted to hear a big BANG. Then he was a dead kid, scattered over the snow in his local park in Sweden, because he went back to a charge after fire had been applied, as he was both ignorant and impatient (he thought it had failed. It had not...) At least he did not kill his friends or the neighbors in his mother's apartment building.

I responded to that post, probably in the last couple of hours he was alive. Still regret what I wrote, and wish I could have written something to make him see how dangerous what was doing was instead. Some people just can not learn safety any way but by peeing on an electric fence for themselves. Are you one of them?

Hexogen - 18-10-2017 at 01:46

Quote: Originally posted by Bert  
Phone.

He was a kid, not an especially thoughtful one, who wanted to hear a big BANG. Then he was a dead kid, scattered over the snow in his local park in Sweden, because he went back to a charge after fire had been applied, as he was both ignorant and impatient (he thought it had failed. It had not...) At least he did not kill his friends or the neighbors in his mother's apartment building.

I responded to that post, probably in the last couple of hours he was alive. Still regret what I wrote, and wish I could have written something to make him see how dangerous what was doing was instead. Some people just can not learn safety any way but by peeing on an electric fence for themselves. Are you one of them?


I am fully aware of anything that can go wrong (Murphy's law) and is why you cannot skip on PPE and some common sense.
If I wanted to hear a bang, a firecracker would do.
Chemistry is love, chemistry is life.

I have done fireworks before (nothing compared to the power of EM) where people think it's failed only to get almost deafened.

Thank you for bringing this up as it might be sensitive too you, since you may think it's your fault.

PHILOU Zrealone - 18-10-2017 at 03:22

Love of chemistry and love of life is good :)... but careless love of chemistry can be lethal :(

Maybe that he was too enthousiastic about his first succes... and thought he masterizes the stuff and its inherent dangers...
Also the fact he was in a demo mode (kind of braging in front of his friend) didn't help...
==> he was less cautious and careless... then he faced his own death.

Just to ear a good bang... no need for 80g, 120g or 1kg+ CTAP :( nor to risk someone's life...

Edit:
Peroxides are sensitives bitches, HMTD even more so than CTAP...
Playing with it in large amounts is suicidal... even tiny amounts can cause injuries... cristalline stress during cristallization due to an error into the cristal lattice may cause premature detonation under the slightest pressure/friction.
So sometimes it is relatively stable and doesn't cause troubles during handling... but once in a while it does... there are countless reports of those incidents.

[Edited on 18-10-2017 by PHILOU Zrealone]

Bert - 18-10-2017 at 22:17


Quote:

I am fully aware of anything that can go wrong


Nope.

Hexogen - 19-10-2017 at 23:19

Quote: Originally posted by Bert  

Quote:

I am fully aware of anything that can go wrong


Nope.


Everything will go wrong.

nitro-genes - 30-10-2017 at 16:03

The selective reduction of a single nitro group for polynitro arenes is usually performed by the still poorly understood zinin reaction using sulfides. However, according to these papers (1,2): a single nitro group can actually be reduced in high yield using nascent hydrogen under anhydrous conditions.

How can the presence of water make this reaction that much more aspecific? Is it because nitronates form in presence of water and are more easily reduced? How detrimental would only a few percent of water in the reaction be?


(1) Atkins, Ronald L., and William S. Wilson. "Synthesis of polynitrodiazophenols." The Journal of Organic Chemistry 51.13 (1986): 2572-2578.
(2) Anschütz, Richard, and Fritz Heusler. "Ueber die schrittweise Amidirung von mehrfach nitrirten aromatischen Substanzen mittelst Zinnchlorür." European Journal of Inorganic Chemistry 19.2 (1886): 2161-2162.

[Edited on 31-10-2017 by nitro-genes]

PHILOU Zrealone - 31-10-2017 at 03:50

Quote: Originally posted by nitro-genes  
The selective reduction of a single nitro group for polynitro arenes is usually performed by the still poorly understood zinin reaction using sulfides. However, according to these papers (1,2): a single nitro group can actually be reduced in high yield using nascent hydrogen under anhydrous conditions.

How can the presence of water make this reaction that much more aspecific? Is it because nitronates form in presence of water and are more easily reduced? How detrimental would only a few percent of water in the reaction be?


(1) Atkins, Ronald L., and William S. Wilson. "Synthesis of polynitrodiazophenols." The Journal of Organic Chemistry 51.13 (1986): 2572-2578.
(2) Anschütz, Richard, and Fritz Heusler. "Ueber die schrittweise Amidirung von mehrfach nitrirten aromatischen Substanzen mittelst Zinnchlorür." European Journal of Inorganic Chemistry 19.2 (1886): 2161-2162.

[Edited on 31-10-2017 by nitro-genes]

Can you provide me the documents or links to download them?
Thank you in advance for this.

The funny thing is that nascent hydrogen usually refers to naked metal into an acidic media (usually containing water)...
Typical examples of organic chemistry are Zn/HCl, Mg/AcOH,... or Fe/HCl.
I wonder what is their specific anhydrous reduction system?
Zn into glacial AcOH (what is anhydrous)?

Into organic chemistry the solvent/mix of solvents usually pay an important role.
It may favourize certain reaction pathways over others by lowering the general activation energy or lowering one of the intermediary energy "hills"... you may see it as a kind of catalyst or stabilisator of intermediary unstable molecules.
==> There is a change in the speed of reaction/reaction kinetic

So it is a matter of statistic (induced by the different reaction pathway kinetics)...if the water is a strong perturbator of the reaction pathway; then a little will induce a heavy change of composition; if not then % water will have little impact and the process modification will be still good despite a few % water and modification could be smoother.

Water will have a marked influence onto the pH and dissociation constant of the acid/bases/salts... this also has an impact onto many reactions...addition or elimination of H(+) or of OH(-)...etc.

[Edited on 31-10-2017 by PHILOU Zrealone]

nitro-genes - 31-10-2017 at 04:48

Thanks Philou, its an interesting question what determines the selectivity of the reductions, not only regarding the number of nitro groups attacked, but also the position seems dependent on solvent, pH and reducer utilized. :) In the first article a single ortho nitrogroup of TNT is reduced using Fe(0)/AcOH, in the second mentions 2,4 dinitrotoluene reduction to 2-amino 4 nitrotoluene using either tin/HCl/ethanol or ethanol/anhydrous tin(II)chloride. The second article also mentions that Kekule explained in detail in one of his learning books how the presence of water leads to attack of all nitro groups simultaneously (Band II, S. 519), which made me curious what this precise reason is. :)



Attachment: Synthesis of Polynitrodiazophenols.pdf (834kB)
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Attachment: php0wFAMH (104kB)
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[Edited on 31-10-2017 by nitro-genes]

Methylamine perchlorate

kratomiter - 3-11-2017 at 08:46

I want to make methylamine perchlorate from ammonium perchlorate and paraformaldehyde. I have no experience with paraformaldehyde, can I hydrolize it in neutral or acid medium? Typical basic medium with NaOH will form NaClO4 and ammonia gas, so it has to be avoided.
Once the formaldehyde solution is made, the reagents will be reacted in a 1:1 mol basis at high temperature.

ninhydric1 - 3-11-2017 at 10:01

Heat the paraformaldehyde to decomposition. Formaldehyde gas is produced.

kratomiter - 3-11-2017 at 11:20

Quote: Originally posted by ninhydric1  
Heat the paraformaldehyde to decomposition. Formaldehyde gas is produced.


I prefer to work with solutions, formaldehyde gas is not very... friendly. I hope heating in neutral medium with methanol to do the trick. Other trouble is that methylamine perchlorate is very soluble in water so then I have to boil it carefully until precipitation begins.

PHILOU Zrealone - 3-11-2017 at 17:45

Quote: Originally posted by nitro-genes  
Thanks Philou, its an interesting question what determines the selectivity of the reductions, not only regarding the number of nitro groups attacked, but also the position seems dependent on solvent, pH and reducer utilized. :) In the first article a single ortho nitrogroup of TNT is reduced using Fe(0)/AcOH, in the second mentions 2,4 dinitrotoluene reduction to 2-amino 4 nitrotoluene using either tin/HCl/ethanol or ethanol/anhydrous tin(II)chloride. The second article also mentions that Kekule explained in detail in one of his learning books how the presence of water leads to attack of all nitro groups simultaneously (Band II, S. 519), which made me curious what this precise reason is. :)

[Edited on 31-10-2017 by nitro-genes]

Thank you very interesting documents... :)

PHILOU Zrealone - 3-11-2017 at 17:56

Quote: Originally posted by kratomiter  
I want to make methylamine perchlorate from ammonium perchlorate and paraformaldehyde. I have no experience with paraformaldehyde, can I hydrolize it in neutral or acid medium? Typical basic medium with NaOH will form NaClO4 and ammonia gas, so it has to be avoided.
Once the formaldehyde solution is made, the reagents will be reacted in a 1:1 mol basis at high temperature.

Extremely wrong idea...
The process to make methylamine from hexamine (or NH3/CH2=O) is only safe when the hydrochloride is involved (thus hexamine hydrochloride or dihydrochloride)... alternatively NH4Cl/formaldehyde or paraformaldehyde heating.

Formaldehyde is unstable in strongly alkaline media like NaOH... it is subjected to a Cannizaro reaction (disproportionation)... this is actually what happens when methylamine is formed from methylene-imine (discretely hidden into the hexamine)...
CH2=O + CH2=O -base-> CH3OH + HCO2H
CH2=NH + CH2=NH --> CH3-NH2 + HCO2NH4
So formic acid or formiate is formed

The process is strictly forbidden when starting from NH4NO3 and even more so from NH4ClO4...
The all batch may detonate because into the mix in fusion (thus overheated) you have very sensitive hexamine perchlorate/diperchlorate and methylamine perchlorate.
Risk is a little lower from hexamine nitrate/dinitrate and methylamine nitrate... but stil quite possible if you have a hot spot.

==> De nada... I just saved your life, your glasware and saved you a visit from the police

[Edited on 4-11-2017 by PHILOU Zrealone]

kratomiter - 4-11-2017 at 05:33

Thank you for saving my life xD

But are you talking about heating a solid AP/PFA mix? My initial idea was to hydrolize PFA to make a concentrated formaldehyde solution in neutral or slightly acidic media, and then add a AP solution and heat, much like is made with ammonium chloride to make methylamine HCl. Is there any risk of detonation in solution?

Rosco Bodine - 4-11-2017 at 11:33

Quote: Originally posted by kratomiter  
I want to make methylamine perchlorate from ammonium perchlorate and paraformaldehyde. I have no experience with paraformaldehyde, can I hydrolize it in neutral or acid medium? Typical basic medium with NaOH will form NaClO4 and ammonia gas, so it has to be avoided.
Once the formaldehyde solution is made, the reagents will be reacted in a 1:1 mol basis at high temperature.


A special method is required for the nitrate and is probably adaptable for the perchlorate but the details are not found reported. The reaction can be done in aqueous solution with temperature control because the reaction is exothermic and would be scale sensitive and would have safety issues if not controlled.

Paraformaldehyde can be depolymerized by NaOH in H2O with heating to produce a formaldehyde solution.

Relevant patents for methylamine nitrate are EP0037862 and GB1548827 attached

Probably a much safer method would be to first make methylamine hydrochloride and react with sodium perchlorate.





Attachment: EP0037862 methylamine nitrate.pdf (425kB)
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Attachment: GB1548827 methylamine nitrate related.pdf (320kB)
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kratomiter - 5-11-2017 at 07:33

Thank you for the useful patents! I see that isolating pure methylamine perchlorate will be difficult, maybe I should stick to the well known guanidine perchlorate or give a try to gel explosives.

JJay - 5-11-2017 at 17:18

What do people typically use for scrubbing nitrogen oxides when making nitric acid? Will sodium carbonate solution work, or do I need something stronger?


Cryolite. - 5-11-2017 at 17:25

An alkaline water solution would probably work for nitrogen dioxide, but since nitric oxide is so insoluble in water I dont think that sodium carbonate would do a great job with scrubbing it. You could try urea solution-- the nitrogen oxides oxidize it to nitrogen, water, and carbon dioxide.

PHILOU Zrealone - 6-11-2017 at 03:08

Quote: Originally posted by JJay  
What do people typically use for scrubbing nitrogen oxides when making nitric acid? Will sodium carbonate solution work, or do I need something stronger?


H2O2 and Na2CO3 (or NaHCO3) should prove to be usefull...

The H2O2 will oxydise the NO (colorless) to NO2 (yellow) and the HONO to HONO2 (nitous acid to nitric acid).
2 NO2 + H2O --> HONO2 + HONO

So in fine with NaHCO3 or Na2CO3 you end up with recoverable NaNO3 and H2O and gaseous CO2...

Lately I have used HNO3(69%) and metallic Ag... you get some NxOy...
The use of H2O2 discolored immediately all NxOy color from the liquid reactant, it bubbled some O2 and accelerated a bit the very slow dissolution of the 99,99% Ag wire.

PHILOU Zrealone - 6-11-2017 at 03:19

Quote: Originally posted by kratomiter  
Thank you for the useful patents! I see that isolating pure methylamine perchlorate will be difficult, maybe I should stick to the well known guanidine perchlorate or give a try to gel explosives.

The patents mentions only the nitrate variant not the perchlorate one...
But:
1) It is low yielding at the 100°C used and it is dangerous... because exothermic (into the mix you have a lot of unreacted formol, some formic acid and HNO3)....
2) The evaporation/concentration steps are not easy to get rid of water and of the formed formic acid...
3) The isolation step is not easy aswel if you want to isolate the interesting compound that is methylamine...

==> Anyone that has mixed 37% formol with 69% HNO3 knows that runnaway occurs within a few seconds...
The all batch boils into toxic NxOy fumes and accrid / toxic / carcinogenic CH2=O / HCO2H / CO2 / vapour cloud...

So better stick to the safe procedure from NH4Cl and formaldehyde whatever the form... then isolate the methylamine/ dimethylamine and trimethylamine...
Then do the desired salt by conventionnal neutralisation with dilluted acid-base solutions and cristallization by slow evaporation (eventually helped by a precipitating solvent like methanol, isopropanol or ethanol).

joseph6355 - 12-11-2017 at 15:49

Ammonium picrate has a poor oxygen balance (-52).
By mixing it with an oxidizer, will it improve its brisance and VoD?
Assuming that I'll use ammonium nitrate which has an OB of 20, how much should I mix?
Should I simply mix the powdered compounds together?
Which explosive would perform better if I use the same amount for both charges: Ammonium picrate mixed with ammonium nitrate to give a balanced OB or ammonium picrate alone?

PHILOU Zrealone - 13-11-2017 at 05:27

Quote: Originally posted by joseph6355  
Ammonium picrate has a poor oxygen balance (-52).
By mixing it with an oxidizer, will it improve its brisance and VoD?
Assuming that I'll use ammonium nitrate which has an OB of 20, how much should I mix?
Should I simply mix the powdered compounds together?
Which explosive would perform better if I use the same amount for both charges: Ammonium picrate mixed with ammonium nitrate to give a balanced OB or ammonium picrate alone?

The mix will be better...
NH4NO3 --> N2H4O3 --> N2 + 2 H2O + 1/2 O2
NH4ClO4 --> 1/2 N2 + HCl + 3/2 H2O + 5/4 O2
NH4OC6H2(NO2)3 --> C6H6N4O7 --> 3 H2O + 2 N2 + 2 CO2 + 4C

You have to burn 4 C atoms per Ammonium picrate molecule to get the best energy output out of the mix...
This means you need 8 O atoms to make 4 CO2...
==> You thus need 4 times the first equation...
so a molar ratio 1/4 (AmPi / AN)
==> You need 3,2 times the second equation
so a molar ratio of 1/3,2 (AmPi / AP)

The mix would even be better performing with an OB balanced hydrazinium nitrate, hydrazinium perchorate or hydroylaminium nitrate or perchlorate...

The perchlorate variants will always be superior in performances to their nitrate brothers because:
-the density increase is higher,
-the sensitivity towards initiation is higher,
-the energy output per volume will be higher.

I suspect detonic parameters (VOD, brisance) to be into the following order HAP > HP = HAN > HN > AP > AN.
AN will reach the 8-8,4 km/s VOD
AP will reach the 8,4-8,9 km/s VOD
HN will reach the 8,9-9,3 km/s VOD
HP/HAN will reach the 9,3-9,5 km/s VOD
HAP will reach the 9,5-10 km/s VOD

Into such binary mixes of negative OB and positive OB... the resulting mix is always better performing than each explosive appart because each compound provides the best energy output by using at best excess oxygen and excess fuel... what would otherwise be spectator of the detonation wave and only burn (if a fuel) outside the detonation zone...thus later and slower.

A simple mixing will do... but like any binary mixes...the more intimate the mixing, the best...

[Edited on 13-11-2017 by PHILOU Zrealone]

Rocinante - 13-11-2017 at 11:26

If you have a SA.DS/ETN blasting cap with 2 cavities, one central with SA.DS and the other with ETN, which material for the inner tube would be better - 0.3 mm aluminium or 1-2 mm thick plastic (polypropylene)? I'm assuming that the outer tube is made out of paper of plastic.

I'm thinking about combinaition of factors. Will the aluminium fragments present more danger than the 5-7× thicker plastic ones? (this assumes two layers of thick gloves, two layers of face protection, blast mitigation device during assembly). What is the comparative danger of the inner tube breaking during handling? Are there any static electricity considerations with the setup..aluminium/ETN/plastic as opposed to plastic/ETN/plastic or aluminium/ETN/aluminium? I assume that the ETN around the inner tube is only veery lightly pressed, so some amount of material flow can happen and static dicharges during assembly are of no concern (blast mitigation device). I also want to know if there is a significant difference in the amount of primary needed, i.e. 150 mg of SA.DS with the aluminium tube vs. 350 mg for the thicker PP one. Also, how quickly will the 0.3 mm Al fragments lose velocity ... is 30 m enough for it to slow down enough from ~ 2 km/s to only ~ 200 m/s?

joseph6355 - 13-11-2017 at 17:15

Quote: Originally posted by PHILOU Zrealone  
Quote: Originally posted by joseph6355  
Ammonium picrate has a poor oxygen balance (-52).
By mixing it with an oxidizer, will it improve its brisance and VoD?
Assuming that I'll use ammonium nitrate which has an OB of 20, how much should I mix?
Should I simply mix the powdered compounds together?
Which explosive would perform better if I use the same amount for both charges: Ammonium picrate mixed with ammonium nitrate to give a balanced OB or ammonium picrate alone?

The mix will be better...
NH4NO3 --> N2H4O3 --> N2 + 2 H2O + 1/2 O2
NH4ClO4 --> 1/2 N2 + HCl + 3/2 H2O + 5/4 O2
NH4OC6H2(NO2)3 --> C6H6N4O7 --> 3 H2O + 2 N2 + 2 CO2 + 4C

You have to burn 4 C atoms per Ammonium picrate molecule to get the best energy output out of the mix...
This means you need 8 O atoms to make 4 CO2...
==> You thus need 4 times the first equation...
so a molar ratio 1/4 (AmPi / AN)
==> You need 3,2 times the second equation
so a molar ratio of 1/3,2 (AmPi / AP)

The mix would even be better performing with an OB balanced hydrazinium nitrate, hydrazinium perchorate or hydroylaminium nitrate or perchlorate...

The perchlorate variants will always be superior in performances to their nitrate brothers because:
-the density increase is higher,
-the sensitivity towards initiation is higher,
-the energy output per volume will be higher.

I suspect detonic parameters (VOD, brisance) to be into the following order HAP > HP = HAN > HN > AP > AN.
AN will reach the 8-8,4 km/s VOD
AP will reach the 8,4-8,9 km/s VOD
HN will reach the 8,9-9,3 km/s VOD
HP/HAN will reach the 9,3-9,5 km/s VOD
HAP will reach the 9,5-10 km/s VOD

Into such binary mixes of negative OB and positive OB... the resulting mix is always better performing than each explosive appart because each compound provides the best energy output by using at best excess oxygen and excess fuel... what would otherwise be spectator of the detonation wave and only burn (if a fuel) outside the detonation zone...thus later and slower.

A simple mixing will do... but like any binary mixes...the more intimate the mixing, the best...

[Edited on 13-11-2017 by PHILOU Zrealone]

Very interesting.
Is Amatol OB balanced? If it is, why does it have such low VoD and brisance?

greenlight - 14-11-2017 at 04:52

I believe amatol is oxygen balanced, that is the whole reason for its design as well as to extend the amounts of TNT used.
TNT is very underoxidized on its own and this is shown with the black smoke that is visible after detonation. Ammonium nitrate is overoxidized so making a mixture of the two brings the balance closer to 0.

I dont think the VOD is too bad considering it contains the AN which would slow it down a bit.
I can't remember it I will have to have a look when I get home.

EDIT: ANFO 5.8% fuel oil detonation velocity @ 0.82 = 4.55 km/s
AN/TNT 50:50 detonation velocity @ 1.58. = 5.97 km/s
TNT pure @ 1.58. = 6.88 km/s

According to explosives engineering.
It definitely increases the vod a lot mixing the two and thats only in a 50:50 mix which would still be underoxidized.
Could not find exact data for 80:30 or 70:30 mixtures though.




[Edited on 14-11-2017 by greenlight]

Rocinante - 14-11-2017 at 09:12

TNT acts as a thermobaric explosive, Waldemar A. Trzciński measured almost the same positive pressure impulses for RDX/wax 94:6 and TNT. The soot is slightly useful. That's likely why you see TNT eq. of explosives like H-6 cited like only 135 % or 150 % for newer EBX compositions.

[Edited on 14-11-2017 by Rocinante]

greenlight - 14-11-2017 at 19:41

The mixture of just RDX and TNT is not thermobaric.
The Australian C6 composition certainly on the on the edge of thermobaric with the 20%^ Al powder to increase the intensity and heat of the blast wave.

I think the higher vod comes from the large content (^40%) of RDX which is a better performing explosive than TNT.
The thing that makes me think C6 is not a full thermobaric is the fact it is used underwater and has replaced ?torpex? Which I forgot the composition of.
True thermobarica do not function well underwater due to lack of atmospheric oxygen.

Bert - 14-11-2017 at 22:46

Quote:
True thermobarica do not function well underwater due to lack of atmospheric oxygen.


Aluminum (which torpex has a high % of, along with TNT and RDX) reacts just fine with the Oxygen from water vapor, CO and CO2 inside the big bubble formed by an underwater explosion.


20171115_004152.png - 144kB


Thermobaric? Not as I generally see the military use the term, but it DOES make use of environmental Oxygen to after burn a fuel and prolong the pressure pulse. Just not the free O2 in air.


Attachment: Summary of Aluminum Powder Testing.pdf (853kB)
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[Edited on 15-11-2017 by Bert]

greenlight - 15-11-2017 at 09:37

I didn't even think of that Bert.:o
I was always under the impression that thermobarics needed atmospheric oxygen to function properly to develop full pressures.
It must perform quite well underwater in fact if it is used in a formulation especially for torpedoes. Probably due to the extended pressure pulse being good at putting holes in submarines and boat hulls.
Thanks for sharing.

[Edited on 15-11-2017 by greenlight]

Rocinante - 15-11-2017 at 11:49

aluminized explosives tend to burn about 2/3 of its aluminium in its gases (obviously not that great) and only about 1/3 in surrounding air, water vapor is good, though.... underwater charges used aluminium since WWII at the latest, even now they use HTPB/AL/AP/RDX-HMX or TMETN/PCP/Al formulations

within the art there is distinction behind thermobarics, thermobarics that burn most of their aluminium in the air are called thermobarics (TBX), thermobarics that burn most of their aluminium in combustion gases from the nitramine fill are called EBX, enhanced blast explosives. Typical TBX is IPN/Mg 60:40, typical EBX is PBXIH-18 (65 % HMX, 5 % binder, 30 % Al)

FAE are two stage events with mostly ethers, epoxides that are dispersed into the air and detonated via secondary charge (simple iginition won't make DDT that easily)

Bert - 15-11-2017 at 12:12

Failure modes. Not always the scenarios we assume immediately off the cuff.

Aside from the increase in total energy and pressure pulse duration being even harder on air filled things that tons of shock driven, incompressible water hit?

The way to certainly and quickly kill a ship of ocean going size is not usually to punch a hole (water tight compartments, redundant systems, dammage control trained crews and a really BIG structure with lots of reserve bouyancy) but to break it in two. A bigger bubble does this better-


First lift the ship really hard near the middle via an explosion underneath it, not even needing to be in contact with the hull. Then drop it back down onto the remains of the bubble/highly gassed water where the explosion was, which now provides very much less bouyancy due to low density- Ship will be unsupported in the middle, while normal density water supports the ends as per design. SNAP!

Happens to ships naturally sometimes too, when bow and stern are bridged across 2 sufficiently tall and widely spaced waves, leaving the midship insufficiently supported.



[Edited on 15-11-2017 by Bert]

Rocinante - 15-11-2017 at 14:50

it took about 100 kg of TNT exploding 6 m from the hull of a WWII submarine to kill it, submarines were and are hard targets (hulls designed to survive high pressures), so the hunt for powerful explosives was fully justified

greenlight - 16-11-2017 at 09:32

Interesting... So shaped charges would be no good against large boats and submarines then.
I am guessing after the positive pressure pulse/shockwave and gas bubble vacuum created by the explosion there would also be a negative pressure effect as the water rushes to fill the large void too. This would also contribute to damage to the vessel surely.
Like a violent up, down, and then back up motion to the middle of the boat/submarine.



Bert - 16-11-2017 at 09:59

Quote: Originally posted by Rocinante  
it took about 100 kg of TNT exploding 6 m from the hull of a WWII submarine to kill it, submarines were and are hard targets (hulls designed to survive high pressures), so the hunt for powerful explosives was fully justified


Or you could use that HE in a few Hedgehog projectiles

By the end of the war, navies got more sophisticated about both submarine detection and application of high explosive solutions to the submarine problem. Less than 20 kg of HE applied directly to the hull as a shaped charge with an air chamber in front of the cone to allow it to invert properly did the job. Getting the charge where it needs to be beats brute force.

My uncle spent a lot of WWII in a submarine, mostly Pacific theatre. He didn't talk about it much.

[Edited on 16-11-2017 by Bert]

Sandman3232 - 30-11-2017 at 06:07

Anyone know if there is a thread about trinitrobenzene? I've been trying to find one with no sucess. And I cant seem to find much on the internet about it either.

Bert - 30-11-2017 at 06:50

There is a preparation for TNB on Tenney Davis COPAE, to be found in sciencemadness.org library. Data on performance, sensitivity & etc. are given as well. Read chapter 4 FROM THE BEGINNING for a complete explanation on WHY it requires harsher conditions to synthesize and general comparisons of nitro aromatics. TNB article starts pp. 134

Tenney Davis COPAE: You should LOOK HERE before chasing non commercial stuff on Google... Which exists to put adds in front of eyeballs and harvest metadata, not to help little old you actually find stuff out!

More expensive to make in an industrial setting than TNT and has different handling and loading characteristics which make it less attractive from military and commercial point of view, despite somewhat higher VOD and oxygen ballance. More toxic too.

Never made it. Don't know of anyone commercially doing so.



[Edited on 30-11-2017 by Bert]

NeonPulse - 30-11-2017 at 12:17

As far as I can remember TNB is not easily made in an amateur setting. It requires long nitration time and higher temperatures plus obscure nitration agents.

Bert - 30-11-2017 at 17:53

According to Davis, it was easier to synthesize TNT and demethylate that than do the brute force tri nitration of benzene itself.

20171130_185412.png - 722kB

20171130_195433.png - 577kB

greenlight - 30-11-2017 at 21:20

A kilo of fuming sulfuric and half a kilo of 99% nitric per 60 grams of dinitrobenzene!
Over a day at 100C!

It sure takes a lot of bullying to hang that last NO2 group on there.

storing sodium lithium metal in sunflower oil ?

underground - 16-12-2017 at 09:10

Can i store sodium and lithium metal in sunflower oil ? I cant find anywhere mineral oil so i was wondering if just sunflower oil will work. Also do i have somehow to dry it from water or it is not necessary ?

[Edited on 16-12-2017 by underground]

JJay - 16-12-2017 at 09:34

I wouldn't suggest storing alkali metals in any animal or vegetable fats or oils, since they may react, but storing alkali metal under oils is surely better than leaving it unprotected.

The alkali metal will dry mineral oil more effectively than just about anything else... it wouldn't hurt to dry the oil first but this is not necessary for most purposes.

I usually buy mineral oil in the laxative section of the drugstore. You want the kind without any additives.

underground - 16-12-2017 at 09:58

Mineral oil from drugstores here cost about 15€ per 150ml....

JJay - 16-12-2017 at 10:01

It's usually a little less than that here, but I have found it for less than $3 USD per 473 mL shopping around.

underground - 16-12-2017 at 10:17

From what shops you can buy it that cheap?

JJay - 16-12-2017 at 10:20

Walmart.

https://www.walmart.com/ip/Equate-Mineral-Oil-Intestinal-Lub...

[Edited on 16-12-2017 by JJay]

underground - 16-12-2017 at 10:25

I see. Anyway i found tha there is a paraffin oil used as "lamp oil" Is that the same ? It costs 3€ per 1L

JJay - 16-12-2017 at 10:30

If unscented, that would probably work fine for protecting sodium.

underground - 16-12-2017 at 10:45

Yea it is colourless and odourless

Uses for "red water" waste from sulfite wash of TNT?

Bert - 22-12-2017 at 08:28

I recall reading a patent or other process information on reclaiming and recycling into either subsequent batches of TNT (or other explosives synthesis?) the non symmetrical water soluble nitrotoluenes separated from TNT by the sulfite wash process. The "red water" which otherwise would be a loss of fixed Nitrogen, toluene precursor and an environmental hazard If wasted.

A quick Google of this site has not found this again for me, do any recall this being posted here?

[Edited on 22-12-2017 by Bert]

NeonPulse - 24-12-2017 at 03:40

Yeah I think so, I was the one who asked about that - quite some time ago. I had that red water sitting around for ages but only recently got rid of it. I evaporated most of the water and absorbed what was left onto paper towels before incinerating it. As was suggested to me.
I just checked back on that thread and you did mention a process but didn’t have a follow up patent or anything. There was a few other patents there relating to the purification of TNT but I’m unsure if they deal with the recycling of waste water or not I don’t have the time to read through them right now but it is toward the bottom of the page: https://www.sciencemadness.org/whisper/viewthread.php?tid=29...

underground - 10-1-2018 at 18:21

Is there any difference between bubbling Cl gas vs adding hcl acid into a base solution to make a hcl salt ?

SWIM - 10-1-2018 at 18:32

Quote: Originally posted by underground  
Is there any difference between bubbling Cl gas vs adding hcl acid into a base solution to make a hcl salt ?


Yes, because it's Cl gas, not HCl gas.

Cl gas is lousy for making HCl salts because it is lacking in H.

HCl gas works like HCl solution though, as long as it's going into something aqueous.

underground - 10-1-2018 at 22:13

Thank you for your reply but my english are not that good to understund despite i used google translate :D

What do you mean by "lousy" ? Can you give me an example ?

SWIM - 10-1-2018 at 22:21

Lousy is slang for terrible.

Cl is terrible for making hydrochlorides.

HCl is good for making hydrochlorides.

People said lousy a lot 50 years ago but not so much now.

I talk like an old man sometimes, sorry.

joseph6355 - 13-1-2018 at 22:48

How can I obtain small grain-ish crystals that have high density during recrystallization?
The explosive I'm trying to recrystallize is Picric Acid. In fact, its drying outside. I've just filtered it, but the idea of using it as is doesn't make me happy.

I will recrystallize it, but I want high density, but at the same time, small crystals, almost like powder.
I've managed to successfully achieve small crystals by dissolving ETN in hot ethanol and then adding distilled water drop-wise to the solution. The problem is that PA is soluble and recrystallized from water. What should I do, gently boil the water? Crash it somehow in another solvent?
I don't have much time before it dries out. LOL.

ShadowWeirdo - 14-1-2018 at 08:32

Quote: Originally posted by joseph6355  
How can I obtain small grain-ish crystals that have high density during recrystallization?
The explosive I'm trying to recrystallize is Picric Acid. In fact, its drying outside. I've just filtered it, but the idea of using it as is doesn't make me happy.

I will recrystallize it, but I want high density, but at the same time, small crystals, almost like powder.
I've managed to successfully achieve small crystals by dissolving ETN in hot ethanol and then adding distilled water drop-wise to the solution. The problem is that PA is soluble and recrystallized from water. What should I do, gently boil the water? Crash it somehow in another solvent?
I don't have much time before it dries out. LOL.


The faster you boil or dry it, the smaller crystals will be, and the denser it will be. At least we weirdos learned that in chemistry.

nitro-genes - 14-1-2018 at 14:00

Very small scale experiment without much details, but any ideas what was produced? :) Seems an interesting reaction, since it appears to produce a very specific product in, what seems to be, a very good yield.

Had some left over ascorbate and copper(II)sulfate solutions from a DBX-1 synthesis and decided to see if Cu(I) picrate would exist and would be less water soluble than Cu(II)picrate. So I added a spatule of picric acid and ~3 ml 0.4M copper(II)sulfate solution and heated until everything dissolved. Then I added 3 ml of 0.21M sodium ascorbate solution, but nothing precipitated.Thinking that maybe the sodium ascorbate solution had air oxidized, I added 1 drop of very dilute NaCl, immediately producing a white copper(I) chloride precipitate, so Cu(I) was present. Upon adding another 3 ml of ascorbate solution and heating harder to boiling (covered with cling wrap) slowly the solution went to a yellow, then dark greenish brown and finally brown. An abundant yellow-brown precipitate started to form as small (but well defined) crystals. After filtering and drying it is a yellow-brown coloured compound, burning slightly energetic with green flame and producing a lot of carbon (so definitely a picric derived compound). Thinking the colour could be from copper powder, I added a few drops of 70% nitric, which dissolved the compound to a colourless solution (no NOx produced), diluting this with water produced a beautiful bright orange glistening precipitate, barely soluble in water. It melts sharply at around 150-155 deg C. Any ideas? I'm guessing a partial reduction product of TNP itself, but which? :P Alternatively maybe some condensation product of ascorbic or dehydroascorbic and a nitroso/hydroxylamine intermediate (one would think these would be fairly water soluble)?

TNP ascorbate copper(II) reaction.jpg - 72kB

[Edited on 15-1-2018 by nitro-genes]

joseph6355 - 15-1-2018 at 04:46

Quote: Originally posted by ShadowWeirdo  
Quote: Originally posted by joseph6355  
How can I obtain small grain-ish crystals that have high density during recrystallization?
The explosive I'm trying to recrystallize is Picric Acid. In fact, its drying outside. I've just filtered it, but the idea of using it as is doesn't make me happy.

I will recrystallize it, but I want high density, but at the same time, small crystals, almost like powder.
I've managed to successfully achieve small crystals by dissolving ETN in hot ethanol and then adding distilled water drop-wise to the solution. The problem is that PA is soluble and recrystallized from water. What should I do, gently boil the water? Crash it somehow in another solvent?
I don't have much time before it dries out. LOL.


The faster you boil or dry it, the smaller crystals will be, and the denser it will be. At least we weirdos learned that in chemistry.

I must be very stupid. I swear that I've read somewhere that the melting point of PA was 92 C and it would melt.
I just checked COPAE and it states 122 ºC. Thank god.

The batch I synthesized is gone though. I already blew it up.
Thanks and sorry for not double checking it.

Rosco Bodine - 15-1-2018 at 12:35

Quote: Originally posted by nitro-genes  
Very small scale experiment without much details, but any ideas what was produced? :) Seems an interesting reaction, since it appears to produce a very specific product in, what seems to be, a very good yield.

Had some left over ascorbate and copper(II)sulfate solutions from a DBX-1 synthesis and decided to see if Cu(I) picrate would exist and would be less water soluble than Cu(II)picrate. So I added a spatule of picric acid and ~3 ml 0.4M copper(II)sulfate solution and heated until everything dissolved. Then I added 3 ml of 0.21M sodium ascorbate solution, but nothing precipitated.Thinking that maybe the sodium ascorbate solution had air oxidized, I added 1 drop of very dilute NaCl, immediately producing a white copper(I) chloride precipitate, so Cu(I) was present. Upon adding another 3 ml of ascorbate solution and heating harder to boiling (covered with cling wrap) slowly the solution went to a yellow, then dark greenish brown and finally brown. An abundant yellow-brown precipitate started to form as small (but well defined) crystals. After filtering and drying it is a yellow-brown coloured compound, burning slightly energetic with green flame and producing a lot of carbon (so definitely a picric derived compound). Thinking the colour could be from copper powder, I added a few drops of 70% nitric, which dissolved the compound to a colourless solution (no NOx produced), diluting this with water produced a beautiful bright orange glistening precipitate, barely soluble in water. It melts sharply at around 150-155 deg C. Any ideas? I'm guessing a partial reduction product of TNP itself, but which? :P Alternatively maybe some condensation product of ascorbic or dehydroascorbic and a nitroso/hydroxylamine intermediate (one would think these would be fairly water soluble)?

[Edited on 15-1-2018 by nitro-genes]


http://www.sciencemadness.org/talk/viewthread.php?tid=433&am...

Curpous salts and sodium ascorbate are each capable of reducing picric acid to picramic acid.

Picramic acid is the probable reduction product and you could have sodium picramate or free picramic acid depending on pH. Diazotize it and see if DDNP results.

It would be interesting to see if the cuprous / ascorbate system would also partially reduce styphnic acid to provide a diazotization precursor for DDNR. It may work similarly as does the stannous chloride reduction and would be more economical using a cuprous / ascorbate scheme instead of the tin salt. Ascorbate could be useful for recycling regeneration of the spent oxidized metallic salts in either case, and the ascorbate may faciliate use of the metallic salt in catalytic amounts to perform the reduction, with the spent oxidized catalyst being regenerated in situ by incoming additions of ascorbate. This may be done also with iron and manganese salts, and probably cobalt and nickel salts also.

[Edited on 1/15/2018 by Rosco Bodine]

nitro-genes - 15-1-2018 at 13:05

It is some reduction/codensation product, probably immediately precipitated by copper(I) or (II) present, preventig further reaction (Ascorbic is capable of fully reducing TNP IIRC). Picramic crossed my mind as well, it burns fairly similar. Then again, the photo attached doesn't represent the colour right, it is more of a bright orange (like orange peel) instead of the bright red for picramic and although the melting point was taken on a hotplate, it usually is fairly accurate (picramic = 165-170 C) and the compound melted incredibly sharp.

I'll do some more tests, see how the colour changes with changes in pH, solubility in other acids and maybe diazotization indeed.

[Edited on 15-1-2018 by nitro-genes]

Rosco Bodine - 15-1-2018 at 13:07

It is interesting. Try different things and see what results.

Gotta love this basic textbook stuff that for some reason isn't in any of the modern textbooks as specific "student lab" examples particularly for these basic color change pH sensitive dyes.

pH dyes and redox indicators are very cool chemistry all by themselves, and can become essential spectator and reaction condition monitors for a great many other reactions.

[Edited on 1/15/2018 by Rosco Bodine]

Morgan - 15-1-2018 at 14:40

Is there anyplace that sells round metal tubing that is divided in half down the center, something around 3 cm in diameter, more or less? Or what place might use such tubing?
Something like this concept ...
Info if you scroll down to the second photo. This stuff is too small though and it's quartz so a pretty penny too.
http://www.qsil.com/en/products-solutions/twin-an-septum-tub...

[Edited on 15-1-2018 by Morgan]

RogueRose - 15-1-2018 at 17:00

Quote: Originally posted by Morgan  
Is there anyplace that sells round metal tubing that is divided in half down the center, something around 3 cm in diameter, more or less? Or what place might use such tubing?
Something like this concept ...
Info if you scroll down to the second photo. This stuff is too small though and it's quartz so a pretty penny too.
http://www.qsil.com/en/products-solutions/twin-an-septum-tub...

[Edited on 15-1-2018 by Morgan]


What kind of metal? What temps does it need to withstand, any acids/bases? Does it need to be round or can square tube with a divider in the center?

How long does it have to be? Could 2 tubes nested inside one another be possible like 3cm ID of large one and inner one of about 2cm which would give about equal volume of each tube (of the same length) but we'd have to calculate wall thickness of the inner tube for total accuracy.


*Note = Why does it say the word "center" is mispelled on this forum? There are alot of words like this that say that which are not mis-spelled..

Morgan - 15-1-2018 at 20:35

It doesn't have to be anything exotic, it could even be aluminum but preferably some ordinary steel if such a thing exists. Maybe a strip of stiff thin metal could just be slid down a tube as a prototype if the thing would stay in there straight and true. If you could cut a channel on the inside for the strip of metal to fit into on both sides maybe ...

Or cut a slit down one side the length of a tube and slide in a partition flush with the outside walls of tube but seal it from leaking about the cut portion somehow.

I just want to get around using 2 tubes which can't be swagged neatly into a single round hole of a predetermined size. Maybe mash 2 tubes flat on one side and put the two faces together?

I've also considered a tube within a tube with spars or screws to set the spacing but it might create more drag or turbulence for airflow.


nitro-genes - 16-1-2018 at 14:36

Ok, so I made the orange-peel-insoluble-in-water-stuff again, trying to determine better the conditions for it's formation.

0.25 grams (~1 mmole) of picric were added to a 25 ml beaker, together with 0.27 grams of copper(II)sulfate pentahydrate (~1 mmole) and heated in 20 ml of distilled water to near boiling, upon which everything dissolved. NaOH solution was added to a pH of 7 to neutralize the picric. Then I weighed out 0.6 grams (~3.2 mmoles) of ascorbic acid and slowly started adding this to the picric/copper sulfate solution. When about 0.27 g was added (1.5 mmoles), a greenish-yellow precipitate started to form abundantly, the pH at this point was about 3-4. This was filtered off and washed thoroughly. The precipitate was resuspended in 10 ml of water and NaOH solution was again added at room temperature (pH of 10-12 or so), upon which it turned to a deep red-orange suspension. Upon acidifying again (this time using dilute HCl, instead of nitric) the bright orange precipitate formed slowly.

So no reduction to picramic, which would have required at least 6 electrons and 3 mmoles of ascorbic (3.5 if you don't count the copper reduction), though IIRC it's also only able to reduce nitro groups under more basic conditions. Curious what this stuff is exactly though. :)

[Edited on 16-1-2018 by nitro-genes]

nitro-genes - 16-1-2018 at 17:03

Tried recrystallizing some of the orange precipitate from boiling 10% HCl, but it only formed a colourless solution from which nothing precipitated on cooling. When base was added, the orange stuff formed again, though slightly duller in appearance, maybe at high ph it was oxidized again, or the boiling hcl hydrolyzed something off.

Also diazotized some of the orange-peel stuff (after boiling hcl recryst attempt) it immediately formed a yellow compound, flashing like DDNP. Hmmmm, this requires some thinking through of what exactly is the greenish-yellow stuff?! :o

The copper-ascorbic reduction system may be interesting to study it seems. @rosco, you mentioned Cu(I) mediated nitro reductions, any references would be interesting to read.

[Edited on 17-1-2018 by nitro-genes]

Rosco Bodine - 16-1-2018 at 20:27

Copper Picramate is greenish yellow. Picramic acid is the likely reduction product using the copper sulfate / ascorbic acid reagent, where curpous sulfate or hydroxide formed in situ would be reducing towards the copper picrate or sodium picrate also formed in situ.

A double sodium picramate - copper picramate is also a possible product, in any case would be converted to free picramic acid by moderate acid concentration such as added HNO3, and the low solubility free picramic acid would likely precipitate. With further added acid the picramic acid would redissolve via formation of picramic nitrate, so the solubility would be pH dependent....parallel behavior as you have observed for the iso-picramic acid, also showing color changes with pH that mark the transitions in pH where conversions are complete for these amphoteric compounds having changed states and composition.

In the highly acidified state, where the picramic nitrate is dissolved in sufficient excess HNO3 for supplying the NO2 for diazotization as a byproduct from formation of Cu(NO3)2 you could probably add the pieces of copper wire to achieve the diazotization very gradually and get good crystal development.

Using copper acetate with ascorbic acid should also work and eliminate any sulfate impurity. Basic copper carbonate could be easily formed from copper sulfate and filtered out and dissolved in acetic acid or white vinegar.

This is interesting because other divalent salts like iron and manganese and nickel and cobalt should also work, but the economy for the iron and manganese is good.

Should probably get a moderator to export these posts to the DDNP thread.

The picramic from picric thread has a lot of references I'll have to review and see what is already posted to know if I have any other references to add.

https://books.google.com/books?id=PshJAQAAMAAJ&pg=PA407&...

nitro-genes - 17-1-2018 at 03:36

Thanks for looking up the colour of the copper picramate, yellow greenish amorphous matches the precipitate obtained. "Detonates slighty" also sounds interesting. :) I used HCl this time, since unlike HNO3, it is non-oxidizing and doesn't have solvent properties towards nitroarenes like 70% nitric might have, so it indeed seems to behave amphotheric, like would be expected from picramic acid.

Very interesting this, I've attempted the reduction of picric before using ascorbic and catalytic amounts of Fe(II), and didn't get any picramic or precipitate in general. Maybe the copper(I) or (II) is complexing the ascorbic as a ligand in such a way that it forms ideal circumstances to preferentially attack a single ortho nitrogroup, even when the reaction is performed in water, or it may be a property of Cu(I) itself. Would be interesting to test if a catalytic amount of Cu(II) would have a similar effect, guessing not since the copper may be required to precipitate the picramic resulting in a high yield and very pure product. It's possible the acid pH was limiting in the amount of the greenish yellow stuff that was able to form indeed, maybe adding a sodium ascorbate/ascorbic buffered solution at pH of 7 instead of ascorbic acid itself would result in higher yield. Not sure yet the greenish yellow stuff is a copper picramate itself, it may be a different product than that of the first reaction due to a possibly higher pH the first time.

Maybe getting ahead of myself, since this may never exceed the economy of a hydrosulfide reduction, it may however offer some advantages in terms of recycling, waste waters produced and may additionally be advantagous for the reductions of other nitroarenes bearing more sensitive functional groups.

[Edited on 17-1-2018 by nitro-genes]

Rosco Bodine - 17-1-2018 at 13:58

@nitro-genes

Copper picrate has some odd properties and reportedly can decompose in boiling to produce some ammonia and the color of the red orange crystals you show pictured is like ammonium picramate. So there are several possible things going on there. Among the divalent metal salts that could be catalytic in reducing a picrate to picramate iron and copper are both reported. What combinations with ascorbic would work best is unknown, and likewise what proportions and conditions are best is unknown. A set of experiments could be formulated to identify the best process chemistry particulars and optimize the synthesis.

When the synthesis of picramic acid was being first contemplated, ascorbic acid and fructose were both promising reducing agents, also metallic iron and zinc. The observation about Zinin reductions using sulfides requires an alkaline reduction system where the picrate salt is what is being reduced, rather than free picric acid itself being reduced, is a general rule that I think will probably hold true for other reducing agents like ascorbate or fructose or glucose, or the lower oxidation state divalent metal salts as catalysts or reagents.

[Edited on 1/17/2018 by Rosco Bodine]

aga - 17-1-2018 at 15:10

Where would one start with sub-gramme quantities of an EM ?

I've read about many, yet am scared of the whole idea to be honest, so intend to make a remotely controlled micro-lab to at least try, certainly without having any part of me close enough by to be damaged in case it goes wrong.

A big issue (in my mind at least) is how to dispose of the results of Failed experiments.

As it would be sub-gramme, would simply burning the waste ensure that it was not dangerous ?

nitro-genes - 17-1-2018 at 16:19

@aga, You known once you go to the dark side, there is no turning back eh :D The danger involved when working with EM's depends on the specific EM. When working from pre-existing and thoroughly tested syntheses, relatively insensitive EM's, small quantities and with adequate precautions, the danger involved can be largely limited. Starting with picrates might be an idea, they are relatively benign (most biochemistry labs store it as a dye for tissue staining), easy to make, stable in storage and has an interesting chemistry.

@Rosco, there is a lot going on, pH and temperature probably being crucial factors. I haven't been able to produce the pure picramic again (or maybe it was a dinitro nitrosophenol?)...:( This may be far more difficult than I previously thought, and the reactions and precipitates involved seem really puzzling.


Rosco Bodine - 17-1-2018 at 23:01

Quote: Originally posted by nitro-genes  
Ok, so I made the orange-peel-insoluble-in-water-stuff again, trying to determine better the conditions for it's formation.

0.25 grams (~1 mmole) of picric were added to a 25 ml beaker, together with 0.27 grams of copper(II)sulfate pentahydrate (~1 mmole) and heated in 20 ml of distilled water to near boiling, upon which everything dissolved. NaOH solution was added to a pH of 7 to neutralize the picric. Then I weighed out 0.6 grams (~3.2 mmoles) of ascorbic acid and slowly started adding this to the picric/copper sulfate solution. When about 0.27 g was added (1.5 mmoles), a greenish-yellow precipitate started to form abundantly, the pH at this point was about 3-4. This was filtered off and washed thoroughly. The precipitate was resuspended in 10 ml of water and NaOH solution was again added at room temperature (pH of 10-12 or so), upon which it turned to a deep red-orange suspension. Upon acidifying again (this time using dilute HCl, instead of nitric) the bright orange precipitate formed slowly.

So no reduction to picramic, which would have required at least 6 electrons and 3 mmoles of ascorbic (3.5 if you don't count the copper reduction), though IIRC it's also only able to reduce nitro groups under more basic conditions. Curious what this stuff is exactly though. :)

[Edited on 16-1-2018 by nitro-genes]


Try these adjusted proportions for the reduction

Solution A

10 mmole picric acid
5 mmole copper sulfate
10 mmole NaOH

Use sufficient H2O to dissolve at 85C

Solution B

75 mmole NaOH + 63 mmole ascorbic acid

Use sufficient H2O to dissolve at 85C

These proportions should be close to theory

http://www.sciencemadness.org/talk/viewthread.php?tid=433&am...

[Edited on 1/18/2018 by Rosco Bodine]

nitro-genes - 18-1-2018 at 06:08

Why do you assume 6.3 mmoles of ascorbic, instead of half, so 3.15? Sorry if I'm getting this wrong, each mole of ascorbic would be able to donate 2 electrons to form dehydroascorbic right? And if IIRC, reduction of 1 nitro group, 6 electrons would be needed, so 3 moles of ascorbic per mole of picric (unless maybe a pH of >11 (kPa2 of ascorbic) is needed to donate 2 electrons. Another problem that I see is that solution B will have a very high pH, this will precipitate part of the copper as the hydroxide an when reduced by the ascorbic it will result in the insoluble orange-red copper(I) oxide.

[Edited on 18-1-2018 by nitro-genes]

Rosco Bodine - 18-1-2018 at 10:26

I think you may be seeing one of the hydrogens of ascorbic acid as a reducing hydrogen that is actually another different hydrogen "acidic hydrogen" that is tied up in sodium ascorbate.

The copper oxide was expected to be the insoluble end result byproduct that could be filtered from the hot sodium picramate solution. Likewise is iron oxide and manganese oxide ect for the other metal salts used. For the ascorbate reduction that was from earlier research that has not been reviewed again to confirm but there were some literature references checked. You could be right and it would require experiment to confirm. The slight excess ascorbate was provided for offset to air oxidation loss. Likewise the excess NaOH base was to make certain the reduction reaction system is progressing and increasingly basic.

Reviewed the literature and saw the 3 to 1 ascorbate experiments reported lower yields than expected. A color density development in a dilute sample experiment reaction system should confirm the quantity of ascorbate required, and likewise for reduction using fructose or glucose, because the sodium picramate product is such an intense dye that the reaction system functions as its own color indicating analytical test.

[Edited on 1/18/2018 by Rosco Bodine]

aga - 18-1-2018 at 11:53

As for even dipping a toe into the 'Dark Side' i'd clearly be on my own, and at risk :

https://www.sltrib.com/news/2018/01/18/utah-man-who-runs-pop...

Hardly seems that the risk will ever be worth the reward.

joseph6355 - 18-1-2018 at 12:39

Quote: Originally posted by aga  
As for even dipping a toe into the 'Dark Side' i'd clearly be on my own, and at risk :

https://www.sltrib.com/news/2018/01/18/utah-man-who-runs-pop...

Hardly seems that the risk will ever be worth the reward.

I thought that possessing explosives and synthesizing them was legal in the US, with an exception of Acetone Peroxide and some other that I don't remember.

joseph6355 - 18-1-2018 at 12:46

What is the best primary? I know, ambiguous question.
I want a low friction sensitivity but it still needs to make DDT reliably when confined and lit with an open flame coming from a fuse, and it also needs to be storable, it can't decompose with time.
SA(DS) was my first choice, but DDNP also drawed my attention.

Bert - 18-1-2018 at 16:17

Quote: Originally posted by joseph6355  
Quote: Originally posted by aga  
As for even dipping a toe into the 'Dark Side' i'd clearly be on my own, and at risk :

https://www.sltrib.com/news/2018/01/18/utah-man-who-runs-pop...

Hardly seems that the risk will ever be worth the reward.

I thought that possessing explosives and synthesizing them was legal in the US, with an exception of Acetone Peroxide and some other that I don't remember.


In USA, under FEDERAL explosives laws, you can make explosives without a license. But you can NOT store them, use them in any commercial activity, move them on public roads, sell them or even give them away.

There is a culture of fireworks enthusiasts who have figured out how to work around the no storage/transport rules. They start with legal OTC ingredients and can make quite large, complex display fireworks shells in a single long work day. Sacks of chemicals, bottles of 2 part curing rubber/epoxy/polyester or whatever, plastic cans or hemispheres, string, paper, tape, hot melt glue. Some of them even look pretty good in the sky.

Classes are taught in these techniques at PGI conventions, the Western Winter Blast, etc.

https://www.pgi.org/convention/2018/

https://www.westernpyro.org/events


So if you can make it in a day, or better yet, on site- Yes, you are probably good with BATF. But each state and even county, city or township may have their OWN laws in addition to the Federal laws, and good luck on telling them you're OK with the feds if you piss off the local authorities.

It gets confusing. Beyond the several Federal licenses to import, manufacture, deal in or possess explosives, I have held 3 different state's licenses to USE display fireworks, and every one is a bit different.

-----------
(Edit)

The YouTube guy is damned either way.

If he is a legitimate business using explosives and can beat the state possession felony charge by that finding, then his lack of the Federal license(s) he would have needed as a business using explosives will get him a federal felony charge.

It also sounds lime he admitted keeping that sack of powder around longer than the day he got it, and whoever gave it to him also broke the distributing rules.

The dry ice/soda bottle thing is just plain silly, but they have tried to charge high school kids who did that type of experiment IN SCHOOL, WITH A TEACHER KNOWING it was going to be done with legal charges intended by the legislature for terrorism.

It is all fucked up, but slightly better than some other places.

[Edited on 19-1-2018 by Bert]

[Edited on 19-1-2018 by Bert]

joseph6355 - 19-1-2018 at 05:22

I synthesized a new 90 g batch of picric acid from ASA. I just precipitated it and it dissolved it in boiling water. Now its colling down.
I mentioned earlier that I was looking for small grain-ish crystals. but with high purity and at the same time obtaining a high yield from ASA, so I was thinking about simply crushing it with a ceramic pestle and mortar, but under water, or at least wet with cold water.

I really wanted to use picric acid, but big crystals scare me, specially if I want high density, because I would need to press them. If I cant use picric acid, then ammonium picrate will do. Ammonium picrate is way less sensitive to friction and impact, so I was thinking about throwing small amounts in the blender and leaving it there until it breaks down to smaller grains, almost like a powder.
Is it safe to crush picric acid?

[Edited on 19-1-2018 by joseph6355]

Vomaturge - 23-1-2018 at 01:40

Quote: Originally posted by Bert  
Quote: Originally posted by joseph6355  
Quote: Originally posted by aga  
As for even dipping a toe into the 'Dark Side' i'd clearly be on my own, and at risk :

https://www.sltrib.com/news/2018/01/18/utah-man-who-runs-pop...

Hardly seems that the risk will ever be worth the reward.

I thought that possessing explosives and synthesizing them was legal in the US, with an exception of Acetone Peroxide and some other that I don't remember.


In USA, under FEDERAL explosives laws, you can make explosives without a license. But you can NOT store them, use them in any commercial activity, move them on public roads, sell them or even give them away.

There is a culture of fireworks enthusiasts who have figured out how to work around the no storage/transport rules. They start with legal OTC ingredients and can make quite large, complex display fireworks shells in a single long work day. Sacks of chemicals, bottles of 2 part curing rubber/epoxy/polyester or whatever, plastic cans or hemispheres, string, paper, tape, hot melt glue. Some of them even look pretty good in the sky.

Classes are taught in these techniques at PGI conventions, the Western Winter Blast, etc.

https://www.pgi.org/convention/2018/

https://www.westernpyro.org/events


So if you can make it in a day, or better yet, on site- Yes, you are probably good with BATF. But each state and even county, city or township may have their OWN laws in addition to the Federal laws, and good luck on telling them you're OK with the feds if you piss off the local authorities.

It gets confusing. Beyond the several Federal licenses to import, manufacture, deal in or possess explosives, I have held 3 different state's licenses to USE display fireworks, and every one is a bit different.

-----------
(Edit)

The YouTube guy is damned either way.

If he is a legitimate business using explosives and can beat the state possession felony charge by that finding, then his lack of the Federal license(s) he would have needed as a business using explosives will get him a federal felony charge.

It also sounds lime he admitted keeping that sack of powder around longer than the day he got it, and whoever gave it to him also broke the distributing rules.

The dry ice/soda bottle thing is just plain silly, but they have tried to charge high school kids who did that type of experiment IN SCHOOL, WITH A TEACHER KNOWING it was going to be done with legal charges intended by the legislature for terrorism.

It is all fucked up, but slightly better than some other places.

[Edited on 19-1-2018 by Bert]

[Edited on 19-1-2018 by Bert]

I think that, in addition, the ATF has a category of weapons known as "destructive devices" that includes some explosive devices. https://www.law.cornell.edu/uscode/text/26/5845 Destructive devices include :
"(1) any explosive, incendiary, or poison gas (A) bomb, (B) grenade, (C) rocket having a propellent charge of more than four ounces, (D) missile having an explosive or incendiary charge of more than one-quarter ounce, (E) mine, or (F) similar device; (2) any type of weapon by whatever name known which will, or which may be readily converted to, expel a projectile by the action of an explosive or other propellant, the barrel or barrels of which have a bore of more than one-half inch in diameter, except a shotgun or shotgun shell which the Secretary finds is generally recognized as particularly suitable for sporting purposes; and (3) any combination of parts either designed or intended for use in converting any device into a destructive device as defined in subparagraphs (1) and (2) and from which a destructive device may be readily assembled. The term “destructive device” shall not include any device which is neither designed nor redesigned for use as a weapon; any device, although originally designed for use as a weapon, which is redesigned for use as a signaling, pyrotechnic, line throwing, safety, or similar device; surplus ordnance sold, loaned, or given by the Secretary of the Army pursuant to the provisions of section 4684(2), 4685, or 4686 of title 10 of the United States Code; or any other device which the Secretary finds is not likely to be used as a weapon, or is an antique or is a rifle which the owner intends to use solely for sporting purposes."
This seems to apply only to weaponry, but with explosives, "weaponized" might be subjective, and based on intent or the appearance of intent.A bag of sufficiently sensitive and potent explosive could, at least in theory, serve as some kind of weapon by itself. I almost wonder if this specific scenario is a factor in laws against organic peroxide. Of course a bomb, designed to intentionally make shrapnel, with a an attempt to disguise or conceal it, and a trigger mechanism meant to ignite it remotely, would probably be considered a destructive device no matter what. I really don't know whether or not a big homemade firework or an experimental explosive test charge could easily fall into this category, but it might be something to keep in mind.
I'm not a lawyer or an expert in blasting or pyrotechnics by any means, and this law could be a non-issue for things that were not designed as weapons. I thought I'd bring it up here just in case.
Also, your point about state laws is extremely important. Just because something is legal according to federal law does not mean that it will be legal in every state.

[Edited on 23-1-2018 by Vomaturge]

nitro-genes - 23-1-2018 at 09:23

Crystal structure of a copper complex of 2-carboxypentonic acid; A decomposition product of dehydroascorbic acid (Journal of the Chemical Society Dalton Transactions (1987)
DOI10.1039/dt9870002905)

Abstract
In acidic aqueous solution and in the presence of copper(II), ascorbic acid is rapidly oxidized to dehydroascorbic acid, which rearranges to give the branched-chain dicarboxylic acid 2-carboxypentonic acid (1,2,3,4-tetrahydroxybutane-1,1-dicarboxylic acid)(H3cpa). The ion cpa3– is sequestered by copper(II) to produce the insoluble crystalline product [Cu9Cl2(cpa)6(H2O)3]2–·xH2O

This probably explains a lot... :(

Rosco Bodine - 23-1-2018 at 12:49

Depends on the pH of the reaction system what will occur with regards to copper as well as picrate, and dehydroascorbate. It is known that copper can be reduced all the way to the metal by ascorbate. Metal would be a really insoluble product.

Rocinante - 23-1-2018 at 13:06

jioseph: Read this chapter on primary explosives, DDNP is extremely friction insensitive compared to most other primaries but it is more static sensitive, SA.DS, TATP, HMTD are in the same ballpark for friction sensitivity, lead azide and pure silver acetylide are about the most friction sensitive of the bunch, mercury fulminate is between SA.DS and DDNP in terms of friction sensitivity

https://www.sciencedirect.com/science/article/pii/S030438941...

nitro-genes - 23-1-2018 at 16:05

Quote: Originally posted by Rosco Bodine  
Depends on the pH of the reaction system what will occur with regards to copper as well as picrate, and dehydroascorbate. It is known that copper can be reduced all the way to the metal by ascorbate. Metal would be a really insoluble product.


Right as always (well usually)...

Did a couple of tests this evening:

1. 0.25 grams of picric were added to 10 ml water and brought to 80 deg C. Then, 0.6 grams of ascorbic acid were added, which produced no obvious colour change. Using NaOH solution, the picric/ascorbic was adjusted to a pH of around 7, which also did not result in any significant change in colour within 5 minutes. A few crystals of copper(II)sulfate (~5 mg) were added, which immediately produced a clear solution changing rapidly in colour, going from yellow, to orange, to dark orange red, finally resulting in a fine orange-red precipitate at the bottom of the beaker (Seemingly too much to be explained by the copper addition alone, though would need to be weighed). Out of curiosity, another 0.6 grams ascorbic acid was added in small increments (everytime adjusting the solution again to pH7. Strangely, after only a few spatules of additional ascorbic, the solution began producing large amounts of some odourless gas, foaming significantly and changing to a very dark red-orange colour, with only a small amount of precipitate, that most likely is copper powder. The dark red-orange solution was acidified using sulfuric acid, resulting in a much lighter orange solution and a precipitate of brownish crystals, that on closer examination proved to be unreacted picric acid.


2. 0.6 grams of ascorbic acid was dissolved in 10 ml water and brought to around 80 deg C.. Then added a few crystals of copper(II) sulfate, there was no colour change. Then adjusted the solution to pH of 7, which produced a slightly opaque solution with slight orange sheen (Probably copper(I) oxide). A spatule of salicylic acid was added, resulting in no colour change. Finally, a spatule of picric was added, immediately going from orange to dark orange-red again.

It seems copper salts are truly hugely affecting the reduction rate at a pH of 7. Very interesting, the question is what formed here, how specific the reduction is and how the conversion efficiency is (if it can truly acts as a catalyst) Probably not since presumably conversion to copper powder is also happening at this pH and temperature, explaining the unreacted picric recovered.

[Edited on 24-1-2018 by nitro-genes]

Rosco Bodine - 23-1-2018 at 23:26

The copper sulfate / copper hydroxide / copper picrate most probably their "ous" +1 basic salts appears to be functioning as a reduction catalyst, the cupric +2 regenerated to cuprous +1 by the sodium ascorbate. It is the sodium ascorbate solution that should be added gradually.

I'm sticking by what I suggested earlier.

You need to take the acidity of free ascorbic acid out of the reaction mixture by using sodium ascorbate and slight excess base to get the pH distinctly higher maybe 12 doing the entire reduction in an alkaline system. At boiling the end result copper value is likely going to be insoluble copper oxide that can be filtered from a hot supernatant solution of sodium picramate and excess NaOH and sodium dehydroascorbate.

Your brownish crystals you identify as "unreacted picric acid" is likely free picramic acid. Solubility in cold water is extremely low and the microcrystalline material should be as fine as paint or ink pigment, very dull colored like terra cotta or rust not bright canary yellow like picric acid. In basic solution the color should brighten drastically to the blood red dye effect, and bright red color for the sodium picramate salt which is much more soluble and forms coarse reflective crystals. If some of the sodium picramate is dissolved the solution will be intensely red almost black for a concentrated solution that is basic. Neutralized / acidified with acid, the sodium picramate solution will fade as it is titrated to a nearly colorless only very pale yellowish supernatant solution, and the free picramic acid will precipitate as a dull colored extremely fine dust like brown or brown orange precipitate.

I'm betting the reaction is general and will work using copper, or manganese or iron or nickel or cobalt (salts) as the catalyst with sodium ascorbate gradually added to a basic picrate salt solution in a reduction reaction system kept basic. The amphoteric and pH dye indicator property of the picramic acid can be used to track the reaction progress and exploited to isolate the free picramic acid end product.

The picramic acid is analogous to isopicramic acid in its behavior and properties. When a chemically pure picramic and isopicramic acid 50/50 mixture is diazotized according to the special technique for producing higher density crystals of DDNP it is possible a mixed isomer crystal could result having better density than either isomer alone. I think you may have done an experiment with this IIRC, but it was not conclusive what resulted.

[Edited on 1/24/2018 by Rosco Bodine]

JJay - 24-1-2018 at 03:07

Does anyone happen to know if sodium acetate dissolves in acetic acid?

Σldritch - 24-1-2018 at 03:32

It does not, at least not in very concentrated acetic acid.

nitro-genes - 24-1-2018 at 05:11

@Rosco

Fe(0), Iron(II)sulfate (or the hydroxide formed) can also acts as a reducant, I tried once using 7 moles of ferrous sulfate and ammonia at 80 deg C for half an hour. There is reduction going on, judging by the changes in colour and precipitation of Fe2O3, but it is only very small amounts of picramic acid produced, so hardly selective like using hydrosulfides e.g..The Strange thing is that the copper system does seem to have the potential to be very selective for the reduction of 1 ortho nitro group even in aquaous solution. I've made a spatule of very clean DDNP somehow from a spatule of picric, but can't reproduce it. :mad: If the copper oxide/copper indeed needs to be filtered off, it may be beneficial to do the reduction using ammonia, IIRC, ammonium picramate is much more soluble than sodium picramate. This may also help keep the Cu(I) in solution maybe as the diamine complex? Is copper(I)oxide soluble in ammonia? Ammonium picramate solutions may also be more stable at higher temperatures than the sodium one.


JJay - 24-1-2018 at 11:14

Quote: Originally posted by Σldritch  
It does not, at least not in very concentrated acetic acid.


Good to know. I wonder if it is an effective drying agent for concentrated acetic acid.

Rosco Bodine - 24-1-2018 at 13:41

@ nitro-genes

It's Deja Vu all over again. Using ammonia as the base sounds good and reportedly works fine.

I am not sure what solubility is best for a glycine complexed transition metal in alkaline pH but that could be a useful strategy for enhancing the solubility of the catalytic reducing metal.

Manganese nitrate would possibly be a good bet for a candidate, but glycine could be helpful with copper or the others.

http://www.sciencemadness.org/talk/viewthread.php?tid=433&am...

http://www.sciencemadness.org/talk/viewthread.php?tid=433&am...

https://www.youtube.com/watch?v=UMVjToYOjbM

https://www.youtube.com/watch?v=u4xp2lgiAjY

From our recently departed friend RIP Don Haarmann AKA

The Wizard is In

a good read about copper mirror electroless deposition

https://groups.google.com/forum/?hl=en#!msg/sci.chem/t65BM8x...

[Edited on 1/24/2018 by Rosco Bodine]

nitro-genes - 26-1-2018 at 13:03

I was certain the previous run (using only catalytic amounts of copper(II)) produced mostly unreacted picric, even though I was optimistic when I saw the brown coloured crystals too. 1. The precipitate formed only at a pH of <1. 2. Recrystallized from water and together with a pure picric sample on the hotplate, both melted sharply and simultaneously. 3. A comparative burn test between the two behaved exactly the same. 4. Diazotization did not produce DDNP

Addition of ammonia to a picric/copper(II)sulfate solution to adjust the pH did not seem to help at all, it produced a golden coloured precipitate very insoluble, even at higher temperatures, probably some tetra/diamine cupric/curprous picrate or a basic copper(II) tetramine picrate. Anyway, I was able to produce the pure picramic again, keeping the pH slightly basic as you suggested, I need to get all the detials sorted out yet, but after drying the putative copper picramate (air exposure changed the colour, maybe additional reduction or air oxidation of the copper(I)) and redissolving in boiling 10% HCl, upon cooling and dilution beautiful pom grenade coloured needles separate. The copper/ascorbate system seems to have the potential to produce a very high yield as well. Deja-vu or not, this is a remarkable find! I doubt other catalyzing transition metal salts would be able to perform this well, though additional experiments would need to be done to be sure.

It is also interesting whether the copper may be able to catalyze the reduction, my guess is it failed in the last experiment due to the production of copper powder. Maybe changing the addition order, pH or simply running the reduction at a lower temperature may allow the copper to act truly as a catalyst by preventing reduction all the way to metallic copper, which presumably behaves inert.

The selectivity seems to be most interesting to me, even more than the end product, would be really interesting to look at this further and test copper(II) catalysis in combination with other (more economical/green) reducing agents (which would depend on the requisite for precipitation of the copper picramate formed), and may even be of help in removal of polynitrophenols from contaminated waste water for example.

[Edited on 26-1-2018 by nitro-genes]

Rosco Bodine - 26-1-2018 at 13:53

Definitely interesting

All of the transition metals should work to some extent but some are likely to work better than others.

If the manganese salt is tried, the presence of ammonium chloride is reported to inhibit precipitation of the soluble manganese, and a similar effect may occur for other metal salts than manganese, allowing for a greater concentration of the reducing agent and making the reduction go faster and cleaner.

There is going to be an optimum concentration and temperature and pH for this reaction to proceed. The reaction mixture will probably self-regulate at saturation over an excess of reactants in stirred suspension. A bit of guesswork and visual information will guide you. About the addition sequence.....

The reaction system concentration and reduction reaction rate should be rate governed and limited by the addition rate of the sodium ascorbate, keeping a "steady state" maintained for the reduction, but not making addition of the ascorbate too fast so as not to excessively reduce the copper +1 value all the way to the metal, or to accumulate excess cuprous hydroxide, with the idea being to continually refresh the available cuprous hydroxide and maintain its concentration, but not overfeed the ascorbate faster than it is utilized.

The copper +1 cuprous hydroxide is being produced and is the likely reducing agent but is low solubility limited which will rate limit the reduction by its limited concentration.

There are two exit paths from the reduction reaction for the copper catalyst, as the spent oxide which won't be recycled by the ascorbate, or as the metal. And another possible exit path for the copper value is to form the copper salt of the picramate, but I was thinking the sodium salt more likely.

If the reaction is "running out of soluble copper" during the reduction because it is being consumed and is only acting as a quasi catalyst or an inefficient regenerable catalyst being partly regenerated and partly consumed as a reagent, converted to insoluble "spent copper" oxide ....deactivated and precipitated, then a concurrent drip of "makeup" copper value may be needed to replenish the available copper as the reduction proceeds. So long as the reduction reaction mixture is alkaline the makeup copper salt solution with convert to the hydroxide and become available immediately as it is added.

All of these picramic acid related posts need to be exported to the picramic from picric thread.


[Edited on 1/27/2018 by Rosco Bodine]

underground - 27-1-2018 at 15:04

Just a quick question.
Will 2 grams of "X" explosive, with lets assume its VoD is 4000m/s, have the same power or about the same power as 1 gram of "Z" explosive with VoD 8000m/s ?

[Edited on 27-1-2018 by underground]

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