Sciencemadness Discussion Board

What is the actual mechanism for HMTD?

killswitch - 21-4-2013 at 09:38

The mechanism for the formation of acetone peroxide (dimer and trimer) are relatively simple. From what I understand, they're just the radical polymerization of the geminal diol hydrated form of the ketone, initiated by hydroxyl radicals from the peroxide. A first-year (though maybe not first semester) organic chemistry student could draw a step-by-step diagram of the entire reaction.

But for hexamethylene triperoxide diamine, formation of the peroxide requires scission of amine-methylene bonds. How exactly does that occur under the given conditions, and what limits the formation of hexamethylene chloride or citrate and the hydrolysis to formaldehyde and ammonia?

And is it true that the three-dimensional structure of HMTD resembles a continuation of the adamantane motif, but with one bond at each vertex on the joining face replaced by a lone pair? Actually building the thing out of a MolyMod plastic kit showed me just how strained the molecule actually is, assuming I built it correctly. The geometry is beautiful, but damn if that isn't a lot of lone pairs forced to face each other.

AndersHoveland - 21-4-2013 at 15:32

I have wondered why the nitrogens do not get oxidized to the N-oxide.
For example, H2O2 oxidizes trimethylamine to trimethylamine N-oxide.

killswitch - 23-4-2013 at 05:46

In related news, researchers have discovered that red meat causes hardened arteries due to the presence of gut flora that digest carnitine to trimethylamine. TMA is oxidized in the liver to the N-oxide, which is a known atherosclerotic.

[Edited on 23-4-2013 by killswitch]

Fantasma4500 - 23-4-2013 at 08:03

actually never thought about hexamine and hcl, why doesnt it react when mixed..?? or perhaps it does?
weird
perhaps its lacking concentration of HCl?

perhaps try in mL scale on a very sturdy glass plate or something alike to mix equal amounts of hexamine, concentrated H2O2 and HCl
perhaps in different ratios
or try to see if hexamine can react with hcl at all in low concentrations.. i think this might be what stops it from happening..
now that i think of it..
you use citric acid with hexamine, but im very sure ive seen it made with hcl aswell?

Adas - 23-4-2013 at 11:29

Quote: Originally posted by Antiswat  
actually never thought about hexamine and hcl, why doesnt it react when mixed..?? or perhaps it does?
weird
perhaps its lacking concentration of HCl?

perhaps try in mL scale on a very sturdy glass plate or something alike to mix equal amounts of hexamine, concentrated H2O2 and HCl
perhaps in different ratios
or try to see if hexamine can react with hcl at all in low concentrations.. i think this might be what stops it from happening..
now that i think of it..
you use citric acid with hexamine, but im very sure ive seen it made with hcl aswell?


Some people make HMTD with HCl and say it works very well.

chemcam - 23-4-2013 at 14:54

I have tried in the past using HCl and never got the desired HE product, I tested small sample with hammer and fire to be sure. I end up with ammonium chloride crystallizing out and a bright neon-like yellow/green colored solution of something. I would guess the H2O2 caused the color by oxidation of?



-------------------------
I have however hydrolyzed hexamine with HCl to get ammonium chloride and formaldehyde, that reaction produced a clear solution. This is a preparation I will not do again without a strong fume hood. So yes, hexamine and HCl definitely react.

virgilius1979 - 24-4-2013 at 10:26

I've tried both citric and HCl; HCl works as well, but you need to keep an eye on temperature, as it rises more than if you use citric acid.
H2SO4 should be diluted first, not to be used concentrated, as the reaction is highly exothermic.

kratomiter - 25-4-2013 at 01:36

This week I tried making some HMTD (first time) without succes.
I keep temperature under 0C, mixing 14 g pure hexamine in 50 ml 35% H202.
I tried with HCl, Acetic Acid, nitric, sulphuric... Neither give any HMTD, but there are people getting good yields with HCl.
A magnetic stirrer is a must?
I realized that hexamine and HCl reacts at higher temperatures, giving a strong formaldehyde odor.

virgilius1979 - 25-4-2013 at 09:37

There are already many threads about this. UTFSE !
Your hexamine might be contaminated, or you're not controlling the temperature.

AndersHoveland - 25-4-2013 at 09:58

Quote: Originally posted by Antiswat  
actually never thought about hexamine and hcl, why doesnt it react when mixed..?? or perhaps it does?

It does react, it simply forms the salt hexamine di-chloride. Apparently higher concentrations of acid can cause the hexamine to disproportionate into methylamine salts and formic acid, but from what I have read, this generally requires temperatures above 90°C.
http://www.erowid.org/archive/rhodium/chemistry/methylamine....


Actually, this could potentially explain why the nitrogen do not get oxidized. They are protonated. By the time the solution is neutralized, the H2O2 is also gone. I wonder if it is possible to oxidize HMTD to the N-oxide with H2O2 at neutral pH, or whether that would cause the product to be destructively oxidized/hydrolyzed.

[Edited on 25-4-2013 by AndersHoveland]

chemcam - 25-4-2013 at 10:11

Quote: Originally posted by kratomiter  
This week I tried making some HMTD (first time) without succes.
I keep temperature under 0C, mixing 14 g pure hexamine in 50 ml 35% H202.
I tried with HCl, Acetic Acid, nitric, sulphuric... Neither give any HMTD, but there are people getting good yields with HCl.
A magnetic stirrer is a must?
I realized that hexamine and HCl reacts at higher temperatures, giving a strong formaldehyde odor.


I know these threads on HMTD are everywhere so I'm only going to say a few necessary things.
If you like your fingers, hands, arms, upper torso, your life then I would not make so much, 14g, that is a hell of a lot. It is so much safer and smarter to make a maximum of couple grams each time. What will happen is you will have a HUGE pile, then you will take a small sample to test friction/shock, it will surprise you how sensitive it is, then you will be scared to go near your pile, and have a hard time disposing it. Maybe you have a death with, I don't know. HMTD and TATP are very similar in stability and safety. Just be aware, I'll stop being a wet towel now. If this is your very first HE you may want to reconsider and find one which is a little more stable and forgiving.

I see one flaw to your synthesis you wrote in addition to not having the preferred acid. If you really want help post the ENTIRE procedure step-by-step exactly what you did.

Adas - 25-4-2013 at 10:48

Quote: Originally posted by AndersHoveland  
Actually, this could potentially explain why the nitrogen do not get oxidized. They are protonated. By the time the solution is neutralized, the H2O2 is also gone. I wonder if it is possible to oxidize HMTD to the N-oxide with H2O2 at neutral pH, or whether that would cause the product to be destructively oxidized/hydrolyzed.

[Edited on 25-4-2013 by AndersHoveland]


Remember that not every nitrogen in organic compounds can be oxidized. And I would assume that HMTD is too resistant towards oxidation + it is insoluble.

kratomiter - 27-4-2013 at 09:22

Thank you everyone, I got a good yield with just 5 mL HCl 20% more.

chemcam - 27-4-2013 at 09:32

Quote: Originally posted by kratomiter  
Thank you everyone, I got a good yield with just 5 mL HCl 20% more.


Can you post your whole process, I'd like to see it since I have never gotten it to work without citric acid and are you sure what you got is HMTD have you tested it yet?

killswitch - 29-4-2013 at 08:27

What solvents dissolve HMTD?

Adas - 29-4-2013 at 10:12

Quote: Originally posted by killswitch  
What solvents dissolve HMTD?


There are no solvent that can dissolve HMTD easily, AFAIK.

killswitch - 30-4-2013 at 05:43

Quote: Originally posted by Adas  
Quote: Originally posted by killswitch  
What solvents dissolve HMTD?


There are no solvent that can dissolve HMTD easily, AFAIK.


Looking at it, it seems like a weak base with a band of high electron density at the center, surrounding the peroxide bonds. It seems like it would be only weakly polar, if at all.

So, an aprotic, mildly electrophilic, weakly polar liquid? Maybe nitromethane, or something similar?

Of course, another route would be to form a quaternary salt, but... Jesus Christ. I wouldn't be surprised if such a thing matched lead azide crystals in sensitivity.

Though I guess if you're in it for the chemistry, you could try something crazy like HMTD nitrate or HMTD picrate, but I wouldn't want to make much more than is necessary to be seen with the naked eye.

killswitch - 30-4-2013 at 06:30

Now, when I said I wanted the mechanism, I meant a step-by-step. Something like this, which I assume is the TATP reaction. I drew it in ChemDoodle:

kratomiter - 30-4-2013 at 13:31

Quote: Originally posted by chemcam  
Quote: Originally posted by kratomiter  
Thank you everyone, I got a good yield with just 5 mL HCl 20% more.


Can you post your whole process, I'd like to see it since I have never gotten it to work without citric acid and are you sure what you got is HMTD have you tested it yet?


First I cooled down to -10ºC 50 mL H2O2 35%, then added 14 grams Hexamine.
After stirring and keeping the solution in an ice bath, I drop 10 mL HCl 20%.
No precipitated was formed after 6 hors, so I took out the solution form the ice bath.
After around 8 hours at room temperature, no precipitated was formed.
I tried adding 5 mL HCl 20% more... I just 20 min I had a lot of cristals, so I didn't wait long and filtered them.

Yes, it seems to be very pure HMTD and deflagates without no residues left.
I detonated with it MHN, even p-mononitrotoluene and commercial MEK peroxide.

chemcam - 30-4-2013 at 16:45

Thanks, even when I use citric acid I don't get any crystals until I remove the flask from the ice bath and the temp rises to room temp. That's when they always fall out I guess.

killswitch - 2-5-2013 at 08:52

So does anybody know the reaction mechanism or is this thread going to be synthesis questions by third parties?

I had this same problem trying to get the equilibrium constant for the nitration of glycerin.