Sciencemadness Discussion Board

dimethylammonium perchlorate

woelen - 25-1-2015 at 11:07

I recently purchased 250 ml of dimethylamine 40%, dissolved in water. My first experiment with this is making the perchlorate salt of this and checking its energetic properties.

I mixed a solution of appr. 30% HClO4 with a slight excess of the solution of dimethylamine. The excess was such, that after mixing, the liquid still had a clear smell of the dimethylamine. I wanted to be sure that no excess perchloric acid remains, because that would make it impossible to get dry material after evaporating of the water.

Next, I boiled down the solution, until most of the excess dimethylamine was driven off and then I put it in a warm dry place (appr. 40 C, on top of a boiler, free of dust).
It took a few days before solid material was obtained. I broke the material into smaller pieces and allowed the material to dry further for another 2 days. Then I collected the material and put it in a small well sealed vessel. The material is white and somewhat hygroscopic.

This material has the funny property that it explodes on heating, even when only very slightly confined. The explosion in that case is quite impressive.

I took just 10 cubic mm or so of the dry material and put this in a dry thick-walled test tube. This test tube was heated above the flame of a small alcohol burner. It fizzled a little bit and then it suddenly exploded with a weak orange flash and a very loud report. After the explosion, inside the test tube there were small droplets of a brown liquid, probably charred material.

What I found particularly surprising was the force of the explosion. There was no real confinement of the small amount, it just was sitting at the bottom of the test tube.

I also tried heating a small amount of the solid on a metal spatula in a flame. If this is done, then it fizzles for a few seconds and then suddenly deflagrates with a purple/pink flame, associated with a loud hissing, sometimes crackling, noise.

[Edited on 25-1-15 by woelen]

PHILOU Zrealone - 26-1-2015 at 02:35

Most perchlorate amine are sensitive and powerful explosives...especially if close to zero Oxygen Balance.
The ease of preparation and safety involved makes it a good choice with comparable performances as the best HE but shock/friction/heat sensitivity is sometimes high (although less than NG) what makes it easily detonable.

Typical examples are:
(some of which you have beautifully characterized and presented in your website)
-Hydrazine perchlorate or diperchlorate (way too oxygenated) but might be interesting in perfect OB mixes with other negative OB amine perchlorate of the familly
-Hydroxylamine perchlorate (also over oxygenated)
-Hexamethylenetetramine diperchlorate and triperchlorate
-Methylamine perchlorate
-Hydroxylaminomethyl perchlorate (CH3-NHOH.HClO4 and CH3-O-NH2.HClO4)
-Ethylenediamine diperchlorate
-Guanidine perchlorate
-Biguanidine diperchlorate
-Cyanoguanidine perchlorate
-1.3.5-triaminobenzene triperchlorate
-Trimethylamine-N-oxyde perchlorate
-glycine perchlorate

There are zillions of unexplored HE perchlorates
-TATNB perchlorate or diperchlorate?
-DABCO diperchlorate
-DABCO di-N-oxyde perchlorate or diperchlorate
-polyvinylamine perchlorate
-Hexamethylaminebenzene hexapechlorate

Usually perchlorate of amines vs the nitrate variant are:
-more powerful
-better OB
-higher VOD/lead block tests
-easier to detonate
-more shock/friction sensitive
-do form nicer cristals (sometimes anhydrous, but sometimes very deliquescent and hygroscopic)

Sole drawbacks, but are they really one?
-toxic HCl fumes
-corrosive fumes
-slighly more expensive (although HClO4 is accessible via chlorate cell and chlorate-perchlorate dismutation)

The detonic of such halogenated compounds is less studied than CHNO explosives, but it might be interesting to compare perchlorate vs perbromate vs periodates (with due caution ... see the uncompatibilty between hydrazine and periodic acid and the very high oxydation potential of perbromic acid what may renders some to be unpractically sensitive).
Because the anion change will probably make big density jumps and density is a key factor in detonic; the brisance parameters of such salts might be very interesting :D but maybe not the propelling parameters :(

[Edited on 26-1-2015 by PHILOU Zrealone]

woelen - 26-1-2015 at 04:39

I wish I also had methylamine. The compound methylammonium perchlorate has nearly perfect oxygen balance and must be quite interesting to experiment with:

CH3NH2.HClO4 --> CO2 + 2H2O + HCl + ½N2 + [H]

Only one H-atom is unbalanced. Another nice thing is that the compound will leave nearly only gaseous remains at the temperature of decomposition.

Unfortunately, I can only buy methylamine 40%, dissolved in water, by the liter and a liter of this stuff is quite expensive (well over EUR 60). I have not found any seller who sells 100 ml or maybe 250 ml.

Mailinmypocket - 26-1-2015 at 05:17

This procedure works quite nicely for preparing small amounts of methylamine. All you need is some acetamide which is very easy to make or buy.

PHILOU Zrealone - 26-1-2015 at 05:46

Methylamine can be done by reduction of nitromethane, and from methyl iodide in exces aqueous ammonia.
Must be also possible with methanol in exces aqueous ammonia with help of a catalyst and by reduction of CH2=NH (formaldehyde and amonia).
Maybe by heating a mix of ammonium formate and formaldehyde....

It is part of the thermohydrolysis products of hexamethylenetetramine hydrochloride besides dimethylamine and trimethylamine hydrochloride...the CH2=NH is reduced by formaldehyde or formic acid into does CH3-N=CH2 that yield (CH3)2NH...

[Edited on 26-1-2015 by PHILOU Zrealone]

franklyn - 26-1-2015 at 09:18

Another way to the adduct is to blend Dimethylamine with Ammonium Perchlorate to displace the ammonia.

5 (CH3)2NH + 5 NH4ClO4 => 5 (CH3)2NH•HClO4 + 5 NH3 ^

This method was discussed in several posts following my post here with regard to solvent effects.

Dimethylamine Perchlorate blended with excess Ammonium Perchlorate is an oxygen balanced blasting composition

5 (CH3)2NH•HClO4 + 7 NH4ClO4 => 10 CO2 + 28 H2O + 12 HCl + 6 N2

This can be achieved in one step by adding 9 parts by weight of Dimethylamine to 19 parts by weight of Ammonium Perchlorate,
which is a very slight excess of Ammonium Perchlorate. ( stoichiometric ratio is 45 : 94 )

5 (CH3)2NH + 12 NH4ClO4 => / + 5 NH3 ^ / + 10 CO2 + 28 H2O + 12 HCl + 6 N2

Safe-handling perchlorate explosives
US 3864177 ( patent ) recommends solvents to render insensitive.

Encyclopedic Information on Dimethylamine

AJKOER provided this link for a Methylamine synthesis procedure in the last post of the other thread I cited above.

See :
6) Synthesis of Acetamide from Acetic Acid and Urea
3) Synthesis of Methylamine/Methylamine HCl via Hofmann Rearrangement


Reacting Dimethylamine with formaldehyde gets you Bis(dimethylamino)Methane
The supposed perchlorate salt adduct has poor oxygen balance but huge molar gas volume.
(CH3)2N.CH2.N(CH3)2•2 HClO4 => 5 CO + 3 H2O + 2 HCl + N2 + 4 H2

Similar to Hexamine dinitrate or diperchlorate as observed before.

[Edited on 27-1-2015 by franklyn]

PHILOU Zrealone - 26-1-2015 at 11:46

Quote: Originally posted by franklyn  
Reacting Dimethylamine with formaldehyde gets you Bis(dimethylamino)Methane
The supposed perchlorate salt adduct has poor oxygen balance but huge molar gas volume.
(CH3)2N.CH2.N(CH3)2•2 HClO4 => 5 CO + 3 H2O + 2 HCl + N2 + 4 H2

Similar to Hexamine dinitrate or diperchlorate as observed before.


Very nice finding franklyn,

I will try to calculate explo-physical parameters for those salts.
And the putative dinitroformiate salt aswel!

It is possible that the diperchlorate is as difficult to get as the tetra- or tri-perchlorate of hexamine.

Main problem in hexamine is the close vicinity of each pair of two amine groups and the coexistance of two charged N(+) atoms spaced by one CH2

[Edited on 26-1-2015 by PHILOU Zrealone]

Arcuritech - 26-1-2015 at 12:51

How about urea perchlorate? Simple preparation (assuming you have perchloric acid) and if the nitrate analog is anything to go on it should work quite well.

franklyn - 29-1-2015 at 20:02
Warnings on these type compounds