TEX is a recently synthesized explosive that may comply to the very strict property requirements needed for a commercial or military explosive. As an
explosive, TEX is notable for its very high density. Having a measured crystal density of 1.99, TEX has one of the highest known densities of all CHNO
based explosives. This high density is due to its isowurtzitane structure having a close-packed crystal lattice, with the nitro groups occupying the
free space between the cages[1].
TEX is very energetic, combining a high velocity of detonation with low sensitivity to mechanical stimuli and good thermal stability. The
seven-membered rings of the isowurtzitane structure put a strain on the cage and thus increase the energy content of the molecule. A part of the
explosive power of TEX is derived from this cage strain[1]. The insensitive nature of TEX suggests that it may be a suitable high performance
alterative to such explosives as TATB and NTO, thus giving RDX class performance to insensitive compositions[3]. Comparative performance figures for
these explosives is shown in table 1.
<center><img src="http://www.sciencemadness.org/scipics/axt/tex-table.jpg">
<font size="1">TEX: 4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazaisowurtzitane; RDX: Cyclotrimethylenetrinitramine;
HMX: Cyclotetramethylenetetranitramine; NTO: 3-nitro-1,2,4-triazol-5-one; NQ: Nitroguanidine</font></center>
The original synthesis of TEX reported by Joseph Boyer and colleagues[5] involved the nitration of a mixture of
1,4-diformyl-2,3,5,6-tetrahydroxypiperazine (DFTHP) and trimeric glyoxal with mixed 100% nitric and sulphuric acids, a process that required over two
days to complete. This method was found by Highsmith and coworkers to only provide low yields of impure products. It was later discovered and patented
by Highsmith that the nitration of DFTHP to TEX could be done in the absence of trimeric glyoxal, and even in very mild nitrating conditions[10].
The exact mechanism by which TEX is formed from DFTHP is not known, but its believed that strong acids serve to catalyse the formation of the
isowurtzitane structure [10]. The Crude TEX is usually occopanied by some reaction by-products, both lower and higher nitrated derivatives, up to
HNIW. These compounds do not significantly affect the sensitivity or performance of compositions containing TEX[3]. Crude TEX of 97% purity is
described as a pale yellow solid[10].
The precursor, DFTHP, is formed by the condensation of two molecules of glyoxal with two of formamide at pH 9[6,7,9]. Its possible to substitute
formamide with other suitable amines, such as sodium sulphamate to form the analogous disodium-2,3,5,6-tetrahydroxypiperazine-1,4-disulphamate, this
can be nitrated to TEX though reportedly with heavy contamination by reaction byproducts[10]. DFTHP is also the precursor to other highly energetic
explosives such as HHTDD[9] and 1,4-diformyl-2,3,5,6-tetranitratopiperazine[7,8].
<i>1,4-diformyl-2,3,5,6-tetrahydroxypiperazine (DFTHP):</i> 145g (1mol) 40% glyoxal was combined with 45g (1mol) formamide at room
temperature in a 600ml beaker, no increase in temperature was observed. A dilute solution of sodium hydroxide was then dripped into the combined
solution until a pH of 9 was determined by litmus paper. A slow exothermic reaction increased the temperature from 20°C to 50° over ~30 minutes, the
solution turned yellow to orange and a large volume of small white crystals precipitated which solidified the solution (figure 2). The solid solution
was broken up by stirring and left to return to room temperature. The white precipitate was then filtered, flushed with 300ml ethanol and dried to
give 63g (61%) of free flowing white crystals.
<center><img src="http://www.sciencemadness.org/scipics/axt/dfthp.jpg">
<i>Figure 2: Condensation and precipitation of DFTHP</i></center>
<i>4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diaza-tetracyclododecane (TEX):</i> A mixed acid solution was made, comprised of 50g potassium
nitrate and 140g 98% sulphuric acid. The mixed acids were then heated up to 60°C and placed under vigorous stirring via a drill press. 20g DFTHP was
then added in one portion, the solution foamed and gassed as an exothermic reaction raised the temperature to 75°C over ~20minutes (figure 3).
Stirring was continued until the reaction subdued and temperature dropped to 25°C. The solution was then dumped with vigorous stirring into 750ml
cold water which resulted in a very fine, fluffy precipitate (figure 3). The precipitate was then filtered, rinsed with water, then with dilute sodium
bicarbonate, with water again and dried. The very fine mud-like substance (figure 4) was then powdered and extracted with 200ml acetone. Evaporation
of the acetone extract deposited 3.3g of crude TEX as a fine pale yellow powder (figure 4). The crude TEX deflagrated with a hissing flame leaving a
small quantity of black residue and could not be initiated by striking with a hammer on steel.
<center><img src="http://www.sciencemadness.org/scipics/axt/tex-nitration.jpg">
<i>Figure 3: Nitration of DFTHP (left); Fluffy precipitate in water (right)</i></center>
1] K. Karaghiosoff, K; Klapötke, T; Michailovski, A and Holl, G. “4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazaisowurtzitane (TEX): a nitramine with an
exceptionally high density”. Acta Crystallographica Section C; 58, Part 9, 580-581; (2002)
2] Dobratz, B and Crawford, P. "LLNL Explosives Handbook - Properties of Chemical Explosives and Explosive Simulants" Lawrence Livermore National
Laboratory. California. (1985)
3] Lund, G; Highsmith, T; Braithwaite, P; Wardle, R. “Insensitive High Performance Explosive Compositions”. US patent #5529649. (1996)
4] Zemen, S. “New Aspects of Impact Reactivity of Polynitro Compounds. Part IV. Allocation of Polynitro Compounds on the Basis of their Impact
Sensitivities” Propellants, Explosives, Pyrotechnics; 28; No. 6; (2003)
5] V. T. Ramakrishnan, M. Vedachalam, and J. H. Boyer, Heterocycles; 31; 479; (1990)
6] Sidney, V.; Clifford, M. and Barker, R; “The Formation of N,N'-Dihydroxyethylenebisamides from Glyoxal and Selected Amides” Journal of Organic
Chemistry; 30(4); 1195-1199; (1965)
7] Ferguson, A and Fort, G. “Piperazine Derivatives” GB patent #1045905 (1965) and “1,4-Diformyl-2,3,5,6-Tetrahydroxypiperazine and Derivatives
and Preparation Thereof” US patent #3365454 (1968)
8] Karaghiosoff, K. et. al.;. “1,4-Diformyl-2,3,5,6-Tetranitratopiperazine: A New Primary Explosive Based on Glyoxal” Propellants, Explosives,
Pyrotechnics; 28; No. 1; (2003)
9] Vedachalam, M.; Ramakrishnan, V.; Boyer, J.; "Facile Synthesis and Nitration of cis -syn -cis -2,6-Dioxodecahydro-1H,5H-diimidazo[
4,5-b:4’,5’-e]pyrazine", Journal of Organic Chemistry; 56; 3413-3419 (1991)
10] Highsmith, T., Edwards, W and Wardle, R; “Synthesis of 4,10-Dinitro-2,6,8,12-tetraoxa-4,10-Diazatetracyclo[5.5.0.05,903,11]-Dodecane”. US
patent #5498711 (1996)
[Edited on 12-6-2006 by Axt]kazaa81 - 11-6-2006 at 05:35
Is glyoxal avaible to the average chemist amateur?
Apart reagents, the page you've wrote is very clear! Axt - 11-6-2006 at 06:36
Quote:
Originally posted by kazaa81
Is glyoxal avaible to the average chemist amateur?
There should be no restrictions on glyoxal, though there might be on formamide.The_Davster - 11-6-2006 at 10:33
Glyoxal seems to be pretty damn usefull, HNIW, TEX, furazans, and many others which I have read about. It has been on my 'to get' list for quite
some. I should get my act together now and get some.
As always, nice work Axt
old glyoxal
acetate - 11-6-2006 at 11:08
Very nice article
... anybody know what contain old 40% solution of glyoxal(yellow solution with white precipitate) ?IPN - 11-6-2006 at 11:47
The white precipitate is most likely just polyglyoxal, this can be converted to anhydrous glyoxal through distillation with P2O5. Polyglyoxal should
also depolymerize under simple heating though it decomposes if heated above 150C.
The yellow color of the solution is normal and nothing to be worried about.Vitus_Verdegast - 11-6-2006 at 12:44
Quote:
There should be no restrictions on glyoxal, though there might be on formamide.
Formamide is used in the Leukart-Wallach reductive amination of phenylacetones to amphetamines and is watched almost everywhere in the civilised world
for its role in the (large-scale) production of the controlled substances amphetamine and MDA.
It can, however, be prepared by heating ammonium formate beyond its decomposition temperature.
[Edited on 11-6-2006 by Vitus_Verdegast]garage chemist - 11-6-2006 at 13:42
Good work, Axt. I haven't heard of this substance before. Where did you hear about it?
About Formamide: Has anyone tried out the decomposition of ammonium formate to obtain formamide?
The problem I see with this is that formamide cannot be distilled at normal pressure, since it decomposes ( boiling point of above 210°C, decomposes
there).
It might be necessary to decompose the ammonium formate in a vacuum distillation setup- but then one would have to redistill the formamide (in vacuum
too), since the entire reaction water would end up as mixture with the product. And wouldn't the ammonium formate partially sublimate?
I made some formamide once by reacting ethyl formate with ammonia solution (analogous to the preparation of acetamide from ethyl acetate and ammonia).
I was very surprised as there was a strong exotherm and rapid homogenization of the reaction mixture upon mixing, much unlike acetamide, which takes
several days to complete.
The water and ethanol were then distilled away (at ordinary pressure), leaving the formamide.
But ethyl formate is too expensive and precious for this use, hence the need for an alternative process starting from ammonium formate.Vitus_Verdegast - 11-6-2006 at 13:54
When temp reaches +- 200°C and reaction is mostly over, one could perhaps vac distill it from there?
[Edited on 11-6-2006 by Vitus_Verdegast]chemoleo - 11-6-2006 at 15:34
Awesome!
What strikes me is the bad yield though - 3.3 g from 20 g of the DFTHP.
Still the high yield of DFTHP is fantastic, I didnt realise this ws such an easy and efficient reaction.
Are you going to try to make the tetranitro derivative? I am suspecting that the trifluoroacetic anhydride presence wont be strictly necessary for the
nitration, unless H2O destroys the intermediate products. But then I don't see why any other strong water scavenger wouldn't do.
The tetranitro derivatives are in ref 7,8 above, and here: https://sciencemadness.org/talk/viewthread.php?tid=506
Also, the CHO moieties look fantastic for further substitutions...hydrazine, carbazides, etc etc come to mind.Axt - 12-6-2006 at 03:52
Quote:
Originally posted by garage chemist
Good work, Axt. I haven't heard of this substance before. Where did you hear about it?
It rates a fair mention in a lot of the recent reviews of energetic materials. Just followed references from there.
Quote:
Originally posted by chemoleo
What strikes me is the bad yield though - 3.3 g from 20 g of the DFTHP.
That was the best yield I got, and I did it numerous times. There is a lot of differeing conditions in the examples of the patent, I tried simply 70%
HNO3 as in patent with no yield, also with 70%HNO3/H2SO4 again yielding nothing but a water soluble product. Its a really crappy fine precipitate in
water and very annoying to filter.
Quote:
Originally posted by chemoleo
Still the high yield of DFTHP is fantastic, I didnt realise this ws such an easy and efficient reaction.
Its easy 'cause DFTHP has very low solubility in water.
Quote:
Originally posted by chemoleo
Are you going to try to make the tetranitro derivative? I am suspecting that the trifluoroacetic anhydride presence wont be strictly necessary for the
nitration
I dont think I'll try, trifluoroacetic anhydride is in the PEP article and a huge excess of 100% HNO3/acetic anhydride in the patent. H2SO4 or oleum
yield TEX. so it doesnt look like an easy thing to get to, maybe try P2O5/HNO3 but if you had that you'd be making HHTDD instead.
[Edited on 12-6-2006 by Axt]IPN - 12-6-2006 at 04:09
P2O5 isn't that hard to get so the tetranitro derivative might be an interesting thing to try out. That and HHTDD.
Axt, could you upload those articles to rapidshare or something similar? Would be nice to read them for extra info.Axt - 12-6-2006 at 04:26
As before I'll try find them all again. Though I dont have [5] and could only get [1] from a google cache. And you should already have the PEP ones
[4,8]. If you take away the patents [3,7,10] and also HHTDD article [9] which I already attached <a
href="http://www.sciencemadness.org/talk/viewthread.php?tid=5997">here</a> and I aint scanning in the book [2]. That leaves [6] which isnt
very interesting anyhow hahah!
OK .. I'll zip them Polverone - 12-6-2006 at 19:16
Nice work as usual. Give it a look-over here: https://www.sciencemadness.org/member_publications/TEX.pdf. The table is currently missing. It's complicated enough that I don't want to try to
recreate it myself, but the version you uploaded is a bit low-resolution. I don't know what you made the table in, but can you save and upload a
higher resolution version that I could put in the document?Axt - 12-6-2006 at 22:00
I cant see any problems with the pdf, as for the table... hmmmm...
But I suspect the problem is that your program wants to resize the image when its inserted?, thus losing the fine lines. I dont think I can fix that.
I did it in HTML then did a screenshot, I can make it smaller if that would help, but it looks like it should fit as is. http://rapidshare.de/files/22927944/table_sm.html.html
[Edited on 13-6-2006 by Axt]Polverone - 13-6-2006 at 16:47
Thanks for the HTML original. It looked fine on screen even with the old table; I wanted a higher resolution version so it would look good when
printed. I was able to take a larger screenshot from your HTML. You can look at the updated PDF now.
