This months issue of the Journal of Propellants, Explosives, and Pyrotechnics has a paper submitted by Phil Eaton, the chemist who first synthesized ONC a year or so ago, about his latest research. He concluded that octanitrocubane is a huge disappointment. The experimentally determined properties of ONC do not match with what theory said it would, specifically its density. This means ONC is not nearly as explosive as they thought it would be. Oh, there may still be some unfound crystalline structure that may have a higher density, but he thinks it will never be quite so cheap to manufacture, nor perform quite so well as the nearest runner up, heptanitrocubane.

Yes, HpNC is the newest top dog on the block. It is considerably easier to synthesize than ONC (it is the starting material for it too), it has a greater density, it is very stable, etc etc. Too bad it is rather difficult to synthesize. I am not saying it is impossible, even for the home chemists at The Forum, but there is a steep materials curve.

The earlier synthetic required you start with tetranitrocubane, TNC, (a powerful explosive in it’s own right likely to be a close second to HpNC especially in light of this reaction) mixed in THF which is frozen on a glass plate to around –75 °C while frozen N₂O₂ is sprinkled on top. When the surface of the glass is slowly allowed to warm up a reaction takes place and you get pentanitrocubane. This very same reaction is continued to make hexanitrocubane (starting with the penta), and then heptanitrocubane (from the hexa). I believe N₂O₄ forms when you cool NO₂ gas to below its boiling point, 21.15 °C and it freezes at –9 °C.

I know that may seem like it is a bit difficult, but you can get a freezing bath this low with dry ice ,CO₂ and acetone (-86 °C). You can sub acetone with either alcohol (-72 °C), chloroform (-77 °C), ether (-100 °C), or by itself (-78.5 °C). The real challenge is getting enough of this stuff to matter at a price that will not break the bank.

A better way to get HpNC in one batch, but still a bit more complex considering the starting materials is to mix TNC with NaN(TMS)₂. Specificially, you stir in the NaN(TMS)₂ to the TNC in a 1 to 1 mix of THF and a-methyl THF (solvent mix) cooled to –78 °C. This will form a sodium salt (how this is determined I do not know), then the mix is cooled to between –125 °C and –130 °C where a viscous fluid forms. With vigerous stirring, N₂O₄ in cold isopentane is added to the fluid, after 1 minute the mix is quenched with a mixture of nitric acid in cold ether. Finally the whole damn thing is dumped into water. The less NaN(TMS)₂ you use, the more penta- and hexanitrocubane you will get, HpNC requires at least 4 equivalents the molar mass of TNC (an excess).

The reaction scheme...
<img src="http://www.roguesci.org/hpnc_rxn.jpg" alt="" />

Incidentally, you cannot synthesize octanitrocubane from either above reaction. Now then, wherever shall I get my hands on some NaN(TMS)₂? Except for the cold temperatures, this entire synthesis is rather simple in that none of the chemicals or equipment is beyond the scope of the amateur chemist. I will try to present some more details in time. Until then, if anybody has any journal references or outright reprints they would like to present on this subject, please do so.

If I may ask....where did you get the Journal of Propellants, Explosives, and Pyrotechnics??
(Subscriptions are supposed to be extremely expensive!)

Whats the power of this stuff?

"Except for the cold temperatures, this entire synthesis is rather simple in that none of the chemicals or equipment is beyond the scope of the amateur chemist."

What about the tetranitrocubane? That isn't too common...

You must keep in mind that Mega's idea of what is an amatuer, and the rest of the worlds idea of what that means, are probably order of magnitudes apart.

:D

And whatever happened to the solid nitrogen explosive, ESN (Extended Solid Nitrogen)? Any updates?

Yeah Mega was probably talking about that bunch of amateurs at LLNL, or the kewls at Sandia, with all their primative equipment... <img border="0" title="" alt="[Wink]" src="wink.gif" />

I think N4, N8 and graphite-like nitrogen compounds are all still theoretical. I wouldn't be surprised if they were made in MINUTE quantities by condensation of atomic nitrogen though.

Mega, do you mean N2O5( and not N2O2)?The former is a powerful nitrating agent,but must be prepared right during the processing by reacting N2O4 with O3 and then condensed in dry ice to solidfy it before added to the reaction vessel.

"What about the tetranitrocubane? That isn't too common..".

Nitrating cubanes to the tetranitro level is not that hard,as long as you employ the right reactants.
Check this from USpatent#5998661

"Preparation of Nitrocubanes"

Potassium monopersulfate (4.0 g), water (50 ml), and acetonitrile, (15 ml), were mixed together to form a solution. Then, ozone was added until the solution was saturated. A second solution of 1,3,5,7-tetra-aminocubane hydrochloride in water, 200 mg in 15 ml, was slowly added to the first solution while ozone was slowly bubbled through the first solution. The reaction temperature was 0 degrees C. The addition of ozone was stopped after 2 hours; the reaction mixture was stirred overnight and 10 ml of acetone were added.

The reaction product was filtered and the filtrate was concentrated on a rotary evaporator. The concentrate was extracted twice with ethyl acetate (2.times.50 ml) and washed with aqueous HCl and then with brine. H NMR identified a tetranitrocubane product

Oh ,by the way,Mega,Before there was a site for this particular paper;
Journal of propellant,explosives and pyrotechnics
( <a href="http://jopeap.0catch.com/)" target="_blank">http://jopeap.0catch.com/)</a> but it was removed.
Is there any chance that it can be reactivated like your megalomania controversial chem labs ?

<small>[ March 30, 2002, 02:53 AM: Message edited by: cutefix ]</small>

Oh dear, I did mean N2O5, as a matter of fact I double checked that and made sure I put in the correct number for oxygen, but then I copied and pasted the sub formatting tags, so I must have undid my careful checking. How careless of me :o I consider the synth of tetranitrocubane to be obtainable, I will of course get that info as it is a powerful explosive in its own right.
Exact figures of the explosive velocity of HpNC are not yet available, or they have not been published anyway. With its density and structure the way it is, theory indicates HpNC should get up to around 9900 m/s vs CL-20's 9200 m/s, and HMX's 9100 m/s. Yes that would make HpNC 'the most powerful explosive' in the general sense.

I will be bringing back, err I mean Joe Pap will be bringing back, the online version of the Journal of Propellants, Explosives, and Pyrotechnics.
Joe would be more than happy if anybody happened to have saved any of those html documents, not the pdf's mind (those are fine), but the web pages themselves. It seems the only copies were lost, and the site would return a lot quicker if somebody could send them. Thanks in advance.

Mega, are you posting the entire procedure for HpNC (and TNC/other precursors) on your site? Folks, i forgot the Detonation Velocity of HNIW, but i thought it was higher than HMX for some reason...

HNIW is CL-20, which I have listed as 100 m/s faster than HMX.
I will be adding a synthesis for both TNC and HpNC to my website, but I will more than likely post the data here in raw form for commentary and accuracy checking before I make a formal webpage on my site.

i thought hniw had a vdet of up to slightly in excess of 10,000m/sec

The Vdet of HNIW is listed in the explosives archive (note link above) to be 10300 m/s. Is there new info that has lowered HNIW's power? I have seen this number in other sources and it became my figure. But a full 1200 m/s over HMX is asking for 13% more velocity and requires 28% more energy density, given the similar ratio of det. products from the two explosives. Does HNIW have to lose its 10 kps crown?

I think its better to look at these concise data for HNIW located in the USPatent #5,693,794 for reliable reference.The VDET and Detonation pressure agrees even with calculated values .

SUMMARY OF PROPERTIES

Appearance: alpha-modification, colorless rhombic prisms beta-modification, colorless needles or chunky prisms

Molecular formula: C.sub.6 H.sub.6 N.sub.12 O.sub.12

Molecular weight: 438.2

Oxygen balance (CO.sub.2 and H.sub.2 O): -11.0%

Nitrogen percentage: 38.36

Detonation velocity (calculated): 9.38 mm/micro-second (i.e, 9380 metres per second)

Detonation pressure (calculated): 428 Kbar

Heat of formation (observed): +228 cal/g

Melting point: 260.degree. C. (decomposition with phase changes to gamma-modification at 185.degree. C. and to delta-modification at 230.degree. C.)

Density (observed): alpha-modification 1.97 g/cm.sup.3 beta-modification 1.98 g/cm.sup.3

Impact sensitivity (H.sub.50) using 2.5 kg type 12 tool: 17-21 cm (alpha or beta-modification)

Friction sensitivity: 50% point: 902 lb (beta-modification)

Electrostatic sensitivity: 10/10 no fires (0.25 Joule) (alpha-modification)

The compound, 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW), may be utilized as an explosive in the same manner that other solid, crystalline explosive materials are used. The energy of the compound is superior to that of HMX, which has a detonation velocity of 9.1 mm/microsecond and a detonation pressure of 390 Kbar. The density of the compound is also greater than that of HMX (1.90 g/cm.sup.3). The compound is very stable to heat. It does not react readily with protic solvents such as water, unlike Sorguyl (tetranitroglycoluril) or hexanitrobenzene. On the other hand, the compound may be recrystallized from boiling water or boiling nitric acid. Additionally, the compound may be used as an oxidizer in solid fuel propellants.

The problem with these "new" nitrocarbons is that they have several crystal modifications which have different densities and different VoD's. Until now, chemists do not know how to isolate one particular modification. This is quite logical, as very small factors (type of lab glass used, precursors) can already affect which modification will crystalize out.

I have made 3D rotating molecules of <a href="http://student.luc.ac.be/~0219770/QUIZ.AVI" target="_blank">HNIW</a> and <a href="http://student.luc.ac.be/~0219770/ONC2.AVI" target="_blank">octanitrocubane</a>

<small>[ March 07, 2003, 06:15 PM: Message edited by: vulture ]</small>

In the recent patents for using HNIW in military application,USpatent
6,214,137 they are using the epsilon polymorph which has a higher density which equates to higher VOD.
It means that the workers have succeded practically in isolating the most useful isomer as done by Thiokol.
Until this time the main concern of the product developers is the refinement of the hexanitroisowurtzitane synthesis in order to bring down the manufacturing cost.