You have got to be kidding me…

Hexanitrohexaazaisowurtzitane is a real compound? Who, what, wa… really?


Hexanitrohexaazaisowurtzitane /ˈhɛksɑːˈnaɪtroʊˈhɛksɑːˌæzɑːˌaɪsoʊˈvʊərtsɪteɪn/, also called HNIW and CL-20, is a nitroamine explosive with the formula C6H6N12O12. The structure of CL-20 was first proposed in 1979 by Dalian Institute of Chemical Physics. In 1980s, CL-20 was developed by the China Lake facility, primarily to be used in propellants. It has a better oxidizer-to-fuel ratio than conventional HMX or RDX. It releases 20% more energy than traditional HMX-based propellants, and is widely superior to conventional high-energy propellants and explosives.

Industrial production of CL-20 was achieved in China in 2011, and it was soon fielded in propellant of solid rockets. While most development of CL-20 has been fielded by the Thiokol Corporation, the US Navy (through ONR) has also been interested in CL-20 for use in rocket propellants, such as for missiles, as it has lower observability characteristics such as less visible smoke.

CL-20 has not yet been fielded in any production weapons system, but is undergoing testing for stability, production capabilities, and other weapons characteristics.

This stuff is just crazy. Two pentane rings (with nitrogen in them, so really azo something rings) and lots of oxidizer in the attached groups. Damn straight this will blow up. How in heck you make it is what would drive me around the bend.

Crazy ass explosive named Hexanitrohexaazaisowurtzitane

Crazy ass explosive named Hexanitrohexaazaisowurtzitane

First, benzylamine (1) is condensed with glyoxal (2) under acidic and dehydrating conditions to yield the first intermediate compound.(3). Four benzyl groups selectively undergo hydrogenolysis using palladium on carbon and hydrogen. The amino groups are then acetylated during the same step using acetic anhydride as the solvent. (4). Finally, compound 4 is reacted with nitronium tetrafluoroborate and nitrosonium tetrafluoroborate, resulting in HNIW.

Cocrystal product with HMX

In August 2012, Onas Bolton et al. published results showing that a cocrystal of 2 parts CL-20 and 1 part HMX had similar safety properties to HMX, but with a greater firing power closer to CL-20.

Cocrystal product with TNT

In August 2011, Adam Matzger and Onas Bolton published results showing that a cocrystal of CL-20 and TNT had twice the stability of CL-20—safe enough to transport, but when heated to 136 C the cocrystal may separate into liquid TNT and a crystal form of CL-20 with structural defects that is somewhat less stable than CL-20.

Oh. Sorry I asked…

OK, so it’s an improvement in solid rocket propellants (as long as it doesn’t blow up) and it can blow up nicely too. But really, would I want to be in the same county with something with that tight a ring with nitrogen in it, with two of them, with oxidizer on the vertices? Really?

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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24 Responses to Hexanitrohexaazaisowurtzitane

  1. tom0mason says:

    More info here http://ijetae.com/files/Volume2Issue4/IJETAE_0412_102.pdf
    The military like it, as the linked document says —

    CL-20 is no longer a laboratory curiosity. During
    the past few years, government and contractor laboratories
    (primarily Thiokol Corporation) have produced over
    10,000 pounds of CL-20 for energetic-materials research
    and development (R&D).


     Non-polluting
     Acid free
     Solid particulates free
     Lead free
     Transparent exhaust
     Increased performance
     Higher energy density

    High cost

    Only one disadvantage. Still it’s only government (tax-payer) money…

  2. Serioso says:

    There is an important distinction to be made between propellants and explosives. Much of what are called explosives are actually fast-burning propellants. Check out the wikipedia article on “Interior Ballistics” to understand the difference. More typically, what we call ‘explosives’ are shock sensitive: Combustion occurs everywhere at once, simultaneously, due to a shock wave, while more common propellants (like gunpowder) proceed by a rapidly growing heat wave. The distinction is important: You don’t want a gun or a canon to experience an explosive ignition. What is needed is a (fast) burn. As for this particular chemical, based on its structure and composition,I suspect it is an explosive, quite unsuited for use as rocket fuel.

  3. Larry Ledwick says:

    Some rocket fuels are explosive powders mixed with a dilute that prevents detonation. Most explosives will not propagate an explosion below a certain particle dimension or mass density.

    A true detonation propagates through the body of the material at supersonic speeds (faster than the local speed of sound as a supersonic shock wave drives through the material) were conflagration (ie gun powder propellants) burn on the surface of the material and their burn rate can be controlled by shaping/piercing the particles or coatings that delay ignition.

    Det Cord burns (very very fast) but it burns. Common nitrocellulose gun powders can detonate under the right conditions but under normal loading densities and particle sizes they burn on the surface.

    Below a characteristic size a given explosive does not generate enough energy as it decomposes to drive a true detonation. For example ANFO blasting mixtures cannot achieve maximum detonation velocity in bore holes smaller than about 9″ diameter and will not propagate an explosion in a bore hole smaller than its critical diameter of 1.25 inches. Detonation is unreliable below about 2″- 3″ diameter bore hole and may only detonate near the primer then extinguish.

    Fun little video includes a segment where you can actually see the rate at which det cord burns. (normally it is too fast to perceive)

    video with det cord segment

  4. philjourdan says:

     High cost

    Only one disadvantage. Still it’s only government (tax-payer) money…

    For an organization that pays over $200/gal for “green” fuel, how expensive can it be?

  5. Demetrius says:

    Is this the stuff in male deodorant sprays?

  6. Steven Fraser says:

    Looks like a space invader schematic.

  7. John F. Hultquist says:

    While taking a chemistry class (about 1963), a speaker came and demonstrated a number of interesting chemical reactions. He did things such as mixing chemicals together while singing a school’s song and where, say, the words were “red” and “black” – the mixture in the beaker would change from “clear” to red to black. Fun stuff.

    One thing he did – in a slightly modified stainless steel milk can – was to place wheat flour and a candle near the bottom of the enclosed space. With the candle lit, he would send a puff of air into the can and at the flour dust. The can’s top – not tightly fit – blew about 20 feet into the air.

    Here is a video of a TX Aggie doing much the same, but not near as spectacularly:


    Cost of the flour dust – not an issue.

  8. Jay Dee says:

    One of the funniest books on Chemistry is “Ignition!: An informal history of liquid rocket propellants” by John D Clark. Treeware copies are verging on the ridiculous but PDF versions are available.

  9. cdquarles says:

    @ John, yep. Cotton dust or saw dust work just as well, especially if you can get a nearly uniform size that’s small enough. A textile mill that I know of had a major explosion from a spark and cotton dust.

    An explosion is simply a very rapid expansion of gas (on the order of 300 m/sec or more. You don’t necessarily need a chemical reaction to do this (a propellant and an accelerant).

  10. rocketplumber says:

    No discussion of screwball chemicals is complete without Derek Lowe’s take on it. In his “In the Pipeline” column he has a recurring feature:


    “But now comes the unexpected habanero. Hexanitro? Say what? I’d call for all the chemists who’ve ever worked with a hexanitro compound to raise their hands, but that might be assuming too much about the limb-to-chemist ratio.”

  11. E.M.Smith says:


    Now THAT was a fun read… good comments too.

  12. E.M.Smith says:

    @John F. & CD:

    A trick picked up long ago from somewhere…

    Say you need to take down a small house used by bad guys, but only have a few ounces of explosive. Not enough to do the place. What to do? In the cupboard is a sack of flour…

    Place tuna can sized can packed with C-4 in the center of the floor. Place 5 lb sack of flour on can. Leave the area. Detonate. The c4 blows the flour as fine fast hot dust into the whole space mixed with air oxidzer. A dramatic dust explosion follows. Building all gone…

  13. Paul Hanlon says:

    I remember when I would be cleaning out my father’s factory. Back then we used to burn all the sawdust in a barrel, but if you pack too much it would just smoulder for days. And as 12 year old boys with a lot of curiousity are wont to do, I tried to hurry up the process by firing the sawdust in the air, and watching the flame-burst. And it worked for a while until the wind changed, and I ended up singing my eyebrows and fringe.

    Just watched a very interesting video of a CNN interview with Roger Stone back in 2000 (when CNN actually reported news), when Donald Trump was considering running for the Reform Party, and Stone was on the campaign team.

    Surprising the amount of similarities between what he was running on then, and the things he said, and what happened this time. Also, the difference in discourse, where he was allowed to speak his piece. So different from what we have now.

  14. J says:

    Yes, that molecule has WAY too many nitrogens.
    And the strain energy of those rings ! The energy pay-off is sooooo big when all those nitrogens rearrange and form stable N2 molecules.

    That things I won’t work with blog used to be great, I thing it is extinct now.

  15. D. J. Hawkins says:

    Ammonium perchlorate is a standard ingredient in rocket propellants. It is also more shock sensitive than nitroglycerin (4 cm vs 18 cm). I couldn’t find the info on hexanitrohexaaza, but it’s clear that there is quite a bit of crossover between propellant and explosive. Often it’s only a matter of confinement.

  16. Larry Ledwick says:

    This is an example of the transition from rocket fuel oxidizer to explosive.
    Ammonium Perchlorate factory explosion video

  17. E.M.Smith says:

    There are clear propellants ( like CO2 driving water out a nozzle) and there are clear explosives (like nuclear bombs).

    IMHO, everything in the middle is a matter of context… I say this as I am partially deaf due to a “safe propellant” transitioning to “shock wave detonation” despite the particular material being described as one of THE most difficult to get to detonate and requiring a strong blasting cap to set it off (and that usually with a booster charge of something else).

    So, unfortunately, I’m way too familiar with the transition (and, of course, added more to that understanding after the fact).

    IF it is a chemical compound, division between propellant and explosive really relies a LOT more on confinement, circumstances, and contamination (that often arises from chemical reaction with surroundings after manufacture) than any inherent property of the material.

    Any one doubting that is invited to follow my directions on how to convert a propellant that can not be detonated with a rifle shot or even a weak blasting cap into a substance that detonates on stirring with a plastic spoon. I’ll be in the next building over while you do the mixing…

  18. D. J. Hawkins says:

    EM, you’ve piqued my curiosity. I have a copy of The Chemistry of Powder and Explosives by Davis. Where should I look for the phenomenon you mention?

  19. E.M.Smith says:

    We were informed, during our interrogation in the hospital, that the information had been removed from the university library as it was thought it too much of a risk to be known. Needless to say, we were rather pissed that, having actually DONE all the book work to “know the subject”, we were in fact damaged at least in part by the hiding of it. (The “lead” was a dual Physics / Chemistry major and A+ student, BTW.)

    However, knowing that it would be used for Bad Things, and that it turns some relatively available and safe materials into shock sensitive materials, I’d rather not divulge to a public forum what all it is. Let’s just say it involves phosphorus and the relationship to nitrogen…

  20. Larry Ledwick says:

    D.J. when you take hazardous materials training they teach to cops and fire fighters you get exposed to several incidents where normally mostly benign things become not so benign under the right conditions, resulting in emergency responses due to unexpected chemical reactions.

    As EM mentions it is information that is not widely discussed just because some of them have been misused. (rule of thump – the things chemistry books tell you to avoid)

    Common materials you can buy in most any large store that do not play well with each other in a go bang or make flame sort of way.

    In the 1960’s one of those combinations was used by rioters to set fire to police cars by making a very simple incendiary mixture that would spontaneously burst into flame after about 30 seconds in a hot car producing a short lived but very hot flame which quickly set the back seat on fire.

    I also tinkered with some of those chemical oddities when I was young and stupid and got some surprises because I didn’t know all the details (and learned some interesting things), but it is very dangerous due to the instability and self heating behavior of some of them are very unpredictable.

    While trying to come up with a “safe” example for hazardous materials demonstrations like the candle and flour demonstration of dust explosions, I had a plastic bag of a mixture simply burst into flames while sitting unmolested on a (luckily) non-combustible surface. After a little follow up investigation I discovered the key conditions were very subtle and hard to avoid. In that case, the mixture was (relatively) safe while “completely” dry, but even a trace of moisture in the ziplock bag would lead to spontaneous combustion with unpredictable time delay.

    An interesting statistic is about 1/3 of the bomb builders that built crude bombs in Cuban and Latin American countries in the 1960s blew themselves up because the mixtures they were using were very unforgiving of errors.

  21. D. J. Hawkins says:

    I spent 5 years of my life as a front line supervisor in a nitroglycerin manufacturing operation and then designed ultra-high purity piping systems for silane, among other interesting gases. I am somewhat familiar with things that go boom or start burning and don’t want to stop.

  22. Larry Ledwick says:

    Yeah that would qualify ;)
    (follow the bread crumbs)
    It took me a couple years to figure out exactly what those arsonists were using in the 1960’s to set fire to police cars, but a lot of digging in chemistry references for things you should not mix, and hazardous materials incident reports eventually led me to the answer. The Hazmat instructors and bomb techs I worked with would talk about it in general but always left out key bits (not sure even they really knew the full story – just repeated an “urban legend” sort of description). They referred to one brand name product by name, which I eventually figured out contained a commonly used chemical in its formulation (used by many other over the counter products by the way and it was perfectly safe in its retail use – it was a hair cream product). It was important to understand what they were doing because of my job as an emergency planner, as we were writing hazardous materials response plans at the time and we needed to factor in chance mixtures of common materials which would lead to problems.

    Once I figured that out, I knew the actual active chemicals and the reaction involved and eventually chased it to its root ingredients. You can buy both key ingredients over the counter at stores like Walmart. The chemical reaction actually can be triggered by 3 different chemicals that I know of mixed with a 4th but their level of reactivity varies. I am sure what EM has mentioned is the same sort of chance mixture that does not play well with others.

  23. E.M.Smith says:


    Unlikely to happen by chance in most places as the fertilizer rarely gets near the “other stuff”. But easy to do with normal lab chemical supply or many industrial metal working suppliers.

    Basically, anyone with an industrial chemical / manufacturing operation can innocently buy the needed things.

    I did some web searches and did not see the exact “mix”, but did see a LOT that was already published. So, for D.J.: Search on “explosive sensitizer” and look at some of the patents et. al.

    That is likely more “hint” than ought to be in print, but since it seems the info is mostly out there with the right search terms, I think I’m not adding any new risk. Just keep your fingers and toes…

    It looks like there is an active industry based on finding ways to exploit sensitizers in explosives. Interesting to note it is largely so you can ship and handle insensitive things ( i.e. safety) and only make it into “boom stuff” of hazard in the next to last step. One interesting patent I found was for a blasting cap (one of THE most dangerous bits as it is a primary explosive) with a ‘break me’ ampule inside. The liquid sensitizes the absorbent solid and you have a blasting cap. Useful for military teams where you carry them in your boot while jumping out of airplanes and being shot at. So nicer way to keep them toes…

    In General:

    It is important to note that stable and safe energetic compounds can make the transition to propellant and even on to explosive (sonic or supersonic detonation wave causing molecular ‘reassembly’…) based only on: environmental conditions, contaminants, temperature, pressure, humidity, and a large number of “sensitizers” only a few of which are commonly known.

    Anyone thinking they KNOW a propellant or an explosive is absolutely safe will be called “lefty” or “gimpy”… eventually…

  24. Larry Ledwick says:

    Yes sensitizers area a big issue in hazmat incidents. A good example look at the detail reports about the Texas City disaster where two ships loaded with ammonium nitrate blew up.


    What they don’t even mention in this wiki discussion is galvanized metal (zinc) in the ships hold likely contributed to the reaction. zinc is a sensitizer for ammonium nitrate and the two react with an exothermic reaction.

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