[HN Gopher] Preparation of a neutral nitrogen allotrope hexanitr...
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Preparation of a neutral nitrogen allotrope hexanitrogen C2h-N6
Author : bilsbie
Score : 34 points
Date : 2025-06-16 00:36 UTC (2 days ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| gus_massa wrote:
| Note that "C2h" is the symmetry[1] and "N6" is the chemical
| formula. Yes, 6 Nitrogen in a line, N-N-N-N-N-N with some weird
| bounds and internal charges, probably a good candidate to "Things
| I Won't Work With" in https://www.science.org/blogs/pipeline From
| the article:
|
| > _Detonation calculation details_
|
| [1] See for example another molecule with a different shape but
| the same symmetry in https://www.cup.uni-
| muenchen.de/ch/compchem/geom/sym_C2h.htm...
| bilsbie wrote:
| Isn't it a ring shape?
| gus_massa wrote:
| No, it's almost linear with a small glitch in the center
| https://www.nature.com/articles/s41586-025-09032-9/figures/4
| meepmorp wrote:
| That's just 3 nitrogen molecules in a trench coat
| rini17 wrote:
| No, they only mentioned that hexanitrobenzene has too small
| dissociation energy computed, sadly.
| rich_sasha wrote:
| > [Nitrogen compounds] are considered promising clean energy-
| storage materials owing to their immense energy content that is
| much higher than hydrogen, ammonia or hydrazine, which are in
| common use, and because they release only harmless nitrogen on
| decomposition.
|
| What the abstract mentions only sideways is that a key use of
| these properties is production of explosives - nitroglycerin,
| trinitrotoluene (TNT) or nitrocellulose (modern gunpowder) come
| to mind, and indeed, they store a lot of energy. Note all have
| "nitro" in the name.
|
| At this point I'm not sure you care that only exhaust gas is
| nitrogen.
| a3w wrote:
| Hexanitrogen? Nice, but Octanitrocubane is what GURPS promised
| for TL9.
|
| Found in the warhead table, yes: this is "cleaner" explosives,
| but military is not spending billions to safe the environment.
| But get a higher TNT-equivalent per kilogram.
| rbanffy wrote:
| How many nitrogens do we need to have a chemical primary for
| a fusion weapon?
| bell-cot wrote:
| I suspect you'd need about 0.013 M total, based on
| https://en.wikipedia.org/wiki/Brown_dwarf#Deuterium_fusion
| rbanffy wrote:
| Looks like a very tiny lump of metallic nitrogen.
|
| Eventually someone will make this.
| AstralStorm wrote:
| Definitely not, the primer also needs to be somewhat
| stable.
|
| This is one reason that even azides are not used in this
| capacity anymore, and metallic nitrogen would be orders
| of magnitude less stable. Not to mention requiring
| special conditions to not explode, like a laser trap or
| extreme pressures.
| rbanffy wrote:
| Whatever the conditions, if attained, would lead to a
| virtually undetectable fusion bomb. Nukes for everyone,
| yay!
|
| A visible amount of the thing wouldn't even need the
| fission part.
| WJW wrote:
| While it's true that most explosives use nitrogen-based
| compounds, only a vanishingly small amount of all nitrogen
| based compounds are used for military applications. Rough
| estimates are that about 85% goes to producing fertilizer, most
| of the rest is for various industrial applications and as a
| fuel.
|
| Relative to the scale of how much fertilizer humanity uses,
| there's just not all that much demand for explosives.
| perihelions wrote:
| - _" decomposition of N6 into three N2 is exothermic (DH0) by
| 185.2 kcal mol-1"_
|
| That's an impressive amount of energy, 9.2e6 J/kg--on the same
| order as carbon combustion. Wonder if it's a potential rocket
| fuel additive (it probably isn't, but fun to ask). By comparison,
| O3 is "only" 3.0e6 J/kg above diatomic oxygen.
|
| > _" is unlikely to decompose through [quantum mechanical
| tunneling], with an estimated half-life of N6 of more than 132
| years at 77 K (Supplementary Table 4). At 298 K, the computed
| half-life still amounts to 35.7 ms"_
|
| Better hope that fridge doesn't fail.
| WJW wrote:
| I guess you could have it as some sort of monopropellant? Have
| some cryogenically cooled N6 flow to the combustion chamber,
| where it heats up and self-decomposes. Initially you'd have to
| have some other form of thermal energy input to start the
| process but once it's going the heat coming off the reaction
| will trigger further reactions. One downside would be that
| you'd have much more trouble cooling the engine. Normal engines
| use the cold fuel and oxidizer flowing around the bell and the
| combustion chamber to cool them down, but with N6 heating it up
| before it hits the reaction chamber might be impractical. It
| would probably be a Bad Thing if it starts self-decomposing
| while still in the fuel lines...
| rbanffy wrote:
| You can store it inside the LH2 tank, but you'll need to use
| it completely before you run out of LH2 or it gets too hot.
| You might be able to inject it in a cold LH2 feed that
| doesn't pass by the cooling channels and injects directly
| into the combustion chamber so any N6 gets flushed into the
| chamber before the engine runs out of LH2. LH2+N6 needs to
| flow fast enough it doesn't heat up before it hits the
| chamber.
|
| Still, one commenter mentioned this is too explosive to be
| used as an explosive. That kind of warns me against thinking
| too much about this.
| xmcqdpt2 wrote:
| The best part is the Methods section, which opens with
|
| > Warning! Silver azide and halogen azides are extremely
| hazardous and explosive. Such compounds should be handled with
| utmost care and only in very small quantities (<5 mmol).
| Appropriate safety precautions (blast screens, face shields,
| Kevlar gloves, soundproof earmuffs and protective leather
| clothing) are necessary. Make sure to eliminate static
| electricity before handling. It is also crucial to avoid friction
| and light exposure and prevent any contact with metals during
| sample handling to ensure safety.
|
| That is, please do the synthesis in full armor, in the dark and
| don't touch anything more than strictly necessary.
|
| Also wear ear protection, because it's still going to go bang.
|
| I like the green energy twist in the intro too. "High-energy
| materials" is an euphemism chemists engaged in weapons research
| like to use. I went to some conference talks about high energy
| materials before, and research presented at those talks was
| always funded by various defence agencies. But maybe that's just
| a North American thing, this particular group only acknowledges
| funding from the innocuous Deutsche Forschungsgemeinschaft.
| greenavocado wrote:
| Can't help but to think of Azidoazide azide when I see azides
| mentioned
| HelloNurse wrote:
| > gas-phase reaction of chlorine or bromine with silver azide,
| followed by trapping in argon matrices at 10 K
|
| Certainly not a process that can be made simple, safe and
| efficient for use in a battery: explosives or rocket fuel are
| the only possible kinds of "clean energy-storage materials".
| _0ffh wrote:
| > Here we present the room-temperature preparation of molecular
| N6 (hexanitrogen) through the gas-phase reaction of chlorine or
| bromine with silver azide
|
| Hmmm, chlorine and bromine - off to a good start - then we come
| to silver azide.
|
| "Azide" immediately rings all my Derek Lowe bells, and yeah...
| it's exactly what you'd expect.
| wiredfool wrote:
| That would be this one: https://www.science.org/content/blog-
| post/things-i-won-t-wor...
|
| > We're talking high-nitrogen compounds here (a specialty of
| Klapotke's group), and the question is not whether such things
| are going to be explosive hazards. (That's been settled by
| their empirical formulas, which generally look like
| typographical errors). The question is whether you're going to
| be able to get a long enough look at the material before it
| realizes its dream of turning into an expanding cloud of hot
| nitrogen gas.
| myrmidon wrote:
| > Compounds consisting only of the element nitrogen [...] are
| considered promising clean energy-storage materials
|
| They are not actually serious about this, right?
|
| I feel if that directly acknowledging _Klapotke_ of all people is
| basically a thinly veiled concession that watever you synthesized
| is too explosive to even be used as an explosive. As seems to be
| the case here.
|
| Is there even a remotely possibility for this to be _used_ in any
| practical application?
|
| Noneteless, impressive paper, and getting that abstract into
| Nature is basically an achievement on its own already.
| AstralStorm wrote:
| I mean... You could use it in space instead of nukes as a
| propellant. Probably would be safer to make there too.
|
| Not useful otherwise yet unless there's some special synthesis
| requiring it that cannot be done in any other way.
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