[HN Gopher] Pentaborane(9)
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Pentaborane(9)
Author : rbanffy
Score : 37 points
Date : 2024-04-06 11:28 UTC (2 days ago)
(HTM) web link (en.wikipedia.org)
(TXT) w3m dump (en.wikipedia.org)
| pureheartlover wrote:
| We often see green flames shooting across the sky without
| descending in SA near the Woomera test facility. I put it down to
| boronated fuel, but most people put it down to meteors with high
| nickel iron or copper content.
| oger wrote:
| Naah - she'll be right mate ;-)
| keepamovin wrote:
| _As one of the compounds that have a NFPA 704 (fire diamond)
| rating of 4 for every category, it is naturally extremely
| dangerous. Above 30 degC it can form explosive concentration of
| vapors with air. Its vapors are heavier than air. It is
| pyrophoric--can ignite spontaneously in contact with air, when
| even slightly impure. It can also readily form shock sensitive
| explosive compounds, and reacts violently with some fire
| suppressants, notably with halocarbons and water. It is highly
| toxic and symptoms of lower-level exposure may occur with up to
| 48 hours delay. Its acute toxicity is comparable to some nerve
| agents._
|
| Friendly
| carterschonwald wrote:
| Fluorine gas seems safer by comparison
| keepamovin wrote:
| Friendly fluorine and its positively sociable cousin
| hydrofluoric acid, the lifes of the party compared to
| pentaborane.
|
| It's like it's _asking_ to be banned.
| perihelions wrote:
| ?Porque no los dos?
|
| https://en.wikipedia.org/wiki/Liquid_rocket_propellant#Bipro.
| ..
|
| edit: I found people that tested the pentaborane/fluorine
| combination specifically,
|
| https://apps.dtic.mil/sti/trecms/pdf/AD0270941.pdf ( _"
| EXPLORATORY RESEARCH ON HIGH ENERGY PROPELLANT SYSTEMS"_
| (1961))
|
| - _" An instantaneous hypergolic ignition occurred with a
| very long brilliant greenish-white flame and clouds of dense
| white smoke. Approximately four seconds after the start of
| the run, a leak developed in the fluorine valve stem. The
| lowered pressure in the fluorine line caused a flashback and
| the fluorine line ruptured. The very fuel rich combustion and
| decomposition of pentaborane which then resulted quickly
| plugged up the injector holes with the thick polymerized
| products of decomposition of pentaborane."_
| GuB-42 wrote:
| This made me think about the excellent "things I won't work with"
| series by Derek Lowe.
|
| https://www.science.org/topic/blog-category/things-i-wont-wo...
|
| He didn't write write an article about pentaborane, he left this
| one to Max Gergel https://www.science.org/content/blog-post/max-
| gergel-s-memoi...
| x1f604 wrote:
| From the book:
|
| (Warning: Spoilers ahead)
|
| > The next day I told Parry that I was flattered but would not
| make pentaborane. He was affable, showed no surprise, no
| disappointment, just produced a list of names, most of which
| had been crossed off; ours was close to the bottom. He crossed
| us off and drove off in his little auto leaving for Gittman's,
| or perhaps, another victim. Later I heard that he visited two
| more candidates who displayed equal lack of interest and the
| following Spring the Navy put up its own plant, which blew up
| with considerable loss of life. The story did not make the
| press.
| keepamovin wrote:
| Hahaha. Fuck. The history of pentaborane is littered with
| human tragedy. What an appropriate compound for this troubled
| age.
| lazide wrote:
| Definitely don't read about the history of acetylene then.
|
| Same as it's always been.
| araes wrote:
| Hexanitrohexaazaisowurtzitane is pretty funny and very similar.
|
| "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."
| (classic chemist joke)
|
| "make a more stable form of it, by mixing it with TNT. Yes,
| this is an example of something that _becomes less explosive_
| as a one-to-one cocrystal with TNT.. "
| gilleain wrote:
| Wacky structure! Not just a cage, but also has 2 B-H-B bonds
| (https://en.wikipedia.org/wiki/Three-center_two-electron_bond) -
| no wonder it is so reactive...
| keepamovin wrote:
| Yeah, amazing that something so relatively unstable can
| actually exist long enough to be dangerous. I suppose the
| exothermic output is not helped by how stable H2 is.
| amelius wrote:
| Do other molecules fit inside the cage?
| gilleain wrote:
| no, far too small i would think. not sure what the smallest
| cage is that can act as a host-guest complex
|
| https://en.wikipedia.org/wiki/Host%E2%80%93guest_chemistry
|
| A fun one is Prof Rebek et al's 'tennis ball' - bisglycoluril
| that forms two halves that cup around a guest:
|
| https://www.scripps.edu/newsandviews/e_20011203/rebek1.html
| ribs wrote:
| Hey, you're not giving pentaborane enough credit - it's got 4
| of those bridging hydrides.
| office_drone wrote:
| I recall this being mentioned in Ignition!: An Informal History
| of Liquid Rocket Propellants [0] :
|
| Boranes are unpleasant beasts. Diborane and pentaborane ignite
| spontaneously in the atmosphere, and the fires are remarkably
| difficult to extinguish. They react with water to form,
| eventually, hydrogen and boric acid, and the reaction is
| sometimes violent. Also, they not only are possessed of a
| peculiarly repulsive odor; they are extremely poisonous by just
| about any route. This collection of properties does not simplify
| the problem of handling them. They are also very expensive since
| their synthesis is neither easy nor simple. But they possess one
| property which attracted rocket people to them as hippies to a
| happening. They have an extremely high heat of combustion -- gram
| for gram about 50 percent more than jet fuel.
|
| [0] https://www.amazon.ca/Ignition-Informal-History-Liquid-
| Prope...
| NotYourLawyer wrote:
| >Fifteen years ago, people used to ask me "What _is_ an exotic
| fuel anyway?" and I would answer "It's expensive, it's got
| boron in it, and it probably doesn't work."
|
| What a great book.
| neglesaks wrote:
| Is it as much fun to work with as Azidoazidolazide?
| jonathrg wrote:
| I was confused because I read the 9 as a manpage section.
| perihelions wrote:
| 9 Kernel routines [Non standard]
| ale42 wrote:
| syscall(SYS_PENTABORANE, 0x42);
| perihelions wrote:
| Yup, that's non-standard alright.
| simne wrote:
| As I remember, Russians once even launched "Soyuz" (R-7) on
| Pentaborane, achieved some additional kilograms of load.
| Fortunately , all finished ok, but they don't repeat these
| experiment "because of expensive".
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(page generated 2024-04-08 23:01 UTC)