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Things I Won't Work With: Dioxygen Difluoride (2010) (science.org)
258 points by jmcgough 4 months ago | hide | past | favorite | 75 comments

My personal favorite article from Derek Lowe about a chemical that isn't actually all that dangerous... but you still likely don't want it around.


I think my favorite from the series is this one, about a high-nitrogen compound so wildly unstable that it detonated when the lab turned on the spectrometer:


There's a great video on producing and testing that substance: https://youtu.be/-Sz4d7RQB6Y

Interestingly, it's more stable than most online sources give it credit for

He doesn't address this, but some comments do: did he really get the pure molecule or was it some impure compound that made it less sensitive?

The large crystal size is a pretty sure bet it's pure. That recrystallization he showed was a thing of beauty.

There is a comment addressing this and mentioning that (as far as I understood) there could be excess hydrate that is part of the natural crystallization process. Also he could get the reaction wrong and it's large crystals of a different molecule.

I just find it hard to believe that a renown lab specialzing in highly explosive compounds had this stuff explode when turning on the spectrometer, but he could hit it with a hammer.

I don't assume malice on either part, so the best explanation for me is that they were testing different things.

Given that he did it using a different synthesis using public shop grade starting materials in his garage and having no equipment to really verify his intermidiates and final compound it also seems likely. Also this is not addressed in the video. The video is popular/humorous science and not research afterall.

I'm actually a bit baffled that this video is taken at face value as disproving the labs original publication. But I also can't put the 1.5 Joule part in relation and a spectrometer creates more force than a soft hit from a hammer?

He addresses the disproval part: he didn't disprove their paper. He stated that just because it's below their threshold for sensitively doesn't mean it's super ultra mega sensitive, it just means that it's highly sensitive. 1.5 Joules is more than you think: a hammer tap could easily be less than that (lift a 100g weight a 1.5 meters off the floor: that's 1.5J of potential energy), however, as he puts it, that's still "sensitive as dicks". As for it blowing up in the mass spectrometer, that can happen if it started to decompose over time, accidental friction, accidental x-ray activation, too much in one spot, etc. I'm sure if he worked with the substance more than once or twice it's possible he'd have a random detonation or two. The paper and this video easily exist cooperatively rather than adversarially, and I think he was more calling out the science popularizers which exaggerated claims about it. In fact, he does nothing but mention things from the paper as being accurate.

Thanks, that makes sense.

Selenophenol is also a good one: https://www.science.org/content/blog-post/things-i-won-t-wor...

> The biggest stinker I have run across... Imagine 6 skunks wrapped in rubber innertubes and the whole thing is set ablaze. That might approach the metaphysical stench of this material.

I've not had personal experience with selenophenol but I wonder how it compares with thioacetone when it comes a human's ability to detect it.

Here's a stinky selenium anecdote from when I was a kid. In those days I used to build electronic projects out of parts from war surplus equipment. This was before the time when silicon diode rectifiers were cheap enough to buy on a kid's pocket money (especially so the high current variety), so the fallback was either vacuum tubes or selenium rectifiers.

Anyway, selenium rectifiers were cheap and plentiful except that I didn't have easy access to the high current variety. This led to the rectifiers often being overloaded and sometimes failing catastrophically. It turns out that in their death throes selenium rectifiers emit the most horrible pungent stink somewhat akin to hydrogen sulphide, however once one becomes familiar with the stench there's no mistaking it for H2S.

I've been known to stink the house out much to my mother's chagrin. Yes, even back then I was aware that these selenium fumes were toxic so I did exercise some care but it'd not have passed any of today's occupational health standards.

BTW, selenium rectifiers can be remarkably tolerant of overload and abuse, moreover they warn you when overstressed or they're about to fail as they begin to stink to high heaven.

Goddammit now I really want some of this, just to see how bad it is.

Knowing how "good" glass stink bombs were back when I was in high school, I have zero interest in anything more potent.

Was pretty good when Mark Rober tested his new “Fart Spray” on Macaulay Caulkin (the kid from Home Alone). Video here at 1m50s in https://youtu.be/a_TSR_v07m0#t=110

I'm surprised something so potent was never used as a chemical weapon. Sounds like it could easily clear out a trench or riot in the streets.

In the text it is mentioned that the chemical requires significant effort to crack or activate for the desired (or undesired) effect. Of which I assume is difficult to carry out under combat conditions.

Similar compounds have been used as chemical weapons before but eventually give way to more modern agents.


It lacks some desirable properties as chemical warfare agent. For one, it doesn't disperse easily and is even noticable at low concentrations. Meaning if you fill at trench with this, it is likely your own trench will notice it too and you won't be able to enter the field for a bit. And everything in the field will stink too for a while, so you can't take advantage of some resources there.

Reminds me of the Neal Stephenson novel Zodiac, where a similar agent was used in an offensive manner.

If I had any inclination and cause for terrorist attacks...

Following a link in the comments gets you to the PDF of Streng's 1962 paper, with some good notes. Having a Pyrex cylinder of this stuff sitting in anything other than a cryostat 20 miles from civilization sounds like a very bad idea.


If I wanted to synthesize this stuff, I think my preferred method would be SCP-294


> SCP-294

I'm curious as to what a "safe distance" is when requesting a cup of anti-water. Reacting 8 ounces of antimatter with a similar amount of matter releases energy on the order of a large thermonuclear bomb.

Well, obviously SCP-294 agrees it's a terrible idea. Possible invocation of self-preservation logic.

A lot of it comes out as neutrinos though.

Does it? I thought it was pretty much pure gamma radiation.

Low energy electron-positron annihilations produces photons. Higher energy annihilation produces all sorts of stuff: https://en.wikipedia.org/wiki/Annihilation

“ No, elemental fluorine has commanded respect since well before anyone managed to isolate it, a process that took a good fifty years to work out in the 1800s. (The list of people who were blown up or poisoned while trying to do so is impressive).”

The link intrigued me to click but unfortunately it 404ed. That led me to hunt down the list, and I found this snippet on an Royal Society of Chemistry page [0]:

“Sir Humphry Davy, Louis-Joseph Gay Lussac and Louis-Jacques Thenard all suffered intensely from the effects of inhaling hydrogen fluoride. Davy suffered injury to his eyes and fingernails. George Knox and his brother, Thomas Knox, both suffered from hydrofluoric acid poisoning. Thomas Knox nearly died. Paul Louyet and Jerome Nickles died during their investigations, presumably due to the effects of inhaling HF.”

[0]: https://edu.rsc.org/feature/the-discovery-of-fluorine/202024...

A fictional short story by Charles Stross that is a fitting companion piece to this article. An amusing discussion about using extremely dangerous substances as rocket fuel.


The "John D. Clark" in that story is the author of "Ignition!: An informal history of liquid rocket propellants", available from https://archive.org/details/ignition_201612 and frequently posted on HN (see https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... ).

That book describes a number of approaches with beryllium: https://archive.org/details/ignition_201612/page/n201/mode/2...

> Recently they have been experimenting with beryllium instead of aluminum. Combustion efficiency with these propellants, particularly the beryllium-based ones, is bound to be bad, since the chamber temperature is comparatively low. ... About all it proves is the willingness of rocket people to try anything, no matter how implausible, if they can con NASA or one of the services into paying for it. ...

> When the combustion difficulties are added to the toxicity of BeO and the price of beryllium, there isn’t really much point in continuing with it.

and with fluorine, in the liquid form: https://archive.org/details/ignition_201612/page/n39/mode/2u...

> The optimum oxidizer is liquid oxygen. (“Fluorine might be good, but its density is too low, and it’s a holy terror to handle.”)

and in an oxidizer that can decompose: https://archive.org/details/ignition_201612/page/n87/mode/2u...

> O2F2 [FOOF] had been reported but was unstable at room temperature ... [a list of other compounds, concluding] ... So ClF3 it had to be. ... It is also quite probably the most vigorous fluorinating agent in existence-much more vigorous than fluorine itself. Gaseous fluorine, of course, is much more dilute than the liquid ClF3, and liquid fluorine is so cold that its activity is very much reduced.

The next page (p74) describes an industrial accident with it, then its use in aerospace:

> The results were excellent, but the difficulties were infuriating. Ignition was beautiful —so smooth that it was like turning on a hose. Performance was high—very close to theoretical. And the reaction was so fast that you could burn it in a surprisingly small chamber. But. If your hardware was dirty, and there was a smear of oil or grease somewhere inside a feed line, said feed line would ignite and cleverly reduce itself to ashes. Gaskets and O-rings generally had to be of metal; no organic material could be restrained from ignition. Teflon would stand up under static conditions, but if the CTF flowed over it with any speed at all, it would erode away like so much sugar in hot water, even if it didn’t ignite. So joints had to be welded whenever possible, and the welds had to be good ...

and that's before getting to the "real difficulties."

Stross certainly read "Ignition!" before writing that short story - https://www.antipope.org/charlie/blog-static/2009/10/there_i... .

Here's most last HN discussions about most of the articles in the "Things I won't work with" series. Note that the content was published at least on three different domains in the last years (science.org, sciencemag.org, corante.com):


It reminds me of a similarly toned book called “Ignition!” By John Clark that is about the history of the development of rocket propellants. Recommend for a fun read.

I am reading it at the moment. I like the writing style and it is an interesting subject, but I am bit hampered by my lack of knowledge about chemistry.

It's really, really good. Short but well-written.

The one on chlorine trifluoride (linked in OP, but fixed link) is also really good: https://www.science.org/content/blog-post/sand-won-t-save-yo...

“It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively.”

Fantastic! I can see where Derek Lowe got his writing style inspiration.

Today, he writes about the world of medicines. His Twitter feed is excellent if you want to know more about some of the finer details about COVID related medicines: https://twitter.com/dereklowe?s=21.

I 2nd this - never heard of this before and I loved the 3 mins it took to read.

>coping with a metal-fluorine fire

Good lord

Glad it was reposted a ninth time. I had never seen it, and it led me down an immensely interesting rabbit hole.

If you like this style of writing, I have a treat for you: https://library.sciencemadness.org/library/books/ignition.pd... (if you haven't already read it. Fascinating stuff.)

Ah you are one of todays lucky 10000.


I don’t know how many times I’ve read this article before, all I know is that today is the day I’ll read it again.

Recipes about Satan’s Kimchi are irresistible.

My dad used to be a chemical engineer and one evening his "what did you do at work today?" story started with a chucle: "So one of the lab guys was doing this thing where you boil concentrated hydrochloric acid in a glass reactor and add cynanide.....".

Suffice to say it ended up on the evening news because a residential area had to be evacuated.

Reminds me of this classic (also In the Pipeline): https://www.science.org/content/blog-post/sand-won-t-save-yo...

Oh, then you will love DimethylMercury https://youtu.be/h049Hgfk-BI

Curiously, the MSDS indicates SilverShield gloves but does not specifically call out latex gloves as permeable and counter-indicated. This seems like a disastrous error of omission.


> Skin: Causes skin irritation. May be fatal if absorbed through the skin.

I’m sure the actual users read these things thoroughly, and the second point is called out above, but that ___really___ buries the lede.

I read somewhere that in professional dealings with toxic and caustic substances no latex glove would ever be considered impermeable but immediately replaced upon contact with a new pair. The trick is to systematically avoid anything splashing by applying best practices.

Karen Wetterhahn did replace her (latex) gloves immediately after spilling a drop of dimethylmercury on them, but it killed her anyway.

My chemistry teacher warned me to stay away from people who would use the ° sign for Kelvin ("90°K") or leave it out when talking about degrees centigrade ("-180C")... this guy does both


It is true that one should say just Kelvin and not “degrees Kelvin”.

But it wasn’t always so. From https://en.wikipedia.org/wiki/Kelvin

> In 1967/1968, Resolution 3 of the 13th CGPM renamed the unit increment of thermodynamic temperature "kelvin", symbol K, replacing "degree Kelvin", symbol °K.

And from Lord Kelvin himself in his "On an Absolute Thermometric Scale", a copy of which is at https://web.archive.org/web/20080201095927/http://zapatopi.n...

> The characteristic property of the scale which I now propose is, that all degrees have the same value; that is, that a unit of heat descending from a body A at the temperature T° of this scale, to a body B at the temperature (T-1)°, would give out the same mechanical effect, whatever be the number T. This may justly be termed an absolute scale, since its characteristic is quite independent of the physical properties of any specific substance.

So even Lord Kelvin himself was originally speaking of degrees in his absolute scale.

>> In 1967/1968, Resolution 3 of the 13th CGPM renamed the unit increment of thermodynamic temperature "kelvin", symbol K, replacing "degree Kelvin", symbol °K.

Which is particularly relevant given the usage is within a quote of a 1962 paper

He doesn't, he consistently omits the degree symbol. It's used in a direct quote

By the way, there is such a thing as Tetraoxygen difluoride, if FOOF isn't insane enough for you.


Took me a minute but finally found a link for the category:


FOOF, the compound that makes things go "foof".

Are there any other onomatopoeic chemicals out there?

Not an onomatopoeia but Sodium Citrate, which is used to create cheese that melts Into a smooth consistency, is na3c6h5o7 or NaCHO.

That would be NaOC(CO2H)(CH2CO2H)2, though, not NaCHO. NaCHO2 is sodium formate. NaCHO would involve deprotonating formaldehyde to get a CHO- ion you could make a sodium salt of. This might be possible, but definitely not in water.

Wikipedia has a list of funny chemical names, here: https://en.wikipedia.org/wiki/List_of_chemical_compounds_wit...

My favorite is probably Arsole, which has an apt diagram: https://upload.wikimedia.org/wikipedia/commons/4/47/Arsole.p...

Oh wow. That’s goatse spectrum too.

When it comes to the potency of the odor of thioacetone, it seems to me there are two issues of interest: detection and dilution.

1. The first question is how detectable is thioacetone to the human nose, that is how many molecules are actually needed before someone can actually detect it? The second is, is thioacetone the most detectable molecule known to us, if not then what is it?

It seems to me these are important questions for various reasons. Determining the absolute sensitivity or limiting resolution of our sense of smell could be tied up with out ability to detect† thioacetone. Then there's the question of how our sense of smell compares with other animals, dogs for instance. Dogs are renown for their acute sense of smell and we know they have many more smell receptors hence the acuity of their sense compared with humans. My question is do dogs' receptors have the same level of resolution (molecules versus detection) as do humans and does that change from molecule to molecule? Experts please let us know.

If these facts are still not well understood then perhaps thioacetone may be a good research tool for the purpose.

† Incidentally, it seems to me we've a similar issue with our ability to taste stuff, for instance, the chemical denatonium (Bitrex) is the most bitter substance known to humans and humans can detect it in extremely small amounts. However, the extreme sensitivity of humans to the chemical doesn't necessarily apply to other animals, rats for instance, which makes it a good denaturant for rat poisons, etc.

2. The matter of dilution. It seems to me that our experience of dilution is a bit like exponentiation in that our human sense of scale doesn't work very well when things change at exponential rates. Exponentiation often catches up with us because its effects/actions are 'outside' our normal daily (human) experience. Well, I reckon dilution is a bit like that (certainly so at the edges).

We often wash stuff away until there's seemingly nothing left of it and we think it's gone but as chemists know this is often far from being the case. I learned this the hard way as a kid when doing photography after I'd failed to leave my prints in running water sufficient time to wash away all the hypo (if I recall the recommended washing time was 5 minutes and I only washed for about a third that time). The prints looked perfectly OK for some hours afterwards but by the next day, they'd gone a horrible brown color. A lesson learned: insufficient removal of unwanted chemical can be problematic even when there's seemingly precious little or no obvious trace of it left. The fact is it's often very difficult to dilute stuff to the point where its effect is truly negligible.

It seems to me that in daily life we've very little idea of (and pay very little attention to) the amount of unwanted stuff that remains after we, say, have washed something clean. In practice we've very little idea of how much of residual chemical remains in a container after it's been washed and cleaned and is eventually transferred to a new and different solution when the container is reused. Getting a feel for cleanliness, purity and impurity of substances, residues etc. is a lot harder than it seems for we fail to consider the fact that there are a great deal more molecules involved in processes than we can actually comprehend (or are cognizant of in the mental sense). That is, if something is diluted well past the point where we can see or smell it then we've a tendency to assume that very little or nothing of consequence remains whether it's in fact true or not.

It seems to me that thioacetone is almost the quintessential chemical to demonstrate dilution, impurity, presence of residual molecules etc. by virtue of the fact that it's so easily detectable in only trace amounts. The fact that it isn't dangerous at levels long past where humans can detect it—and given how bad it actually smells would make it useful (and very memorable) for such training exercises.

No doubt strict protocols would apply to the conducting of such lessons.

These things are so reactive they can't exist outside specific conditions in the lab.

Man that's some bad writing. Just get to the point and stop trying to be funny.

I love the ending of that article :)

> "blown up or poisoned"

link is 404 =(

This sounds very nearly almost as toxic as dihydrogen monoxide- a truly deadly substance[0] that must be used very carefully.


[Edit] tough crowd tonight.

I appreciate the attempt at humor. Try to make a less polarizing joke next time.

This will always be funny.

Keep living the dream.

There are countless people out there who know nothing of chemistry and this is a great way to make a point, or make them laugh dependent on the framing.

http://dhmo.org/ has always been my go to URL.

Funny joke if you're 12. Which I guess is why everyone heard it from their middle-school chemistry teacher.

When I was a snot-nosed kid I tried that joke on a chemist family friend. He helpfully informed me that hydrogen hydroxide is a more clever way to say it that’s less wrong, but still fails to really capture the polar nature of H2O.

I found it amusing well into college.

The article was good, without the "Morons" at the end directed at Hangzhou Sage chemical company. It didn't need that, and it reeks a little of racism to pretend they're morons for working with FOOF, considering how much he lauded respect on Streng for doing so. The article already had good comic effect without needing to do it at someone else's expense whether it was racist or just cruel and dismissive.

They don't work with it though.

The insult was for abusing that catalogue and falsely claiming they could commercially produce and ship something that they could not, and I think it was fairly deserved. I don't really see any sort of racial dogwhistles or subtext here, this reads like a small snipe over questionable business practices.

I think the pint is that it’s clearly a fake listing as no one could safely handle 1kg of the stuff.

I think he was making fun of them for the fake listing. Offering 1kg of FOOF in a chemical database is like offering a nuclear warhead with free shipping on Amazon. Both are so ridiculously dangerous that they will surely not be publicly accessible.

Sometimes I wonder if China is still PO'd about the Opium Wars or something.

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