M. Douglas Wray

Death Chemistry

From Bifurcated Rivets and orginally from Corante:

Things I Won’t Work With: Dioxygen Difluoride


Posted by Derek

The latest addition to the long list of chemicals that I never hope to encounter takes us back to the wonderful world of fluorine chemistry. I’m always struck by how much work has taken place in that field, how long ago some of it was first done, and how many violently hideous compounds have been carefully studied. Here’s how the experimental prep of today’s fragrant breath of spring starts:

The heater was warmed to approximately 700C. The heater block glowed a dull red color, observable with room lights turned off. The ballast tank was filled to 300 torr with oxygen, and fluorine was added until the total pressure was 901 torr. . .

And yes, what happens next is just what you think happens: you run a mixture of oxygen and fluorine through a 700-degree-heating block. “Oh, no you don’t,” is the common reaction of most chemists to that proposal, “. . .not unless I’m at least a mile away, two miles if I’m downwind.” This, folks, is the bracingly direct route to preparing dioxygen difluoride, often referred to in the literature by its evocative formula of FOOF.

Well, “often” is sort of a relative term. Most of the references to this stuff are clearly from groups who’ve just been thinking about it, not making it. Rarely does an abstract that mentions density function theory ever lead to a paper featuring machine-shop diagrams, and so it is here. Once you strip away all the “calculated geometry of. . .” underbrush from the reference list, you’re left with a much smaller core of experimental papers.

And a hard core it is! This stuff was first prepared in Germany in 1932 by Ruff and Menzel, who must have been likely lads indeed, because it’s not like people didn’t respect fluorine back then. 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). And that’s at room temperature. At seven hundred freaking degrees, fluorine starts to dissociate into monoatomic radicals, thereby losing its gentle and forgiving nature. But that’s how you get it to react with oxygen to make a product that’s worse in pretty much every way.

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Holy shit. Read this. Here’s an excerpt:

“…gas mixture was heated to 700°C and was then rapidly cooled on the outer surface of stainless steel tubes. The tubes were refrigerated by a liquid oxygen..”

Children starve and die while we make these horrors? I lose hope for mankind.

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