The third sentence of the article: "Only certain lighter than air gases are suitable as lifting gases."
Diborane, among other things, autoignites in an oxygen atmosphere at 38C, and also burns on contact with water. It manages a rare NFPA fire diamond of 4 4 3.
It is tough to be a less practical lifting gas than hydrogen cyanide or hydrogen fluoride, but I think diborane manages it.
>Because of the exothermicity of its reaction with oxygen, diborane has been tested as a rocket propellant.[32] ... Diborane is pyrophoric gas. Commercially available adducts are typically used instead ... The toxic effects of diborane are mitigated because the compound is so unstable in air. The toxicity toward laboratory rats has been investigated.[38]
Note that hydrogen fluoride was the first thing featured on that column, even before the name of the series settled down: https://archive.md/gX3xF
> HF has actually been used right out of the cylinder for a long time in Merrifield peptide synthesizers. It’s the traditional way to cleave the peptide off the resin at the final step, so there are actually a lot of people who’ve used the stuff. But it’s in a dedicated apparatus that is (that had better be) well sealed, and people treat it with due respect. At a former employer of mine, there was an accident with one of these machines right before I joined the company. The shout “HF LEAK!” went out into the halls, and I’m told that the whole area set a never-to-be-equaled evacuation record.
By the fire diamond metric, HF is relatively tame, at 4 0 1, except that anything with a health rating of 4 ("very short exposure could cause death or major residual injury") is unsuitable for most purposes. So you can't set it on fire. Doesn't matter.
Thanks for that link, I really do enjoy his writing. "Relatively tame" isn't something I expect to see with a health rating of 4, but I suppose it's an accurate statement when you're talking 4x3 ratings.
Diborane, among other things, autoignites in an oxygen atmosphere at 38C, and also burns on contact with water. It manages a rare NFPA fire diamond of 4 4 3.
It is tough to be a less practical lifting gas than hydrogen cyanide or hydrogen fluoride, but I think diborane manages it.
>Because of the exothermicity of its reaction with oxygen, diborane has been tested as a rocket propellant.[32] ... Diborane is pyrophoric gas. Commercially available adducts are typically used instead ... The toxic effects of diborane are mitigated because the compound is so unstable in air. The toxicity toward laboratory rats has been investigated.[38]