Dicarbon monoxide. Wikipedia is shockingly poor in information about it, but “stable” is certainly not the first word I’d use to describe it.
From the third sentence in the wiki page:
It is, however, so extremely reactive that it is not encountered in everyday life.
So yeah, not at all stable.
Well, it seems Wikipedia was wrong at least about the second half of that sentence
I was about to say, you got way too many things that absolutely will bond with that with no hesitation. Thats a very unstable molecule.
Alternatively for a full octet on every atom, oxiryne, which does not exist and does not have a wiki page. It’s basically acetylene with its arms chopped off and the stumps dislocated, bent back, and stapled together with an oxygen atom.
You could also do something like a cross between https://en.m.wikipedia.org/wiki/Ethylene_oxide and https://en.m.wikipedia.org/wiki/Acetylene (the fuel responsible for the hottest welding flames) but remove the hydrogens and then have the carbons do a triple bond to make https://pubchem.ncbi.nlm.nih.gov/compound/Epoxy-acetylene
Considering ethylene oxide is already so unstable as fuck though due to its strained structure that it’s used as the main component in thermobaric weapons and this would be even more strained with a very unstable triple carbon bond, I don’t know if that would be an improvement. This ring would also likely cause mega cancer when it’s not exploding, pretty much all the https://en.m.wikipedia.org/wiki/Epoxide rings cause cancer and this one is particularly unstable (though I don’t really know if this one would because its not an alkening agent, which is why the other ones are so hostile, this one would be so reactive that it likely would immediately create some cancer causing compounds as soon as it met biological tissue).
Not that I know that is really possible to make. Chatgpt hallucinates a pathway and I never took organic chemistry so I can’t really criticize it. Google doesn’t really present with any answers. I’d imagine you’d need very low temperatures and an esoteric pathway.
Oh, cumulene, I swear on my knees.
