Fulminic acid

This chemical was known since the early 1800s through its salts and via the products of reactions in which it was proposed to exist, ==Structure==

Fulminic acid was long believed to have a structure of H–O–N+≡C−. It wasn't until the 1966 isolation and analysis of a pure sample of fulminic acid that this structural idea was conclusively disproven. The chemical that actually has that structure, isofulminic acid (a tautomer of the actual fulminic acid structure) was eventually detected in 1988. This predicted C–H bond length is unusually short, likely an artifact of the linear fit. Accurately modeling its structure using quantum chemical computations has proven similarly challenging. ==Synthesis==

A convenient synthesis involves flash pyrolysis of certain oximes. In contrast to earlier syntheses, this method avoids the use of highly explosive metal fulminates. ==References==