Dihydroxymethylidene

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Dihydroxymethylidene (also called carbonous or carbonic(II) acid) has the formula C(OH)2. It is an unstable tautomer of formic acid and is mainly detected in the gas phase; there is no evidence it exists in solution. It can be produced in the gas phase by high-vacuum flash pyrolysis of oxalic acid. The molecule is bent, with an O–C–O angle of about 105.6 degrees in its most stable form. It is only stable at very low temperatures (around 10 kelvin); at higher temperatures it rearranges to formic acid. It is related to carbenes, which are often short-lived.