Thioformic acid

Thioformic acid is a chemical compound with the molecular formula. As the simplest thiocarboxylic acid, it has been the subject of studies on its properties which may be extrapolated to more complex thiocarboxylic acids.
Like other thiocarboxylic acids, thioformic acid can occur in either of two tautomers. The ratio of the two is dependent on solvent and other factors.
Thioformic acid has been detected in the interstellar medium near the giant molecular cloud G+0.693–0.027 and the hot core G31.41+0.31.