text: The S-oxides of thiocarbonyl compounds are known as thiocarbonyl S-oxides: (RC=S=O, and thiocarbonyl S,S-dioxides or sulfenes, RC=SO). The thione S-oxides have also been known as sulfines, and while IUPAC considers this term obsolete, the name persists in the literature. These compounds are well known with extensive chemistry. Examples include syn-propanethial-S-oxide and sulfene.