Bis(trimethylsilyl) sulfide is the chemical compound with the formula ((CH<sub>3</sub>)<sub>3</sub>Si)<sub>2</sub>S. Often abbreviated (tms)<sub>2</sub>S, this colourless, vile-smelling liquid is a useful aprotic source of "S<sup>2âÂÂ</sup>" in chemical synthesis.
The reagent is prepared by treating trimethylsilyl chloride with anhydrous sodium sulfide:
((CH<sub>3</sub>)<sub>3</sub>Si)<sub>2</sub>S must be protected from air because it hydrolyzes readily:
Bis(trimethylsilyl)sulfide is a reagent for the conversion of metal oxides and chlorides into the corresponding sulfides. This transformation exploits the affinity of silicon(IV) for oxygen and halides. An idealized reaction is:
In a similar way, it has been used in the conversion of aldehydes and ketones to the corresponding thiones.
((CH<sub>3</sub>)<sub>3</sub>Si)<sub>2</sub>S reacts exothermically with water, releasing toxic H<sub>2</sub>S.