Bis(trimethylsilyl)sulfide


Bis sulfide is the chemical compound with the formula 2S. Often abbreviated 2S, this colourless, vile-smelling liquid is a useful aprotic source of "S2−" in chemical synthesis.

Synthesis

The reagent is prepared by treating trimethylsilyl chloride with anhydrous sodium sulfide:
2S must be protected from air because it hydrolyzes readily:

Use in synthesis

Bissulfide is a reagent for the conversion of metal oxides and chlorides into the corresponding sulfides. This transformation exploits the affinity of silicon 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.

Safety

2S reacts exothermically with water, releasing toxic H2S.