Bis(trimethylsilyl)sulfide
# Bis(trimethylsilyl)sulfide

Bis(trimethylsilyl) sulfide is the chemical compound with the formula $((CH_3)_3Si)_2S.$ Often abbreviated $(tms)_2S,$ this colourless, vile-smelling liquid is a useful aprotic source of $"S^{2−}"$ in chemical synthesis.

## Synthesis

The reagent is prepared by treating trimethylsilyl chloride with anhydrous sodium sulfide:

    2 $(CH_3)_3SiCl$ + $Na_2S$ → $((CH_3)_3Si)_2S$ + 2 NaCl

$((CH_3)_3Si)_2S$ must be protected from air because it hydrolyzes readily:

    $((CH_3)_3Si)_2S$ + $H_2O$ → $((CH_3)_3Si)_2O$ + $H_2S$

## Use in synthesis

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:

    $((CH_3)_3Si)_2S$ + MO → $((CH_3)_3Si)_2O$ + MS

In a similar way, it has been used in the conversion of aldehydes and ketones to the corresponding thiones.

## Safety

$((CH_3)_3Si)_2S$ reacts exothermically with water, releasing toxic $H_2S.$

