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IUPAC name Bis(trimethylsilyl) sulfide
Other names Hexamethyldisilathiane
CAS number 3385-94-2
RTECS number 3
Molecular formula C6H18S2Si
Molar mass 178.44 g/mol
Appearance colourless liquid, stench
Density 0.846 g/cm3
Boiling point

164 °C

Solubility in water hydrolysis
Solubility in other solvents ethers
Refractive index (nD) 1.4586
Dipole moment 1.85 D
Main hazards toxic
R-phrases 10-23/24/25
S-phrases 36/37/39-45
Related Compounds
Related compounds B2S3, SiS2
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Bis(trimethylsilyl) sulfide is the chemical compound with the formula ((CH3)3Si)2S. Often abbreviated (tms)2S, this colourless, vile-smelling liquid is a useful aprotic source of “S2-“ in chemical synthesis.[1]



The reagent is prepared by treating trimethylsilyl chloride with anhydrous sodium sulfide:[2]

2 (CH3)3SiCl + Na2S → ((CH3)3Si)2S + 2 NaCl

((CH3)3Si)2S must be protected from air because it hydrolyzes readily:

((CH3)3Si)2S + H2O → ((CH3)3Si)2O + H2S


(tms)2S is primarily used to convert oxides and chlorides into the corresponding sulfides.[3] This transformation exploits the affinity of silicon(IV) for oxygen and halides. An idealized reaction is:

((CH3)3Si)2S + MO → ((CH3)3Si)2O + MS

In a similar way, it has been used in the conversion of aldehydes and ketones to the corresponding thiones.[4][5]


((CH3)3Si)2S reacts exothermically with water, releasing toxic H2S.


  1. ^ Matulenko, M. A. (2004.). "Bis(trimethylsilyl) Sulfide". Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette), J. Wiley & Sons, New York. doi:10.1002/047084289..
  2. ^ So, J.-H.; Boudjouk, P. (1992). "Hexamethyldisilathiane", in Russell, N. G.: Inorganic Syntheses, 30. DOI:10.1002/9780470132609.ch11. ISBN 0-471-54470-1. 
  3. ^ Lee, S. C.; Holm, R. H., "Nonmolecular Metal Chalcogenide/Halide Solids and Their Molecular Cluster Analogues", Angewandte Chemie, International Edition English, 1990, volume 29, pages 840-856.
  4. ^ A. Capperucci, A. Degl’Innocenti, P. Scafato, P. Spagnolo (1995). "Synthetic Applications of Bis(trimethylsilyl)sulfide: Part II. Synthesis of Aromatic and Heteroaromatic o-Azido-Thioaldehydes". Chemistry Letters 24: 147. doi:10.1246/cl.1995.147.
  5. ^ W. M. McGregor, D. C. Sherrington (1993). "Some Recent Synthetic Routes to Thioketones and Thioaldehydes"". Chemical Society Reviews 22: 199 - 204. doi:10.1039/CS9932200199.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Bis(trimethylsilyl)sulfide". A list of authors is available in Wikipedia.
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