mercaptotriethoxysilane

Mercaptotriethylsulfide is an organosulfur compound commonly used as a reagent and ligand in synthetic chemistry. The systematic IUPAC name is 1,1,1‑tri­ethyl‑3‑sulfa­n‑2‑yl‑methane, and it is often abbreviated as TEMS. The molecular formula is C6H15S. It appears as a colorless liquid with a faint fishy odor that disappears upon standing. The melting point of the pure compound is −41 °C and the boiling point is 140 °C at atmospheric pressure. The density is 0.89 g cm‑3 and the refractive index is 1.45.

The synthesis of mercaptotriethylsulfide is typically achieved by the reduction of the corresponding disulfide, (Et3S)2, with a hydride donor such as sodium borohydride in a solvent of ethanol or methanol. Alternatively, the precursor trithiocarbonate can be converted by a thiol‑exchange reaction with triethylamine followed by protonation. Reaction conditions are usually mild (0–25 °C) and the product is isolated by distillation or by extraction from the reaction mixture.

Mercaptotriethylsulfide acts as a versatile ligand in coordination chemistry. It forms stable complexes with transition metals such as palladium, nickel, and copper, and these complexes are useful as precatalysts in cross‑coupling reactions and in the synthesis of heterocycles. In polymer chemistry, the thiol group of the compound can undergo thiol‑ene radical reactions, enabling the modular synthesis of sulfide‑cross‑linked networks. The compound is also employed as a catalyst in the synthesis of thioethers and as a scavenger for metal ions in analytical chemistry.

Safety data indicate that mercaptotriethylsulfide is moderately irritating to skin and eyes and may cause respiratory irritation if inhaled. It is flammable, with a flash point of 45 °C. The compound should be handled under a fume hood, with gloves and protective eyewear. In case of accidental ingestion, symptoms may include nausea, vomiting and abdominal pain; medical attention should be sought immediately. The compound should be disposed of following institutional hazardous waste protocols.