Ammonium tetrathiotungstate

Ammonium tetrathiotungstate is a chemical compound with the chemical formula (NH₄)₂WS₄.^[3][4]

Ammonium tetrathiotungstate

Names
IUPAC name azane;bis(sulfanylidene)tungsten;sulfanide
Identifiers
CAS Number	13862-78-7 N
3D model (JSmol)	Interactive image
ChemSpider	13547274
ECHA InfoCard	100.156.973
EC Number	628-727-4
PubChem CID	53393497
InChI InChI=1S/2H3N.2H2S.2S.W/h2*1H3;2*1H2;;;/p-2 Key: CCFCMIWYHMKPAO-UHFFFAOYSA-L
SMILES N.N.[SH-].[SH-].S=[W]=S
Properties
Chemical formula	H8N2S4W
Molar mass	348.16 g·mol−1
Appearance	yellow to orange crystals
Density	2.71 g/cm3 (hydrate)
Solubility in water	soluble
Hazards
GHS labelling:[1]
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P264, P280, P302+P352, P321, P332+P313, P362[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

Ammonium tetrathiotungstate can be obtained by the reaction of tungstic acid, ammonia, and hydrogen sulfide in a water bath at 65-70°C:^[5]

H₂WO₄ + 2NH₃·H₂O + 4H₂S → (NH₄)₂WS₄ + 6H₂O

Physical properties

Ammonium tetrathiotungstate forms yellow to orange crystals, soluble in water.^[6][7]

The compound decomposes under heat to produce tungsten trisulfide at 170-280°C and tungsten disulfide at 260-500°C.^[8]

Uses

The compound is used in materials science and catalysis.^[7]