Potassium ethyl xanthate

Potassium ethyl xanthate

Names
IUPAC name potassium O-ethylcarbonodithioate
Other names potassium ethylxanthogenate potassium-O-ethyl dithiocarbonate
Identifiers
CAS Number	140-89-6 Y
3D model (JSmol)	Interactive image
ChemSpider	8491 Y
ECHA InfoCard	100.004.946
PubChem CID	2735045
CompTox Dashboard (EPA)	DTXSID6042315
InChI InChI=1S/C3H6OS2.K/c1-2-4-3(5)6;/h2H2,1H3,(H,5,6);/q;+1/p-1 Y Key: JCBJVAJGLKENNC-UHFFFAOYSA-M Y InChI=1S/C3H6OS2.K/c1-2-4-3(5)6;/h2H2,1H3,(H,5,6);/q;+1/p-1
SMILES [K+].[S-]C(=S)OCC
Properties
Chemical formula	C3H5KOS2
Molar mass	160.29 g·mol−1
Appearance	Pale yellow powder
Density	1.263 g/cm3
Melting point	225 to 226 °C (437 to 439 °F; 498 to 499 K)
Boiling point	decomposes
Acidity (pKa)	approximately 1.6
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Potassium ethyl xanthate (KEX) is an organosulfur compound with the chemical formula CH₃CH₂OCS₂K. It is a pale yellow powder that is used in the mining industry for the separation of ores. Unlike the related sodium ethyl xanthate, the potassium salt exists as an anhydrous salt.

Production and properties

Xanthate salts are prepared by the action of alkoxides on carbon disulfide. The alkoxide is often generated in situ from potassium hydroxide:

CH₃CH₂OH + CS₂ + KOH → CH₃CH₂OCS₂K + H₂O

Potassium ethyl xanthate is a pale yellow powder that is stable at high pH but rapidly hydrolyses at pH <9 at 25 °C. Unlike the sodium derivative, potassium xanthate crystallizes as the anhydrous salt and is nonhygroscopic.

Applications

Potassium ethyl xanthate is used in the mining industry as flotation agent for extraction of the ores of copper, nickel, and silver. The method exploits the affinity of these "soft" metals for the organosulfur ligand.

Potassium xanthate is a useful reagent for preparing xanthate esters from alkyl and aryl halides. The resulting xanthate estes are useful intermediates in organic synthesis.

Safety

The LD50 is 683 mg/kg (oral, rats) for potassium ethyl xanthate.