Potassium ethyl xanthate (PEX) is an organosulphur compound that is pale yellow and has a pungent odour. It is non-hygroscopic and exists as anhydrous salt, and is relatively stable at high pH.
Xanthate salts are prepared by the action of alcohols on carbon disulfide. The alkoxide is generated in situ from potassium hydroxide:
CH3CH2OH + CS2 + KOH → CH3CH2OCS2K + H2O
Potassium ethyl xanthate is a pale yellow powder that is relatively 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.
Potassium ethyl xanthate is used as a reagent for extraction of metal ions into organic solvents and in the preparation of 2-mercapto benzimidazoles and 2-mercapto benzoxazoles by reacting with o-phenylenediamines and o-amino phenols respectively.
It acts as a precursor in the production of unsymmetrical sulfides through cross-coupling reaction and as a floatation agent in the mining industry.
PEX is also used in accelerating vulcanization in rubber industry.
It is used as a precipitating agent in wetting metallurgical industry. It is also involved in the determination of cadmium in water samples by substoichiometric radiochemical method and the adsorption of colloidal dye disperse Blue 3 onto pretreated polyester fabric.