Potassium ethyl xanthate

Last updated
Potassium ethyl xanthate
Potassium ethyl xanthate.png
Potassium ethyl xanthate 3D ball.png
Names
Preferred IUPAC name
Potassium O-ethylcarbonodithioate
Other names
  • Potassium ethylxanthogenate
  • Potassium ethylxanthate
  • Potassium-O-ethyl dithiocarbonate
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.004.946 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 205-439-3
PubChem CID
UNII
  • InChI=1S/C3H6OS2.K/c1-2-4-3(5)6;/h2H2,1H3,(H,5,6);/q;+1/p-1 Yes check.svgY
    Key: JCBJVAJGLKENNC-UHFFFAOYSA-M Yes check.svgY
  • InChI=1S/C3H6OS2.K/c1-2-4-3(5)6;/h2H2,1H3,(H,5,6);/q;+1/p-1
  • [K+].[S-]C(=S)OCC
Properties
CH3CH2OCS2K
Molar mass 160.29 g·mol−1
AppearancePale yellow powder
Density 1.263 g/cm3 [1]
Melting point 225 to 226 °C (437 to 439 °F; 498 to 499 K)
Boiling point decomposes
Acidity (pKa)approximately 1.6
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg
Warning
H228, H302, H315, H319, H332, H335
P210, P240, P241, P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P370+P378, P403+P233, P405, P501
Related compounds
Other cations
Sodium ethyl xanthate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

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. It is a potassium salt of ethyl xanthic acid.

Contents

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: [2]

CH3CH2OH + CS2 + KOH → CH3CH2OCS2K + H2O

Potassium ethyl xanthate is a pale yellow powder that is stable at high pH, but rapidly hydrolyses below pH = 9:

CH3CH2OCS2K + H+ → CH3CH2OH + CS2 + K+

Oxidation gives diethyl dixanthogen disulfide:

4 CH3CH2OCS2K + 2 H2O + O2 → 2 (CH3CH2OCS2)2 + 4 KOH

KEX is a source of ethylxanthate coordination complexes. For example (CH3CH2OCS2)3M have been prepared from KEX for M = Cr, In, Co.[ clarification needed ] [3]

Applications

Potassium ethyl xanthate is used in the mining industry as flotation agent for extraction of the ores of copper, nickel, and silver. [4] 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 esters are useful intermediates in organic synthesis. [5]

Safety

The LD50 is 103 mg/kg (oral, rats) for potassium ethyl xanthate. [4]

Related Research Articles

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<span class="mw-page-title-main">Thiol</span> Any organic compound having a sulfanyl group (–SH)

In organic chemistry, a thiol, or thiol derivative, is any organosulfur compound of the form R−SH, where R represents an alkyl or other organic substituent. The −SH functional group itself is referred to as either a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogue of alcohols, and the word is a blend of "thio-" with "alcohol".

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<span class="mw-page-title-main">Thioester</span> Organosulfur compounds of the form R–SC(=O)–R’

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Xanthate usually refers to a salt of xanthic acid. The formula of the salt of xanthic acid is [R−O−CS2]M+ ,. Xanthate also refers to the anion [R−O−CS2]. Xanthate also may refer to an ester of xanthic acid. The formula of xanthic acid is R−O−C(=S)−S−H, while the formula of the esters of xanthic acid is R−O−C(=S)−S−R', where R and R' are organyl groups. The salts of xanthates are also called O-organyl dithioates. The esters of xanthic acid are also called O,S-diorganyl esters of dithiocarbonic acid. The name xanthate is derived from Ancient Greek ξανθός xanthos, meaning “yellowish, golden”, and indeed most xanthate salts are yellow. They were discovered and named in 1823 by Danish chemist William Christopher Zeise. These organosulfur compounds are important in two areas: the production of cellophane and related polymers from cellulose and for extraction of certain ores. They are also versatile intermediates in organic synthesis.

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The Chugaev elimination is a chemical reaction that involves the elimination of water from alcohols to produce alkenes. The intermediate is a xanthate. It is named for its discoverer, the Russian chemist Lev Aleksandrovich Chugaev (1873-1922), who first reported the reaction sequence in 1899.

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<span class="mw-page-title-main">Sodium ethyl xanthate</span> Chemical compound

Sodium ethyl xanthate (SEX) is an organosulfur compound with the chemical formula CH3CH2OCS2Na. It is a pale yellow powder, which is usually obtained as the dihydrate. Sodium ethyl xanthate is used in the mining industry as a flotation agent. A closely related potassium ethyl xanthate (KEX) is obtained as the anhydrous salt.

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Potassium amyl xanthate (/pəˈtæsiəm ˌæmɪl ˈzænθeɪt/) is an organosulfur compound with the chemical formula CH3(CH2)4OCS2K. It is a pale yellow powder with a pungent odor that is soluble in water. It is widely used in the mining industry for the separation of ores using the flotation process.

References

  1. Report 5 (1995) p. 5
  2. This report gives a detailed recipe for potassium ethyl xanthate: Charles C. Price, Gardner W. Stacy (1948). "p-Nitrophenyl) Sulfide". Organic Syntheses . 28: 82. doi:10.15227/orgsyn.028.0082.
  3. Galsbøl, F.; Schäffer, C. E. (1967). "Tris (O-Ethyldithiocarbonato) Complexes of Tripositive Chromium, Indium, and Cobalt". Inorganic Syntheses. 10: 42–49. doi:10.1002/9780470132418.ch6.
  4. 1 2 Kathrin-Maria Roy (2005). "Xanthates". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a28_423. ISBN   3527306730.
  5. One of several procedures using xanthate esters: Fabien Gagosz and Samir Z. Zard (1948). "A Xanthate-Transfer Approach to α-Trifluoromethylamines". Organic Syntheses . 84: 32.; Collective Volume, vol. 11, p. 212