Article · Wikipedia archive · Last revised Jul 20, 2026

Copper monosulfide

Copper monosulfide is a chemical compound of copper and sulfur with the empirical formula CuS. It occurs in nature as the dark indigo blue mineral covellite. It is one of a number of binary compounds of copper and sulfur, and has attracted interest because of its potential uses in catalysis and photovoltaics. It is a moderate conductor of electricity.

Last revised
Jul 20, 2026
Read time
≈ 6 min
Length
1,355 w
Citations
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Source
Wikipedia ↗
Copper monosulfide
source ↗
Names
IUPAC name
Copper sulfide
Other names
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.884
EC Number
  • 215-271-2
RTECS number
  • GL8912000
UNII
  • InChI=1S/Cu.S checkY
    Key: BWFPGXWASODCHM-UHFFFAOYSA-N checkY
  • InChI=1/Cu.S/rCuS/c1-2
    Key: BWFPGXWASODCHM-BLKBWTQCAT
  • [Cu]=S
Properties2
CuS
Molar mass 95.61 g·mol−1
Appearance black hexagonal crystals
Density 4.76 g/cm3
Melting point 507 °C (945 °F; 780 K) (transitions)
3.3×10−5 g/100 ml (18 °C (64 °F))
Solubility product (Ksp) of CuS
 6×10−37 (25 °C (77 °F))1
−2.0×10−6 cm3/mol
1.45
Structure
hexagonal
Thermochemistry2
47.8 J⋅mol−1·K-1
66.5 J⋅mol−1·K-1
−53.1 kJ⋅mol−1
−53.6 kJ⋅mol−1
Hazards
NIOSH (US health exposure limits):3
PEL (Permissible)
 TWA 1 mg/m3 (as Cu)
REL (Recommended)
 TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)
 TWA 100 mg/m3 (as Cu)
Related compounds
Other anions
Other cations
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Copper monosulfide is a chemical compound of copper and sulfur with the empirical formula CuS.4 It occurs in nature as the dark indigo blue mineral covellite.4 It is one of a number of binary compounds of copper and sulfur (see copper sulfide for an overview of this subject), and has attracted interest because of its potential uses in catalysis and photovoltaics.56 It is a moderate conductor of electricity.7

Manufacturing

A black colloidal precipitate of copper monosulfide is formed when hydrogen sulfide (H2S) is bubbled through solutions of Cu(II) salts.8 This is the basis of its industrial production.

Special forms of CuS for certain applications can be prepared by melting an excess of sulfur with copper(I) sulfide or by precipitation with hydrogen sulfide from a solution of anhydrous copper(II) chloride in anhydrous ethanol. Nanoparticles of CuS can be prepared by reaction of dissolved copper(II) chloride with thioglycolic acid.9

The reaction of copper with molten sulfur followed by boiling sodium hydroxide and the reaction of sodium sulfide with aqueous copper sulfate will also produce copper sulfide.

CuS structure and bonding

Copper sulfide crystallizes in the hexagonal crystal system, and this is the form of the mineral covellite. There is also an amorphous high pressure form, which on the basis of the Raman spectrum has been described as having a distorted covellite structure.10 An amorphous room temperature semiconducting form produced by the reaction of a Cu(II) ethylenediamine complex with thiourea has been reported, which transforms to the crystalline covellite form at 30 °C (86 °F).11

The crystal structure of covellite has been reported several times, and whilst these studies are in general agreement on assigning the space group P63/mmc there are small discrepancies in bond lengths and angles between them.121314 The structure was described as "extraordinary" by Wells and is quite different from Copper(II) oxide, but similar to Copper(II) selenide (referred to as Klockmannite).15 The covellite unit cell contains 6 formula units (12 atoms) in which:

  • 4 Cu atoms have tetrahedral coordination (see illustration).
  • 2 Cu atoms have trigonal planar coordination (see illustration).
  • 2 pairs of S atoms are only 207.1 picometers apart14 indicating the existence of an S-S bond (a disulfide unit).
  • the 2 remaining S atoms form trigonal planar triangles around the copper atoms, and are surrounded by five Cu atoms in a pentagonal bipyramid (see illustration).
  • The S atoms at each end of a disulfide unit are tetrahedrally coordinated to 3 tetrahedrally coordinated Cu atoms and the other S atom in the disulfide unit (see illustration).

The formulation of copper sulfide as CuIIS (i.e. containing no sulfur-sulfur bond) is clearly incompatible with the crystal structure, and also at variance with the observed diamagnetism as a Cu(II) compound would have a d9 configuration and be expected to be paramagnetic.168

Studies using X-ray photoelectron spectroscopy (XPS) indicate that all of the copper atoms have an oxidation state of +1.17181920 This contradicts a formulation based on the crystal structure and obeying the octet rule that is found in many textbooks (e.g.821) describing CuS as containing both CuI and CuII i.e. (Cu+)2Cu2+(S2)2−S2−. An alternative formulation as (Cu+)3(S2−)(S2)− was proposed and supported by calculations. The formulation should not be interpreted as containing radical anion, but rather that there is a delocalized valence "hole".224 Electron paramagnetic resonance studies on the precipitation of Cu(II) salts indicates that the reduction of Cu(II) to Cu(I) occurs in solution.23

Local structures in covellite
  • ball-and-stick model of part of the crystal structure of covellite
    ball-and-stick model of part of the crystal structure of covellite
  • trigonal planar coordination of copper
    trigonal planar coordination of copper
  • tetrahedral coordination of copper
    tetrahedral coordination of copper
  • trigonal bipyramidal coordination of sulfur
    trigonal bipyramidal coordination of sulfur
  • coordination of sulfur-note[clarification needed] disulfide unit
    coordination of sulfur-note disulfide unit
See also

See also

References

References

  1. Rollie J. Myers (1986). "The new low value for the second dissociation constant for H2S: Its history, its best value, and its impact on the teaching of sulfide equilibria". J. Chem. Educ. 63 (8): 687–690. Bibcode:1986JChEd..63..687M. doi:10.1021/ed063p687.
  2. Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). Boca Raton, Florida: CRC Press. pp. 4–60, 4–127, 5–11. ISBN 9781498754293.
  3. "NIOSH Pocket Guide to Chemical Hazards".
  4. Liang, W.; Whangbo, M.-H. (February 1993). "Conductivity anisotropy and structural phase transition in Covellite CuS". Solid State Communications. 85 (5): 405–408. Bibcode:1993SSCom..85..405L. doi:10.1016/0038-1098(93)90689-K.
  5. Kuchmii, S.Y.; Korzhak A.V.; Raevskaya A.E.; Kryukov A.I. (2001). "Catalysis of the Sodium Sulfide Reduction of Methylviologene by CuS Nanoparticles". Theoretical and Experimental Chemistry. 37 (1). New York: Springer: 36–41. doi:10.1023/A:1010465823376. S2CID 91893521.
  6. Mane, R.S.; Lokhande C.D. (June 2000). "Chemical deposition method for metal chalcogenide thin films". Materials Chemistry and Physics. 65 (1): 1–31. doi:10.1016/S0254-0584(00)00217-0.
  7. Wells, Alexander Frank (1984). Structural Inorganic Chemistry (5th ed.). Oxford University Press. p. 1142. ISBN 0-19-855370-6.
  8. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1181. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  9. Li, Yuebin; Lu, Wei; Huang, Qian; Li, Chun; Chen, Wei (October 2010). "Copper Sulfide Nanoparticles for Photothermal Ablation of Tumor Cells". Nanomedicine. 5 (8): 1161–1171. doi:10.2217/nnm.10.85.
  10. Peiris, M.; Sweeney, J.S.; Campbell, A.J.; Heinz, D.L. (1996). "Pressure-induced amorphization of covellite, CuS". J. Chem. Phys. 104 (1): 11–16. Bibcode:1996JChPh.104...11P. doi:10.1063/1.470870.
  11. Grijalva, H.; Inoue, M.; Boggavarapu, S.; Calvert, P. (1996). "Amorphous and crystalline copper sulfides, CuS". J. Mater. Chem. 6 (7): 1157–1160. doi:10.1039/JM9960601157.
  12. Oftedal, Ivar (1 December 1932). "Die Kristallstruktur des Covellins (CuS)". Zeitschrift für Kristallographie - Crystalline Materials (in German). 83 (1–6): 9–25. doi:10.1524/zkri.1932.83.1.9. S2CID 101164006.
  13. Berry, L.G. (1954). "The crystal structure of covellite CuS and klockmannite CuSe". American Mineralogist. 39: 504.
  14. Evans Jr., H.T.; Konnert, J. (1976). "Crystal structure refinement of covellite". American Mineralogist. 61: 996–1000.
  15. Wells, A. F. (1984). Structural inorganic chemistry (5th ed.). Oxford [Oxfordshire] : New York: Clarendon Press; Oxford University Press. ISBN 0-19-855370-6.
  16. "Magnetic susceptibility of the elements and inorganic compounds" (PDF). Archived from the original (PDF) on 2012-01-12.
  17. Nakai, I.; Sugitani, Y.; Nagashima, K.; Niwa, Y. (January 1978). "X-ray photoelectron spectroscopic study of copper minerals". Journal of Inorganic and Nuclear Chemistry. 40 (5): 789–791. doi:10.1016/0022-1902(78)80152-3.
  18. Folmer, J.C.W; Jellinek, F (December 1980). "The valence of copper in sulphides and selenides: An X-ray photoelectron spectroscopy study". Journal of the Less Common Metals. 76 (1–2): 153–162. doi:10.1016/0022-5088(80)90019-3.
  19. Folmer, J.C.W.; Jellinek, F.; Calis, G.H.M. (January 1988). "The electronic structure of pyrites, particularly CuS2 and Fe1−xCuxSe2: An XPS and Mössbauer study". Journal of Solid State Chemistry. 72 (1): 137–144. Bibcode:1988JSSCh..72..137F. doi:10.1016/0022-4596(88)90017-5.
  20. Goh, Siew Wei; Buckley, Alan N.; Lamb, Robert N. (February 2006). "Copper(II) sulfide?". Minerals Engineering. 19 (2): 204–208. Bibcode:2006MiEng..19..204G. doi:10.1016/j.mineng.2005.09.003.
  21. Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999), Advanced Inorganic Chemistry (6th ed.), New York: Wiley-Interscience, ISBN 0-471-19957-5
  22. Nozaki, Hiroshi; Shibata, Kenji; Ohhashi, Naoki (April 1991). "Metallic hole conduction in CuS". Journal of Solid State Chemistry. 91 (2): 306–311. Bibcode:1991JSSCh..91..306N. doi:10.1016/0022-4596(91)90085-V.
  23. Luther, George W.; Theberge, Stephen M.; Rozan, Tim F.; Rickard, David; Rowlands, C. C.; Oldroyd, Anthony (1 February 2002). "Aqueous Copper Sulfide Clusters as Intermediates during Copper Sulfide Formation". Environmental Science & Technology. 36 (3): 394–402. Bibcode:2002EnST...36..394L. doi:10.1021/es010906k. PMID 11871554.